Parking assistive apparatus

0001The present invention relates to a parking assistive apparatus (parking assistor) that assist in a parking procedure by displaying an image of a view, as viewed in a direction in which a vehicle moves, on a display located in a passenger compartment.

0002A typical parking assistor, which is described in Japanese Patent Publication No. <patcit id="pcit0001" dnum="JP1610702A"><text>1610702</text></patcit> or Japanese Patent Publication No. <patcit id="pcit0002" dnum="JP2610146B"><text>2610146</text></patcit>, includes a camera and a display. The camera acquires an image of a rear view from a vehicle, and the display shows the acquired image. When a parking procedure is started, the parking assistor assumes a path along which the vehicle is moved during the procedure in accordance with the steering angle of the steering wheel. The assumed path appears on the display, in addition to the image of the rear view from the vehicle. The parking procedure is thus continued with the aid of the image on the display. This makes it easy for the driver to complete the parking procedure.

0003For example, if the vehicle is parked in a space between a pair of vehicles that are parked along a road shoulder, the steering wheel of the vehicle is first rotated in one direction such that the vehicle is reversed while turning in the corresponding direction. Subsequently, the steering wheel is rotated in the other direction such that the vehicle is reversed while turning in the corresponding direction. However, the aforementioned parking assistor does not inform the driver of an optimal timing at which the rotating direction of the steering wheel should be switched. Accordingly, the parking assistor is not sufficiently assistive in the parking procedure in which the rotating direction of the steering wheel must be switched. As a result, the parking procedure is not sufficiently simplified for the driver.

0004Furthermore, document <patcit id="pcit0003" dnum="FR2785383A"><text>FR-A-2 785 383</text></patcit> discloses a method of and an apparatus for assisting a driver for parking a vehicle in a parking lot. The parking lot is basically arranged between different cars or objects of obstruction arranged on the road side. The objects of obstruction which determine the available parking space are detected with respect to a start position of the vehicle and a parking trajectory is calculated to be taken by the vehicle in order to arrive at a final parking position between the other vehicles or objects. The calculated trajectory is a function of parking space dimensions, vehicle dimensions, the vehicle start position and the braking and steering characteristics of the vehicle. The trajectory is divided into various portions constituting a route from the start position to the final parking position. The vehicle is moved in each subdivided trajectory and is significantly slowed-down or stopped at the end of each portion of the trajectory.

0005Accordingly, it is an objective of the present invention to provide a parking assistive apparatus that informs a driver of an optimal timing at which the rotating direction of a steering wheel should be switched.

0006This object is accomplished according to the present invention by a parking assistive apparatus the features of which are set out in the appended claims.

0007The present invention provides a parking assistive apparatus as set out in claim 1.

0008Hence, the control means instructs the display to indicate a steering information that informs the driver of a timing at which the steering device must be rotated in the opposite direction in accordance with the assumed path.

0009Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

0010The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which: <ul id="ul0001" list-style="none"><li><figref idref="f0001">Fig. 1</figref> is a view schematically showing a vehicle equipped with a parking assistive apparatus or a parking assistor of a first embodiment according to the present invention;</li><li><figref idref="f0002">Fig. 2</figref> is a block diagram showing the parking assistor of <figref idref="f0001">Fig. 1</figref>;</li><li><figref idref="f0003">Fig. 3</figref> is a side view showing a camera attached to the vehicle;</li><li><figref idref="f0003">Fig. 4</figref> is a plan view showing a field of view of the camera;</li><li><figref idref="f0004">Fig. 5</figref> is a view showing a display field of a display;</li><li><figref idref="f0004">Fig. 6</figref> is a plan view showing an initial position and a target position of the vehicle that is parallel-parked in a parking space;</li><li><figref idref="f0005">Fig. 7</figref> is a plan view showing the movement of the vehicle that is parallel-parked in the parking space;</li><li><figref idref="f0006">Fig. 8</figref> is a chart explaining an assisted parallel parking procedure;</li><li><figref idref="f0007">Fig. 9</figref> is a chart explaining the assisted parallel parking procedure;</li><li><figref idref="f0008">Fig. 10</figref> is a chart explaining the assisted parallel parking procedure;</li><li><figref idref="f0009">Fig. 11</figref> is a plan view showing an initial position and a target position of a vehicle that is parallel-parked in a parking space in accordance with an assisted parallel parking procedure of a second embodiment according to the present invention;</li><li><figref idref="f0009">Figs. 12(a) and 12(b)</figref> are views each showing a display state of a display during the assisted parallel parking procedure of the second embodiment;</li><li><figref idref="f0010">Figs. 13(a) and 13(b)</figref> are views each showing a modified example of the display state of the display during the assisted parallel parking procedure of the first embodiment;</li><li><figref idref="f0010">Figs. 14(a) and 14(b)</figref> are views each showing a modified example of the display state of the display during the assisted parallel parking procedure of the first embodiment;</li><li><figref idref="f0010">Figs. 15(a) and 15(b)</figref> are views each showing a modified example of the display state of the display during the assisted parallel parking procedure of the second embodiment;</li><li><figref idref="f0010">Figs. 16(a) and 16(b)</figref> are views each showing a modified example of the display state of the display during the assisted parallel parking procedure of the second embodiment;</li><li><figref idref="f0011">Fig. 17</figref> is a view schematically showing a vehicle equipped with a parking assistor of another embodiment according to the present invention; and</li><li><figref idref="f0011">Fig. 18</figref> is a block diagram showing the parking assistor of <figref idref="f0011">Fig. 17</figref>.</li></ul>

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(First embodiment)

0011A first embodiment of the present invention will now be described with reference to <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008">Figs. 1 to 10</figref>.

0012<figref idref="f0001">Fig. 1</figref> schematically shows a vehicle 2 equipped with a parking assistor 1 of the first embodiment. The parking assistor 1 includes a camera (CCD camera) 11, a steering angle sensor 13, a reverse sensor 14, a parking switch 15, a yaw rate sensor 16, a display 17, a speaker 18, and a controller 20. The camera 11 acquires an image of a rear view from the vehicle 2 when the vehicle 2 is reversed during a parking procedure. The steering angle sensor 13 detects a steering angle of a steering wheel 12. The reverse sensor 14 detects that a lift lever (not shown) is shifted to "reverse" position. The parking switch 15 is manipulated to activate the parking assistor 1. The yaw rate sensor 16 detects a rotational angular speed of the vehicle 2 with respect to the axis of the vehicle 2.

0013The camera 11 is located, for example, at the substantial middle of the rear side of the vehicle 2 such that the optical axis of the camera 11 faces downward. More specifically, as shown in <figref idref="f0003">Fig. 3</figref>, the camera 11 is attached to the substantial middle portion of the rear side of the vehicle 2 with the optical axis of the camera 11 facing downward at a predetermined angle (for example, thirty degrees). Further, as shown in <figref idref="f0003">Fig. 4</figref>, the camera 11 includes a wide angle lens that has a field of view corresponding to an angle of 140 degrees. The field of view along the axis of the vehicle 2 is, for example, eight meters.

0014The steering angle sensor 13 is a known sensor that detects a steering angle of the steering wheel 12. The steering angle sensor 13 is, for example, accommodated in the interior of the steering wheel 12.

0015The parking switch 15, which is operated to activate the parking assistor 1, is located, for example, in the vicinity of a central console box such that the driver easily manipulates the parking switch 15. The parking switch 15 includes a pair of operational mode switches, or a first mode switch 15a and a second mode switch 15b, as shown in <figref idref="f0002">Fig. 2</figref>. When the vehicle 2 is parallel-parked, the second switch 15b is turned on. Otherwise, the first mode switch 15a is turned on. That is, the parking switch 15 is selectively switched between a parking mode corresponding to the first switch 15a and a parking mode corresponding to the second switch 15b.

0016The display 17 is located, for example, at the central console box. The display 17 shows a live image of the rear view from the vehicle 2 combined with a graphic image as a reference for an assisted parking procedure. <figref idref="f0004">Fig. 5</figref> shows a display field of the display 17.

0017The speaker 18 diffuses prescribed audio instructions corresponding to each step of the parking procedure, which will be later described.

0018The controller 20 is accommodated, for example, in the interior of an instrument panel. The camera 11, the steering angle sensor 13, the reverse sensor 14, the parking switch 15, and the yaw rate sensor 16 each send a signal to the controller 20. Depending on the signal, the controller 20 displays the image of the rear view from the vehicle 2 combined with the graphic image while generating a corresponding audio instruction.

0019<figref idref="f0002">Fig. 2</figref> diagrammatically shows a control system of the parking assistor 1. As shown in <figref idref="f0002">Fig. 2</figref>, the controller 20 of the parking assistor 1 includes a central processing unit (CPU) 21, a graphic image generating circuit 22, a superimposing circuit 23, a synchronization separator circuit 24, and an audio instruction generating circuit 25. The graphic image generating circuit 22 generates a graphic image that appears on the display 17. The superimposing circuit 23 superimposes a signal indicating the graphic image on the rear view image from the vehicle 2, which is acquired by the camera 11. The synchronization separator circuit 24 extracts a synchronization signal from the image of the camera 11 and supplies the signal to the graphic image generating circuit 22. The audio instruction generating circuit 25 generates an audio instruction that is diffused by the speaker 18.

0020As shown in <figref idref="f0004">Figs. 6</figref> and <figref idref="f0005">7</figref>, when the vehicle 2 is parallel-parked in a parking space S located leftward as viewed from the driver, the steering wheel 12 is first rotated leftward such that the vehicle 2 is reversed while turning leftward. Subsequently, the steering wheel 12 is rotated rightward such that the vehicle 2 is reversed while turning rightward. In contrast, when the vehicle 2 is parallel-parked in a parking space located rightward as viewed from the driver, the steering wheel 12 is rotated in opposite directions to those described above such that the vehicle 2 is reversed in corresponding directions. In this embodiment, if the second mode switch 12b is turned on, the parking procedure of the vehicle 2 is assisted by the image appearing on the display 17 and the audio instructions diffused by the speaker 18.

0021For example, as shown in <figref idref="f0004">Fig. 6</figref>, if the vehicle 2 is parallel-parked in the parking space S, which is located leftward as viewed from the driver, the vehicle 2 is first stopped at a predetermined initial position V1. The steering wheel 12 is then rotated leftward. A path along which the vehicle 2 is moved from the initial position V1 to a terminating point of the path, or a target position V2, is determined in accordance with the steering angle of the steering wheel 12. As shown in <figref idref="f0007">Fig. 9</figref>, the display 17 shows a parking frame Ic that indicates the terminating point of the path, or the target position V2. More specifically, the steering angle of the steering wheel 12 is adjusted to locate the parking frame Ic at a desired position in the parking space S, as viewed on the display 17. Subsequently, the vehicle 2 is reversed while maintaining the steering angle of the steering wheel 12 at the adjusted value.

0022<figref idref="f0004">Fig. 6</figref> geometrically explains the initial position V1 and the target position V2 of the vehicle 2. As shown in <figref idref="f0004">Fig. 6</figref>, when the vehicle 2 is located at the initial position V1 or the target position V2, a fore-and-aft direction of the vehicle 2, or a longitudinal direction of the vehicle 2, extends parallel with a longitudinal direction of the parking space S. The point O represents a midpoint between the rear wheels of the vehicle 2. If the vehicle 2 is moved from the initial position V1 to the target position V2, the point O is moved correspondingly by a movement amount dL in the longitudinal direction of the parking space S and by a movement amount dW in the lateral direction of the parking space S. The controller 20 stores a longitudinal dimension L and a lateral dimension W of the parking space S. The dimensions L, W do not represent actual dimensions of the parking space S, which are varied case by case. Instead, the dimensions L, W are predetermined values corresponding to a minimum space needed for parking the vehicle 2.

0023As shown in <figref idref="f0004">Fig. 6</figref>, a line M crosses a reference point P, which is located at a corner of the parking space S, and intersects the camera 11. It is defined that the vehicle 2 is located at the initial position V1 when the line M forms an angle α with respect to the longitudinal direction of the parking space S. The lateral interval between the reference point P and a left side of the vehicle 2 located at the initial position V1 is indicated by a reference index Wa. The longitudinal interval between the reference point P and the point O, which corresponds to the midpoint between the rear wheels of the vehicle 2 located at the initial position V1, is indicated by a reference index La. When the vehicle 2 is located at the initial position V1, the rate La/Wa becomes a predetermined constant value.

0024When the vehicle 2 is located at the target position V2, the point O is longitudinally spaced from the line M by an interval L1 and is located on a line N that extends parallel with the line M. In other words, it is defined that the vehicle 2 is located at the target position V2 when the point O is located on the line N. The interval L1 is a predetermined value selected in accordance with the dimensions L, W of the parking space S, which are stored in the controller 20.

0025As shown in <figref idref="f0004">Fig. 6</figref>, if the steering wheel 12 is rotated leftward when the vehicle 2 is stopped at the initial position V1 with the second mode switch 12b turned on, an assumed path of the point O during the parking procedure is obtained in relation to the steering angle of the steering wheel 12, using a known method. The method is described in, for example, Japanese Unexamined Patent Publication No. <patcit id="pcit0004" dnum="JP11334470A"><text>11-334470</text></patcit>. Further, when the steering direction of the vehicle 2 is switched at a later stage, the steering wheel 12 is rotated rightward to a maximum steering angle.

0026The assumed path of the point O includes a first arched path C1 and a second arched path C2. The first arched path C1 is determined in relation to the steering angle of the steering wheel 12 when the vehicle 2 is steered leftward. The second arched path C2 is determined in relation to the steering angle of the steering wheel 12 when the vehicle 2 is steered rightward, which is the maximum steering angle. The radius of the first arched path C1, or a first turning radius, is indicated by a reference index R1, and the center of the first arched path C1 is indicated by a reference index O1. Likewise, the radius of the second arched path C2, or a second turning radius, is indicated by a reference index R2, and the center of the second arched path C2 is indicated by a reference index O2.

0027More specifically, the starting point of the first arched path C1 corresponds to the point O of the vehicle 2 located at the initial position V1. The second arched path C2 forms a circumscribed circle with respect to the first arched path C1. Further, a tangential line of the second arched path C2 that crosses the point at which the second arched path C2 crosses the line N extends parallel with the longitudinal direction of the parking space S. In other words, if a certain arch with the second turning radius R2 forms a circumscribed circle with respect to the first arched path C1 and a tangential line of the arch that crosses the point at which the arch crosses the line N extends parallel with the longitudinal direction of the parking space S, the arch is selected as the second arched path C2. The point at which the second arched path C2 crosses the line N corresponds to the point O of the vehicle 2 located at the target position V2, or the terminating point of the assumed path of the vehicle 2. During the parking procedure with the parking assistor 1, the display 17 shows the parking frame Ic that represents the terminating point of the assumed path (see <figref idref="f0007">Fig. 9</figref>).

0028The center O2 of the second arched path C2 is located on a line Q, which extends parallel with the line N. The longitudinal interval between the lines N, Q is equal to the second turning radius R2 and is indicated by R2·cotα.

0029The first arched path C1 contacts the second arched path C2 at a point P1. The point P1 is located on a line K, which crosses the center O1 of the first arched path C1 and the center O2 of the second arched path C2. An angle at which the point O is rotated along the first arched path C1 with respect to the center O1, or a rotational angle θ, is equal to an angle at which the point O is rotated along the second arched path C2 with respect to the center O2, which is also defined as the rotational angle θ. When the point O of the vehicle 2 reaches the point P1, the steering direction of the steering wheel 12 is switched from the leftward direction to the rightward direction.

0030When the vehicle 2 is moved from the initial position V1 to the target position V2 in the parking procedure, the longitudinal movement amount dL and the lateral movement amount dW are represented by the following equations (1) and (2): <maths id="math0001" num="(1)"><math display="block"><mi mathvariant="normal">d</mi><mo>⁢</mo><mi mathvariant="normal">L</mi><mo>=</mo><mfenced><mi mathvariant="normal">R</mi><mo>⁢</mo><mn>1</mn><mo>+</mo><mi mathvariant="normal">R</mi><mo>⁢</mo><mn>2</mn></mfenced><mo>⋅</mo><mi>sin</mi><mi mathvariant="normal">θ</mi></math><img file="EP1160146B2_D0001.tif" /></maths><maths id="math0002" num="(2)"><math display="block"><mi mathvariant="normal">d</mi><mo>⁢</mo><mi mathvariant="normal">W</mi><mo>=</mo><mfenced><mi mathvariant="normal">R</mi><mo>⁢</mo><mn>1</mn><mo>+</mo><mi mathvariant="normal">R</mi><mo>⁢</mo><mn>2</mn></mfenced><mo>⋅</mo><mfenced><mn>1</mn><mo>−</mo><mi>cos</mi><mi mathvariant="normal">θ</mi></mfenced></math><img file="EP1160146B2_D0002.tif" /></maths>

0031As is clear from the equations (1) and (2), the location of the target position V2 relative to the initial position V1 is determined in relation to the first turning radius R1, the second turning radius R2, and the rotational angle θ.

0032Assume that the lateral movement amount dW is substantially equal to the total of the lateral dimension W and the lateral interval Wa, as shown in <figref idref="f0004">Fig. 6</figref>. The lateral dimension W of the parking space S is the predetermined value, as aforementioned. The lateral movement amount dW is obtained by the equation (2). The lateral interval Wa is thus determined in relation to the lateral movement amount dW and the lateral dimension W. As described, the rate La/Wa becomes the predetermined constant value when the vehicle 2 is located at the initial position V1. Accordingly, the longitudinal interval La is obtained in relation to the lateral interval Wa. The position of a reference point P relative to the vehicle 2 located at the initial position V1 is thus determined. The reference point P corresponds to a corner of the parking space S, thus indicating an interfering object. It is thus possible to determine a path of the vehicle 2 that prevents the vehicle 2 from interfering with the interfering object during the parking procedure, depending on the position of the reference point P relative to the initial position V1.

0033As shown in <figref idref="f0004">Fig. 6</figref>, when the vehicle 2 is located at the target position V2 in the parking space S, the point O of the vehicle 2 is spaced from the rear end of the parking space S by a predetermined clearance ΔL. The clearance ΔL is slightly larger than the interval between the point O and the rear end of the vehicle 2. The longitudinal dimension L, which is the predetermined value used in computation for the parking procedure, is selected such that the clearance ΔL is ensured between the rear end of the vehicle 2 and the rear end of the parking space S.

0034Next, the assisted parking procedure of the vehicle 2 will be described in detail with reference to <figref idref="f0005 f0006 f0007 f0008">Figs. 7 to 10</figref>. As shown in <figref idref="f0005">Fig. 7</figref>, the vehicle 2 is parallel-parked along a road shoulder in the parking space S that is located between a pair of parked vehicles 2a, 2b, which are also parallel-parked along the road shoulder. In <figref idref="f0005">Fig. 7</figref>, the reference numerals in brackets each correspond to a step of the parking procedure, thus indicating a state of the vehicle 2 during the step. The reference numerals in brackets of <figref idref="f0005">Fig. 7</figref> correspond to those of <figref idref="f0006 f0007 f0008">Figs. 8 to 10</figref>.

(Moving to the initial position V1)

0035As indicated by step (1) of <figref idref="f0005">Fig. 7</figref>, the vehicle 2 is first stopped at a side of the parked vehicle 2a, which is located forward from the parking space S, such that the longitudinal direction of the vehicle 2 extends substantially parallel with the longitudinal direction of the parking space S. The vehicle 2 is stopped at a position slightly forward from the initial position V1, which is shown in <figref idref="f0004">Fig. 6</figref>.

0036Subsequently, the second mode switch 15b is turned on to activate the parking assistor 1. Then, as shown in step (1) of <figref idref="f0006">Fig. 8</figref>, the CPU 21 displays the image of the rear view from the vehicle 2, which is acquired by the camera 11, in combination with an image of the assumed path Ia of the rear end of the vehicle 2, on the display 17. The assumed path Ia is obtained in accordance with the steering angle of the steering wheel 12 using a known method, which is described in, for example, Japanese Unexamined Patent Publication No. <patcit id="pcit0005" dnum="JP11334470A"><text>11-334470</text></patcit>. The assumed path Ia appears on the display 17, as projected on the ground.

0037When the shift lever 14 is shifted to "reverse" position, the reverse sensor 14 is activated. Accordingly, as shown in step (2) of <figref idref="f0006">Fig. 8</figref>, the CPU 21 diffuses audio instructions from the speaker 18 through the audio instruction generating circuit 25. The audio instructions include "the assisted parking procedure is started", "reverse the vehicle until the reference marker corresponds to the rear end of the adjacent vehicle", and "rotate the steering wheel to locate the parking frame at a desired parking position". The speaker 18 diffuses the instructions in this order. Meanwhile, as shown in step (3) of <figref idref="f0006">Fig. 8</figref>, the CPU 21 deletes the assumed path Ia from the display 17 and displays the rear view image acquired by the camera 11 and a reference marker Ib, which is mentioned in the corresponding audio instruction, on the display 17.

0038The second mode switch 15b may be turned on before or after the shift lever is shifted to "reverse" position.

0039The reference marker Ib corresponds to a vertical plane B shown in <figref idref="f0004">Fig. 6</figref> and indicates the position of the vertical plane B on the display 17. As shown in <figref idref="f0004">Fig. 6</figref>, the vertical plane B extends along the camera 11 of the vehicle 2 and is inclined at a predetermined angle with respect to the camera 11. The vertical plane B extends parallel with the line M. Thus, if the vehicle 2 is located at the initial position V1, the vertical plane B overlaps with the line M, as shown in <figref idref="f0004">Fig. 6</figref>. The position of the line M is selected such that the vehicle 2 does not interfere with the reference point P of the parking space S during the parking procedure. Accordingly, as long as the parking procedure is started with the vehicle 2 located at the initial position V1, the vehicle 2 is prevented from interfering with the reference point P of the parking space S, which represents an interfering object.

0040The reference point P of <figref idref="f0004">Fig. 6</figref> corresponds to a rear right corner of the parked vehicle 2a, as shown in <figref idref="f0005">Fig. 7</figref>. Thus, when the reference marker Ib substantially corresponds to the rear right corner of the parked vehicle 2a, as viewed on the display 17, the vehicle 2 is located at a position corresponding to the initial position V1 with respect to the parked vehicle 2a, as shown in <figref idref="f0004">Fig. 6</figref>.

0041More specifically, in accordance with an audio instruction corresponding to step (2) of <figref idref="f0006">Fig. 8</figref>, the vehicle 2 is reversed straight and stopped when the reference marker Ib substantially corresponds to the rear right corner of the parked vehicle 2a, as viewed on the display 17 (see step (3) of <figref idref="f0006">Fig. 8</figref>). In this state, the vehicle 2 is located at a position corresponding to the initial position V1 of <figref idref="f0004">Fig. 6</figref>, and the rate La/Wa becomes the predetermined constant value, as explained with reference to <figref idref="f0004">Fig. 6</figref>.

(Determining a target position V2)

0042Subsequently, the steering wheel 12 is rotated leftward in accordance with an audio instruction corresponding to step (2) of <figref idref="f0006">Fig. 8</figref>. When the steering angle of the steering wheel 12, which is detected by the steering angle sensor 13, becomes equal to or larger than a predetermined value, the CPU 21 generates the following audio instruction: "reverse the vehicle after the parking frame corresponds to the parking space", from the speaker 18 through the audio instruction generating circuit 25, as shown in step (4) of <figref idref="f0006">Fig. 8</figref>. The CPU 21 then displays the parking frame Ic, which is mentioned in the audio instruction, on the display 17, as indicated by step (5) of <figref idref="f0007">Fig. 9</figref>.

0043The parking frame Ic indicates the outline of the vehicle 2 located at the target position V2 of <figref idref="f0004">Fig. 6</figref>, as projected on the ground. The parking frame Ic is superimposed on the image of the camera 11, which also appears on the display 17. As aforementioned, the point O of the vehicle 2 at the target position V2 indicates the terminating point of the assumed path along which the point O of the vehicle 2 is moved during the parking procedure. The assumed path of the point O, as well as its terminating point, is selected in relation to the steering angle of the steering wheel 12. Thus, the parking frame Ic, which represents the terminating point of the assumed path, moves across the display 17 in accordance with variation in the steering angle of the steering wheel 12. The steering angle of the steering wheel 12 is adjusted to locate the parking frame Ic at a desired position in the parking space S, as viewed on the display 17, in accordance with the audio instruction of step (2) in <figref idref="f0006">Fig. 8</figref>.

0044The front end of the parking frame Ic corresponds to the front end of the vehicle 2. The rear end of the parking frame Ic corresponds to a position slightly rearward from the rear end of the vehicle 2. This ensures a sufficient clearance between the vehicle 2 and the parked vehicle 2b, which is located rearward from the vehicle 2 when the vehicle 2 is parked at the target position V2 in the parking space S.

0045As indicated by step (6) in <figref idref="f0007">Fig. 9</figref>, the steering wheel 12 is rotated leftward until the parking frame Ic is moved to a desired position (for example, a position near the road shoulder) in the parking space S, as viewed on the display 17. As aforementioned, since it is assumed that the lateral movement amount dW is substantially equal to the total of the lateral dimension W and the lateral interval Wa, the lateral interval Wa and the longitudinal interval La are obtained. In other words, the position of the vehicle 2 relative to the reference point P when the vehicle 2 is located at the initial position V1 is determined. That is, when the steering wheel 12 is rotated, the CPU 21 determines the assumed path of the vehicle 2 and detects the position of the vehicle 2 relative to the reference point P, in relation to the steering angle of the steering wheel 12. The CPU 21 then judges whether or not the assumed path of the vehicle 2 interferes with the rear right corner of the parked vehicle 2a, which is indicated by the reference point P.

0046If the CPU 21 decides that the assumed path of the vehicle 2 interferes with the reference point P, or the rear right corner of the parked vehicle 2a, the CPU 21 generates a requirement for changing the steering angle of the steering wheel 12. The requirement is viewed on the display 17 or is diffused as an audio instruction from the speaker 18.

0047Accordingly, the steering angle of the steering wheel 12, the assumed path of the vehicle 2, and the target position V2 are selected to prevent the vehicle 2 from interfering with the parked vehicle 2a during the parking procedure.

(Reversing while turning leftward)

0048Once the steering angle of the steering wheel 12 is determined, the vehicle 2 is reversed with the steering angle of the steering wheel 12 maintained at the determined value, in accordance with the audio instruction corresponding to step (4) of <figref idref="f0006">Fig. 8</figref>. Since the steering wheel 12 is maintained as rotated leftward, the vehicle 2 is reversed while turning leftward from the initial position V1. In this state, the CPU 21 obtains an angular change of the vehicle 2, or a leftward turning amount of the vehicle 2, with respect to the initial position V1, based on detection results of the steering angle sensor 13 and the yaw rate sensor 16. The CPU 21 then determines the position of the vehicle 2 relative to the parking space S in relation to the obtained angular change of the vehicle 2. When the angle of the vehicle 2 is altered, the CPU 21 acknowledges that the vehicle 2 starts to reverse and generates the following audio instruction: reverse the vehicle without moving the steering wheel" from the speaker 18 through the audio instruction generating circuit 25, as shown in step (7) of <figref idref="f0007">Fig. 9</figref>. Meanwhile, the CPU 21 deletes the reference marker Ib and the parking frame Ic from the display 17 and re-displays the assumed path Ia of the rear end of the vehicle 2 on the display 17.

0049The vehicle 2 is continuously reversed without changing the steering angle of the steering wheel 12, in accordance with the audio instruction of step (7) of <figref idref="f0007">Fig. 9</figref>. In this state, the CPU 21 compares a current value of the leftward turning amount of the vehicle 2, which is obtained in relation to the detection results of the steering angle sensor 13 and the yaw rate sensor 16, with a desired value at which the steering direction of the vehicle 2 should be switched. The desired value of the leftward turning amount of the vehicle 2 is determined in accordance with the first arched path C1 of <figref idref="f0004">Fig. 6</figref>. When the current value of the leftward turning amount of the vehicle 2 reaches a predetermined value that is smaller than the desired value, the CPU 21 acknowledges that the steering wheel 12 must be rotated rightward without delay.

0050Subsequently, as shown in step (9) of <figref idref="f0007">Fig. 9</figref>, the CPU 21 generates the following audio instruction: "rotate the steering wheel rightward to the maximum angle after the assumed rightward path reaches the road shoulder", from the speaker 18 through the audio instruction generating circuit 25. Meanwhile, as shown in step (10) of <figref idref="f0008">Fig. 10</figref>, the CPU 21 displays an assumed path Id along which the vehicle 2 is steered rightward, in addition to the assumed path Ia, which is currently shown on the display 17. More specifically, the assumed path Id indicates a path along which the rear end of the vehicle 2 is moved if the steering wheel 12 is rotated rightward to the maximum angle at the current position of the vehicle 2. The assumed path Id appears on the display 17, as projected on the ground.

0051In accordance with the audio instruction of step (9) of <figref idref="f0007">Fig. 9</figref>, the vehicle 2 is continuously reversed while turning leftward without changing the steering angle of the steering wheel 12 until the assumed path Id reaches the road shoulder, as viewed on the display 17. When the assumed path Id reaches the road shoulder, the vehicle 2 is stopped, as shown in step (11) of <figref idref="f0008">Fig. 10</figref>. The steering wheel 12 is then rotated rightward to the maximum steering angle.

0052Alternatively, immediately before the steering wheel 12 is rotated rightward, the CPU 21 may generate the following audio instruction: "stop the vehicle and rotate the steering wheel rightward to the maximum angle".

(Reversing while turning rightward)

0053The CPU 21 acknowledges that the steering wheel 12 is rotated rightward to the maximum angle by means of the steering angle sensor 13. The CPU 21 then generates the following instruction: "reverse the vehicle without moving the steering wheel" from the speaker 18 through the audio instruction generating circuit 25, as shown in step (12) of <figref idref="f0008">Fig. 10</figref>. Subsequently, as shown in step (13) of <figref idref="f0008">Fig. 10</figref>, the CPU 21 deletes the assumed path Id from the display 17 and displays a pair of side indicating lines Ie and a pair of clearance indicating lines If, in addition to the assumed path Ia.

0054Each side indicating line Ie indicates a hypothetical line section extending along a corresponding lateral side of the vehicle 2, as viewed on the display 17. Each clearance indicating line If indicates a hypothetical line section spaced from the rear end of the vehicle 2 by an associated predetermined distance, as viewed on the display 17. For example, one interval indicating line If corresponds to a hypothetical line section spaced from the rear end of the vehicle 2 by fifty centimeters, and the other corresponds to a hypothetical line section spaced from the rear end of the vehicle 2 by one meter. The lines Ie, If appear on the display 17 as projected on the ground.

0055In accordance with the audio instruction corresponding to step (12) of <figref idref="f0008">Fig. 10</figref>, the vehicle 2 is reversed with the steering angle of the steering wheel 12 maintained as rotated rightward to the maximum angle. The vehicle 2 is thus reversed while turning rightward from the position at which the rotating direction of the steering wheel 12 is switched, or the position corresponding to the contact point P1 between the first arched path C1 and the second arched path C2, as shown in <figref idref="f0004">Fig. 6</figref>. In this state, the driver acknowledges the positions of the side indicating lines Ie relative to the road shoulder and the positions of the clearance indicating lines If relative to the parked vehicle 2b, which is located rearward from the parking space S, by means of the image on the display 17, as indicated by step (13) of <figref idref="f0008">Fig. 10</figref>.

0056Further, the CPU 21 obtains a current angular difference of the vehicle 2 with respect to the initial position V1, in accordance with the detection results of the steering angle sensor 13 and the yaw rate sensor 16. If the current angular difference becomes smaller than a predetermined value, the CPU 21 determines that the vehicle 2 has reached a position close to the target position V2, or that the longitudinal direction of the vehicle 2 currently extends substantially parallel with the longitudinal direction of the parking space S. The CPU 21 then generates the following audio instruction: "check the rear view", from the speaker 18 through the audio instruction generating circuit 25, as shown in step (14) of <figref idref="f0008">Fig. 10</figref>. The rear view from the vehicle 2 is thus checked directly without looking at the display 17 or indirectly by looking at the display 17, in accordance with the audio instruction. The vehicle 2 is then stopped at an optimal position. In this state, for example, an image corresponding to step (15) of <figref idref="f0008">Fig. 10</figref> appears on the display 17.

0057When determining that the angular change per unit time of the vehicle 2 becomes smaller than a predetermined value based on the detection results of the steering angle sensor 13 and the yaw rate sensor 16, the CPU 21 acknowledges that the vehicle 2 is stopped. The CPU 21 then generates the following audio instruction: "the assisted parking procedure is completed", from the speaker 18 through the audio instruction generating circuit 25, as indicated by step (16) of <figref idref="f0008">Fig. 10</figref>.

0058Subsequently, for example, the neutral position of the steering wheel 12 is restored, and the vehicle 2 is moved to adjust the position of the vehicle 2 in the longitudinal direction of the parking space S.

0059During steps (6) through (16), the CPU 21 judges whether or not the vehicle 2 is moving along the assumed path, which is determined in relation to the steering angle of the steering wheel 12 when the vehicle 2 is stopped at the initial position V1, based on the detection results of the sensors 13, 16. If the CPU 21 judges that the vehicle 2 is not moving along the assumed path, an audio instruction is diffused, for example, to inform the driver of the fact that the vehicle 2 is located offset from the assumed path. Alternatively, the CPU 21 indicates information needed for correcting the moving path of the vehicle 2 on the display 17. Further, if the moving path of the vehicle 2 is not correctable, the CPU 21 generates an audio instruction for repeating the parking procedure from the beginning.

0060In addition, if the parking space S in which the vehicle 2 should be parked is located rightward from the driver, a corresponding assisted parking procedure is performed in the same manner as the above description.

0061The first embodiment has the following advantages.

0062The assumed path Id, which appears on the display 17, enables the driver to easily acknowledge when the rotating direction of the steering wheel 12 should be switched in the assisted parking procedure. The parking procedure is thus performed easily such that the vehicle 2 is parked at a desired position easily and accurately.

0063The position of the vehicle 2 relative to the parking space S, or the position of the vehicle 2 relative to the target position V2, is detected based on the detection results of the steering angle sensor 13 and the yaw rate sensor 16. The assumed path Id appears on the display 17 at an appropriate timing in accordance with the detected position of the vehicle 2 relative to the parking space S.

0064Further, in accordance with the detected position of the vehicle 2 relative to the parking space S, or the position of the vehicle 2 relative to the target position V2, the CPU 21 judges whether or not the vehicle 2 is moving along the assumed path. If the vehicle 2 is not moving along the assumed path, the driver is informed of the fact that the vehicle 2 is located offset from the assumed path. This enables the driver to park the vehicle 2 at an optimal position in the parking space S without interfering with an object.

0065When the rotating direction of the steering wheel 12 is switched and the assumed path Id no longer need be shown on the display 17, the assumed path Id is deleted from the display 17. Thus, no unnecessary indicators appear on the display 17. This makes it easy to view the image on the display 17.

0066When the rotating direction of the steering wheel 12 is switched, the steering wheel 12 is rotated to the maximum angle. This simplifies various computation processes that are performed during the parking procedure. Further, after the rotating direction of the steering wheel 12 is switched, the steering wheel 12 is easily maintained at a constant angle, which is the maximum angle.

0067The side indicating lines Ie and the interval indicating lines If appear on the display 17 at a final stage of the assisted parking procedure. This prevents the vehicle 2 from interfering with the object, and the position of the vehicle 2 relative to the parking space S is easily adjusted.

0068When the reference marker Ib substantially corresponds to the rear right corner of the parked vehicle 2a, which is indicated by the reference point P, the vehicle 2 is located at the initial position V1. In this state, the rate La/Wa becomes the predetermined constant value (see <figref idref="f0004">Fig. 6</figref>). In other words, when the vehicle 2 is located at the initial position V1, the vehicle 2 is located at a constant position relative to the reference point P. Further, the position of the parking frame Ic on the display 17 is determined in relation to the steering angle of the steering wheel 12 when the vehicle 2 is located at the initial position V1. The position of the parking frame Ic represents the target position V2 at which the vehicle 2 is parked. The lateral interval Wa between the vehicle 2 and the reference point P is obtained in accordance with the position of the parking frame Ic. The longitudinal interval La between the vehicle 2 and the reference point P is obtained in relation to the constant rate La/Wa and the lateral interval Wa. Accordingly, the parking assistor 1 of the first embodiment easily detects the position of the vehicle 2 relative to the reference point P when the vehicle 2 is located at the initial position V1, without employing an additional sensor.

0069As described, the position of the vehicle 2 relative to the reference point P when the vehicle 2 is located at the initial position V1 is determined such that the assumed path of the vehicle 2 is selected to prevent the vehicle 2 from interfering with the reference point P (the object) during the parking procedure.

(Second embodiment)

0070A second embodiment of the present invention will hereafter be described with reference to <figref idref="f0009">Figs. 11 to 12(b)</figref>. The description focuses on the difference between the first embodiment illustrated in <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008">Figs. 1 to 10</figref> and the second embodiment. More specifically, the initial position V1 of the second embodiment at which the vehicle 2 is initially located is determined depending only on the longitudinal interval La, unlike the first embodiment in which the initial position V1 is determined depending on the constant rate La/Wa.

0071<figref idref="f0009">Fig. 11</figref> corresponds to <figref idref="f0004">Fig. 6</figref>. In this embodiment, it is defined that the vehicle 2 is located at the initial position V1 when the longitudinal interval La between the reference point P and the point O, which corresponds to the midpoint between the rear wheels of the vehicle 2, becomes a predetermined constant value.

0072When the vehicle 2 is located at the target position V2, the point O is longitudinally spaced from the reference point P by an interval L11 and is located on a line T that extends parallel with the lateral direction of the vehicle 2. In other words, it is defined that the vehicle 2 is located at the target position V2 when the point O is located on the line T. Like the interval L1 of <figref idref="f0004">Fig. 6</figref>, the interval L11 is a predetermined value selected in accordance with the longitudinal dimension L and the lateral dimension W of the parking space S as well as the clearance ΔL, which are stored in the controller 20.

0073When the vehicle 2 is located at the initial position V1 with the second mode switch 15b turned on and the steering wheel 12 is rotated, the assumed path of the point O during the assisted parking procedure is determined in relation to the steering angle of the steering wheel 12, using a similar method to that of the first embodiment. However, the second arched path C2 of the second embodiment is determined in a different manner from that of the first embodiment. That is, in the second embodiment, if a certain arch with the second turning radius R2 forms a circumscribed circle with respect to the first arched path C1 and a tangential line of the arch that crosses the point at which the arch crosses the line T extends parallel with the longitudinal direction of the parking space S, the arch is selected as the second arched path C2. The point at which the second arched path C2 crosses the line T corresponds to the point O of the vehicle 2 located at the target position V2, which is the terminating point of the assumed path. Further, the center O2 of the second arched path C2 is located on the line T.

0074When the vehicle 2 is moved from the initial position V1 to the target position V2 in the parking procedure, the longitudinal movement amount dL and the lateral movement amount dW of the point O are obtained by the equations (1), (2), as explained about the first embodiment of <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008">Figs. 1 to 10</figref>. Further, when the vehicle 2 is located at the initial position V1, the longitudinal interval La becomes the predetermined constant value. In addition, it is assumed that the lateral movement amount dW is substantially equal to the total of the lateral dimension W and the lateral interval Wa, as shown in <figref idref="f0009">Fig. 11</figref>. Based on the assumption, the lateral interval Wa is obtained in relation to the lateral movement amount dW and the lateral dimension W, like the embodiment illustrated in <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008">Figs. 1 to 10</figref>. As a result, the position of the vehicle 2 relative to the reference point P when the vehicle 2 is located at the initial position V1 is determined.

0075Next, the assisted parking procedure of the second embodiment will be described with reference to <figref idref="f0009">Figs. 12(a) and 12(b)</figref>. The description focuses on the difference between the procedure of the first embodiment, which is shown in <figref idref="f0006 f0007 f0008">Figs. 8 to 10</figref>, and that of the second embodiment. In the second embodiment, the vehicle 2 is parallel-parked in the parking space S along a road shoulder. Like the first embodiment, the parking space S of the second embodiment is located between the parked vehicles 2a, 2b that are also parallel-parked along the road shoulder.

0076Like the first embodiment of <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008">Figs. 1 to 10</figref>, the vehicle 2 is stopped at a side of the parked vehicle 2a, which is located forward from the parking space S, such that the longitudinal direction of the vehicle 2 extends substantially parallel with the longitudinal direction of the parking space S. In this state, the vehicle 2 is stopped at a position slightly forward from the initial position V1, which is shown in <figref idref="f0009">Fig. 11</figref>.

0077Subsequently, the second mode switch 15b is turned on, thus activating the parking assistor 1. The steps corresponding to steps (1) and (2) of <figref idref="f0006">Fig. 8</figref> are thus performed. In the subsequent step, which corresponds to step (3) of <figref idref="f0006">Fig. 8</figref>, a reference marker Ig appears on the display 17, in addition to the image of the rear view from the vehicle 2 acquired by the camera 11, as shown in <figref idref="f0009">Fig. 12(a)</figref>. The reference marker Ig is mentioned in an audio instruction of this step.

0078The reference marker Ig of this step is different from the reference marker Ib of step (3) of <figref idref="f0006">Fig. 8</figref>. More specifically, the reference marker Ig indicates the position of a lateral line G of <figref idref="f0009">Fig. 11</figref>, as viewed on the display 17. As shown in <figref idref="f0009">Fig. 11</figref>, the line G is spaced longitudinally rearward from the point O by the interval La and laterally extends at a height that is substantially equal to that of the rear bumper of the vehicle 2. Thus, if the vehicle 2 is located at the initial position V1, the lateral line G crosses the reference point P, as shown in <figref idref="f0009">Fig. 11</figref>. The lateral interval La is selected to prevent the vehicle 2 from interfering with the reference point P of the parking space S during the parking procedure. Accordingly, if the assisted parking procedure is initiated with the vehicle 2 located at the initial position V1, the vehicle 2 is prevented from interfering with the reference point P of the parking space S, which indicates an interfering object.

0079As shown in <figref idref="f0009">Fig. 12(a)</figref>, the reference point P of <figref idref="f0009">Fig. 11</figref> corresponds to the rear right corner of the parked vehicle 2a. Thus, when the reference marker Ig substantially corresponds to the rear right corner of the parked vehicle 2a, as viewed on the display 17, the vehicle 2 is located at a position corresponding to the initial position V1 of <figref idref="f0009">Fig. 11</figref> with respect to the parked vehicle 2a.

0080More specifically, in accordance with an audio instruction of the step corresponding to step (2) of <figref idref="f0006">Fig. 8</figref>, the vehicle 2 is reversed straight and stopped when the reference marker Ig substantially corresponds to the rear right corner of the parked vehicle 2a, as viewed on the display 17 (see <figref idref="f0009">Fig. 12(a)</figref>). In this state, the vehicle 2 is stopped at a position corresponding to the initial position V1 of <figref idref="f0009">Fig. 11</figref> such that the longitudinal interval La becomes the predetermined constant value.

0081Next, the steering wheel 12 is rotated leftward in accordance with the audio instruction of the step corresponding to step (2) of <figref idref="f0006">Fig. 8</figref>. When the steering angle of the steering wheel 12, which is detected by the steering angle sensor 13, becomes equal to or greater than a predetermined value, the steps corresponding to steps (4), (5) of <figref idref="f0006">Fig. 8</figref> are performed. In the step corresponding to step (5) of <figref idref="f0006">Fig. 8</figref>, the parking frame Ic appears on the display 17, as shown in <figref idref="f0009">Fig. 12(b)</figref>. Since the target position V2 of the vehicle 2 is located on the line T, as shown in <figref idref="f0009">Fig. 11</figref>, the parking frame Ic moves laterally on the display 17 in relation to the steering angle of the steering wheel 12. The steering angle of the steering wheel 12 is adjusted to locate the parking frame Ic at a desired position in the parking space S, as viewed on the display 17.

0082The subsequent steps are identical to those described with reference to <figref idref="f0005 f0006 f0007 f0008">Figs. 7 to 10</figref>, and description thereof is omitted. Further, the second embodiment has the same advantages as those of the first embodiment.

0083The illustrated embodiments of the present invention may be modified as follows.

0084<figref idref="f0010">Figs. 13(a) and 13(b)</figref> show a modification of the first embodiment shown in <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008">Figs. 1 to 10</figref>. In this modification, the reference point P corresponds to the front left corner of the parked vehicle 2b, which is located rearward from the parking space S. When the reference marker Ib substantially corresponds to the front left corner of the parked vehicle 2b, the vehicle 2 is located at the initial position V1 such that the position of the vehicle 2 relative to the reference point P satisfies a certain condition.

0085<figref idref="f0010">Figs. 14(a) and 14(b)</figref> show a modification of the first embodiment shown in <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008">Figs. 1 to 10</figref>. In this modification, the reference point P corresponds to the front right corner of the parked vehicle 2b, which is located rearward from the parking space S. When the reference marker Ib substantially corresponds to the front right corner of the parked vehicle 2b, the vehicle 2 is located at the initial position V1 such that the position of the vehicle 2 relative to the reference point P satisfies a certain condition.

0086<figref idref="f0010">Figs. 15(a) and 15(b)</figref> show a modification of the second embodiment shown in <figref idref="f0009">Figs. 11 to 12(b)</figref>. In this modification, the reference point P corresponds to the rear wheels, or the rear wheel portions that contact the ground, of the parked vehicle 2a that is located forward from the parking space S. When the reference marker Ig substantially corresponds to the rear wheel portions of the parked vehicle 2a that contact the ground, the vehicle 2 is located at the initial position V1 such that the position of the vehicle 2 relative to the reference point P satisfies a certain condition.

0087<figref idref="f0010">Figs. 16(a) and 16(b)</figref> show a modification of the second embodiment shown in <figref idref="f0009">Figs. 11 to 12(b)</figref>. In this modification, the reference point P corresponds to the front end of the parked vehicle 2b, which is located rearward from the parking space S. When the reference marker Ig substantially corresponds to the front end of the parked vehicle 2b, the vehicle 2 is located at the initial position V1 such that the position of the vehicle 2 relative to the reference point P satisfies a certain condition.

0088As shown in <figref idref="f0011">Fig. 17 and 18</figref>, a manipulator such as a joystick 31 may replace the steering wheel 12. The manipulator 31 is manipulated to move the parking frame Ic to a desired position, as viewed on the display 17. In this case, the display 17 or the speaker 18 enables the driver to acquire a steering angle of the steering wheel 12 that is needed for moving the vehicle 2 to the finally selected position of the parking frame Ic.

0089In the illustrated embodiments, the second mode switch 15b is turned on to activate the parking assistor 1. However, the parking assistor 1 may be activated by means of a voice recognizing device, which recognizes a vocal instruction produced by the driver.

0090During the assisted parking procedure, a sensor that detects rotation of the wheels of the vehicle 2 or an acceleration sensor may detect that the vehicle 2 is stopped or started. Alternatively, a voice recognizing device may recognize a vocal announcement of the driver, thus detecting that the vehicle 2 is stopped or started.

0091During the assisted parking procedure, the position of the vehicle 2 relative to the parking space S may be detected depending only on the detection result of the yaw rate sensor 16. Further, the position of the vehicle 2 relative to the parking space S may be detected in accordance with a detection result of a sensor that detects rotation of the wheels of the vehicle 2. In addition, the position of the vehicle 2 relative to the parking space S may be detected in relation to a timer measurement.

0092During the assisted parking procedure, an object may be detected based on an image acquired by the camera 11 or a detection result of an object sensor. The object detection is used in determination of the path along which the vehicle 2 is moved during the parking procedure.

0093In the first embodiment shown in <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008">Figs. 1 to 10</figref>, the driver judges when the rotating direction of the steering wheel 12 should be switched based on the assumed path Id, which appears on the display 17. However, the driver may be informed of when the rotating direction of the steering wheel 12 should be switched through a prescribed image that appears on the display 17 or an audio instruction that is diffused from the speaker 18.

0094When the rotating direction of the steering wheel 12 is switched, the steering wheel 12 does not necessarily have to be rotated to the maximum angle. Instead, the steering wheel 12 may be rotated to a predetermined angle that is smaller than the maximum value.

0095When the assisted parking procedure is performed, all steps shown in <figref idref="f0006 f0007 f0008">Figs. 8 to 10</figref> do not necessarily have to be executed. For example, in accordance with the driver's skill, unnecessary steps may be omitted.

0096The present invention is not restricted to the illustrated parking procedure, which is a parallel parking procedure. However, the present invention may be applied to various parking procedure in which the steering wheel 12 is manipulated.

0097The present invention may be applied to a parking assistor that includes a camera that is attached to a front portion of the vehicle 2. In a corresponding assisted parking procedure, the vehicle 2 is moved forward.

0098The present invention may be applied to a system that obtains data needed for an assisted parking procedure from an external source of the vehicle 2. In this case, the parking procedure is performed in accordance with the external data.

0099Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.

0100A parking assistor displays an image of a rear view from a vehicle, which is acquired by a camera, on a display located in a passenger compartment, thus assisting in a parking procedure. The parking procedure assisted by the parking assistor is, for example, a parallel parking procedure in which the rotating direction of the steering wheel must be switched. An assumed path along which the vehicle is moved during the parking procedure is determined in accordance with the steering angle of the steering wheel when the parking procedure is started. In the parking procedure, the display indicates a steering information that informs the driver of a timing at which the rotating direction of the steering wheel must be switched, in accordance with the assumed path.