Control device for power-assisted bicycle

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a control device for an electrically assisted bicycle, and is particularly suitable for driving the electrically assisted bicycle with a driving sensation similar to that of a bicycle not provided with the electrically assisted bicycle (hereinafter referred to as "ordinary bicycle"). Regarding the control device of.

【0002】

[Conventional technology]

An electric auxiliary bicycle equipped with a human-powered drive system for transmitting the force applied to the pedals by human power, that is, the pedaling force, and a motor drive system that can add auxiliary power to the human-powered drive system according to the pedaling force. Are known. This electrically assisted bicycle is configured to assist human power with a motor output corresponding to the pedaling force and the pedal rotation speed, and when the pedaling force increases, the motor output increases and the human power is reduced. That is, the motor output is a pedal force proportional output.

【0003】

It is also conceivable to generate a motor output so that the weight difference between the electrically assisted bicycle and the ordinary bicycle can be assisted. For example, Japanese Patent Application Laid-Open No. 8-127386 proposes an electrically assisted bicycle in which the weight difference from a normal bicycle is assisted by a motor to reduce the burden on a person during hand-pushed running.

【0004】

[Problems to be Solved by the Invention]

As described above, since the motor output of the conventional electric auxiliary bicycle is proportional to the pedaling force, the pedaling force that periodically changes in magnitude following the pedal rotation is assisted in the direction of amplifying this periodic change. Powered. Therefore, although the burden on the person can be reduced by the auxiliary power, the vehicle speed tends to fluctuate periodically.

【0005】

On the other hand, if the weight difference of the bicycle is covered by the auxiliary power without considering the pedaling force as described in the above-mentioned publication, the periodic fluctuation of the vehicle speed does not occur. However, conventionally, it has not been considered to give auxiliary power without considering the pedaling force even during riding, and it has been limited to only partial use during hand-pushed driving. Therefore, when the traveling on the inclined road surface is taken into consideration, other auxiliary control means such as an inclined sensor is required.

【0006】

In view of the above problems, an object of the present invention is to provide a control device for an electrically assisted bicycle that can be driven with the same driving feeling as a normal bicycle on both slopes and flat roads without amplifying periodic fluctuations in pedaling force. To provide.

【0007】

[Means for solving problems]

In order to achieve the above object, the present invention provides an electric auxiliary bicycle including a human-powered drive system for transmitting a human-powered driving force to the rear wheels and a motor drive system for transmitting the driving force by a motor to the rear wheels. In the control device, the first auxiliary power generating means for generating the first driving force according to the actual running resistance of the vehicle in the motor driving system and the second driving force corresponding to the pedaling force and the crankshaft rotation speed are generated in the motor driving system. The second auxiliary power generating means to be generated in the above, the driving state determining means for discriminating the driving state of the vehicle, and the control to generate the first driving force and the second driving force selectively or in combination according to the driving state. The first feature is that it is equipped with means.

【0008】

The present invention also relates to a control device for an electrically assisted bicycle including a human-powered drive system for transmitting a human-powered driving force to the rear wheels and a motor drive system for transmitting the driving force of a motor to the rear wheels. A running resistance detecting means for detecting the actual running resistance, a first auxiliary power generating means for generating a first driving force corresponding to the actual running resistance in the motor drive system, and a second means for generating a pedaling force and a crankshaft rotation speed. It is provided with a second auxiliary power generating means for generating a driving force in the motor drive system and a discriminating means for determining the inclined state of the road surface based on the actual running resistance, and it is determined that the ground is flat based on the inclined state. In this case, the second feature is that only the first driving force and the second driving force, or the second driving force are selectively generated.

【0009】

Further, in the present invention, when the driving state determination means determines that the driving state is the start of rowing of a vehicle, the present invention selectively selects only the first driving force and the second driving force, or the second driving force. The third feature is that the control means is configured so as to generate it.

【0010】

Further, the present invention relates to a control device for an electrically assisted bicycle including a human-powered drive system for transmitting a human-powered driving force to the rear wheels and a motor drive system for transmitting the motor-driven driving force to the rear wheels. A first auxiliary power generating means that generates a first driving force according to the actual running resistance in the motor drive system, and a second auxiliary force that generates a second driving force according to the pedaling force and the crankshaft rotation speed in the motor drive system. The fourth feature is that the power generating means and the control means for adding the first driving force and the second driving force to obtain the driving force of the motor drive system are provided.

【0011】

According to the above characteristics, the first auxiliary power is generated so as to reduce the resistance (actual running resistance) actually received by the electric bicycle during running, and the second auxiliary power corresponding to the pedaling force is generated. Then, these auxiliary powers are used properly according to the operating state.

【0012】

In particular, according to the second feature, the first and second auxiliary powers are used properly according to the inclined state of the road surface, and an appropriate auxiliary power can be given according to the inclined state. Further, according to the third feature, the first and second auxiliary powers are used properly at the beginning of rowing of the vehicle. Further, according to the fourth feature, auxiliary power can be satisfactorily generated even in a region where the traveling resistance is low.

【0013】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a side view of an electrically assisted bicycle having a control device according to an embodiment of the present invention. The body frame 1 of the electric auxiliary bicycle includes a head pipe 2 located in front of the vehicle body, a down pipe 3 extending rearward from the head pipe 2, a rear fork 4 connected to the down pipe 3 and extending rearward, and a down pipe 3. It is equipped with a seat post 5 that rises upward from the bottom edge of the.

【0014】

The front fork 6 is rotatably supported by the head pipe 2. A front wheel 7 is pivotally supported at the lower end of the front fork 6, and a steering handle 8 is attached to the upper end of the front fork 6. The steering handle 8 is provided with a brake lever 9, and the cable 10 pulled out from the brake lever 9 is connected to the front wheel brake 11 fixed to the front fork 6. Similarly, a brake lever for the rear wheel brake is also provided on the steering handle 8, but the illustration is omitted. Further, the brake lever 9 is provided with a brake sensor (not shown) that detects that the brake lever 9 has been operated.

【0015】

A pair of left and right stays 12 connected to the upper end of the seat post 5 extend rearwardly and are connected to the rear fork 4 near the lower end. A rear wheel 13 is supported by a member formed by connecting the rear fork 4 and the stay 12, and a motor 14 as an auxiliary power source is provided coaxially with the hub of the rear wheel 13 by being supported by the member. As the motor 14, a three-phase brushless motor having high torque and low friction is preferable. The specific structure and control of the motor 14 will be described later.

【0016】

A support shaft 16 having a seat 15 at the upper end is mounted on the seat post 5 so that the height of the seat 15 can be adjusted. Below the seat 15, a battery 17 that supplies power to the motor 14 is provided between the seat post 5 and the rear wheels 13. The battery 17 is held by a bracket 18 that is fixed to the seat post 5. The bracket 18 is provided with a power feeding unit 19, and the power feeding unit 19 is connected to the motor 14 by an electric wire (not shown) and is connected to an electrode of the battery 17. The upper portion of the battery 17 is supported by the seat post 5 with a fastener consisting of a band 20 and a buckle metal fitting 21.

【0017】

A crankshaft 22 extending to the left and right of the vehicle body is supported at the intersection of the down pipe 3 and the seatpost 5, and a pedal 24 is coupled to the crankshaft 22 via the crank 23. A drive sprocket 25 is connected to the crankshaft 22 via a pedal force sensor (not shown), and the pedal effort applied to the pedal 24 is transmitted to the drive sprocket 25 via the pedal force sensor.

【0018】

A chain 27 is hung between the drive sprocket 25 and the driven sprocket 26 provided on the hub of the rear wheel 13. The tension side of the chain 27 and the drive sprocket 25 are covered with the chain cover 28. The crankshaft 22 is provided with a rotation sensor for the crankshaft 22 (not shown). As the rotation sensor, a known one such as a sensor used for detecting the crankshaft rotation of an automobile engine can be used.

【0019】

Subsequently, the pedaling force detecting device mounted on the crankshaft 22 will be described. FIG. 18 is a cross-sectional view around the crankshaft 22, and FIG. 19 is a view taken along the line AA of FIG. Ball bearings 102L and 102R are inserted between the caps 101L and 101R screwed into both ends of the support pipe 100 fixed to the down pipe 3 and the steps formed on the crankshaft 22, respectively, and the crankshaft 22 is inserted. It can be rotated freely.

【0020】

Cranks 23 are fixed to the left and right ends of the crankshaft 22 with nuts 103C that match bolts 103B (only the right side is shown). The inner ring 105 of the one-way clutch 104 is fixed between the crank 23 and the support pipe 100. A drive sprocket 25 is rotatably supported on the outer circumference of the inner ring 105 via a bush 105A. The thrust direction position of the drive sprocket 25 is regulated by the nut 106A and the plate 106B.

【0021】

A lid 107 is integrally provided on the drive sprocket 25, and a transmission plate 108 is arranged in a space surrounded by the drive sprocket 25 and the lid 107. The transmission plate 108 is coaxial with the drive sprocket 25, and is supported so as to allow a planned amount of deviation from each other in the rotation direction about the crankshaft 22.

【0022】

A plurality of (six in this case) windows 109 are bored across the drive sprocket 25 and the transmission play 108, and compression coil springs 110 are housed inside the windows 109, respectively. The compression coil spring 110 acts between the drive sprocket 25 and the transmission plate 108 to generate drag against the displacement when the displacement occurs in the rotational direction.

【0023】

A ratchet tooth 111 as an outer ring of the one-way clutch 104 is formed on the inner circumference of the hub of the transmission plate 108, and the ratchet tooth 111 is supported by the inner ring 105 and urged by a spring 112 in the radial direction. Engage with claw 113. The one-way clutch 104 is provided with a dust-proof cover 114.

【0024】

The transmission plate 108 is provided with a locking hole 116 in which a protrusion 115 for pedal force transmission fixed to the pedal force transmission ring 124 is engaged. The drive sprocket 25 is provided with a window 117 for engaging the protrusion 115 with the locking hole 116, and the protrusion 115 penetrates the window 117 and fits into the locking hole 116. Will be done.

【0025】

A plurality of small windows (three in this case) different from the window 109 are bored across the drive sprocket 25 and the transmission plate 108, and the compression coil spring 118 is housed inside each of the small windows. .. The compression coil spring 118 is arranged so as to urge the transmission plate 108 toward its rotational direction 119. That is, it acts in the direction of absorbing the backlash of the joint portion between the drive sprocket 25 and the transmission plate 108, and functions so that the displacement of the transmission plate 108 is transmitted to the drive sprocket 25 with good responsiveness.

【0026】

The sensor portion (treading force sensor) 47 of the treading force detection device is mounted on the drive sprocket 25 near the vehicle body, that is, on the down pipe 3 side. The tread force sensor 47 has an outer ring 120 fixed to the drive sprocket 25, and a sensor body 121 rotatably provided with respect to the outer ring 120 to form a magnetic circuit.

【0027】

The outer ring 120 is made of an electrically insulating material and is secured to the drive sprocket 25 with bolts (not shown). A cover 122 is provided on the drive sprocket 25 side of the outer ring 120, and is fixed to the outer ring 120 by a set screw 123.

【0028】

FIG. 20 is an enlarged cross-sectional view of the sensor body 121. A coil 125 is provided concentrically with the crankshaft 22, and a pair of cores 126A and 126B are provided on both sides of the coil 125 in the axial direction and projecting in the outer peripheral direction of the coil 125. Further, a cyclic first derivative 127 and a second derivative 128 are provided between the cores 126A and 126B. The first derivative 127 and the second derivative 128 can be displaced from each other in the circumferential direction according to the pedaling force transmitted from the pedaling force transmission ring 124, and due to this displacement, they overlap each other in the portion between the cores 126A and 126B. The amount is configured to vary. As a result, when the coil 125 is energized, the magnetic flux of the magnetic circuit including the core 126A, 126B and the core collar 129, and the first derivative 127 and the second derivative 128 changes according to the pedaling force. Therefore, it is possible to detect the pedal effort by detecting the change in the inductance of the coil 125, which is a function of this magnetic flux. In FIG. 19, reference numerals 130 and 131 are support members of the sensor body 121, reference numeral 132 is a bearing, and reference numeral 133 is a lead wire drawn from the coil 125.

【0029】

The pedaling force detection device is described in detail in the specification of the applicant's prior application (Japanese Patent Application No. 11-251870 (reference number A99-1026)). The pedaling force detecting device is not limited to the above-mentioned one, and a known one can be appropriately selected and used.

【0030】

FIG. 3 is a cross-sectional view of the motor 14. A cylinder 30 incorporating a transmission is supported by a shaft 31 on a plate 29 projecting rearward from a joint at the rear end of the rear fork 4 and the lower end of the stay 12. A wheel hub 32 is fitted on the outer circumference of the cylinder 30. The wheel hub 32 is an annular body having an inner cylinder and an outer cylinder, and the inner peripheral surface of the inner cylinder abuts on the outer circumference of the cylinder 30. A connecting plate 33 overhanging from the cylinder 30 is fixed to the side surface of the wheel hub 32 by bolts 34. Neodymium magnets 35 forming the rotor side magnetic poles of the motor 14 are arranged at predetermined intervals on the inner circumference of the outer cylinder of the wheel hub 32. That is, the outer cylinder constitutes a rotor core holding the magnet 35.

【0031】

A bearing 36 is fitted on the outer circumference of the inner cylinder of the wheel hub 32, and a stator support plate 37 is fitted on the outer circumference of the bearing 36. The stator 38 is arranged on the outer circumference of the stator support plate 37 and is attached by bolts 40. The stator 38 is arranged so as to have a predetermined gap with the outer cylinder of the rotor core, that is, the wheel hub 32, and the three-phase coil 39 is wound around the stator 38.

【0032】

A magnetic pole sensor 41 composed of Hall elements is provided on the side surface of the stator support plate 37. The magnetic pole sensor 41 senses a change in magnetic flux when a magnet 42 protruding from the wheel hub 32 passes, and outputs a position signal of the wheel hub 32 as a rotor. The magnetic pole sensors 41 are provided at three locations corresponding to each phase of the motor 14.

【0033】

Further, on the side surface of the stator support plate 37, a control board 43 for controlling energization of the three-phase coil 39 by a position signal from the magnetic pole sensor 41 is provided, and a CPU, FET, etc. are provided on the control board 43. Control element is installed. The control board 43 can be integrated with the mounting board for the magnetic pole sensor 41.

【0034】

Spokes 44 connected to the rim of the rear wheel (not shown) are fixed to the outer circumference of the wheel hub 32. Further, the bracket 46 is fixed by the bolt 45 on the side of the stator support plate 37 opposite to the side on which the control board 43 or the like is mounted, and the bracket 46 is connected to the plate 29 of the vehicle body frame by a bolt (not shown). To.

【0035】

In this way, the three-phase brushless motor 14 consisting of the stator and rotor arranged coaxially with the shaft 31 of the rear wheel 13 is provided, and the auxiliary power added to the human power transmitted by the chain 17 and the driven sprocket 26 is provided. appear.

【0036】

Subsequently, energization control, that is, output control for the motor 14 will be described. FIG. 4 is a diagram showing a mode in which auxiliary power is generated in the assumed running path, and the horizontal axis is the time axis. Here, it is assumed that the road surface starts from a flat road, goes uphill and downhill, and then runs on the flat road again. In this assumed running road, the speed is gradually increased from a flat road, and after approaching an uphill, a running pattern for running at a constant speed is set. In the figure, the driving force shown by the curve is related to the conventional control in which the auxiliary power is generated in proportion to the pedaling force, and the small curve shows the driving force (human power) Ph by the pedaling force Ta, which is in phase with this curve. The large curve shows the auxiliary power Pm by the motor. As can be understood from this figure, in the conventional method in which the human power Ph and the auxiliary power Pm are controlled to have a ratio of 1: 1, the auxiliary power Pm increases on the uphill, but the human power Ph is also at a high level. ..

【0037】

On the other hand, in the present embodiment, the driving force corresponding to the predetermined driving force, that is, the driving force corresponding to the flat ground running resistance of the light vehicle is controlled so as to be shared by the person on any of the flat road, the uphill and the downhill road surfaces. Specifically, of the running resistance Ra generated by running, only the resistance when driving a relatively light vehicle among ordinary bicycles, which is generally called a light bicycle, on a flat road is manually borne, and the rest. Is assisted by the output of the motor 14. As a result, the driver can drive on a flat road as if he / she is driving a light vehicle on any road surface. In FIG. 4, the motor torque is generated so as to give the auxiliary power Pm to the resistance Ra actually generated during traveling. At this time, the motor torque is determined so that (Ra-Pm) becomes a predetermined value. That is, the driver can drive the bicycle with a predetermined pedaling force Ta corresponding to the flat ground running resistance of the light vehicle.

【0038】

The output control will be described in more detail below. However, the above content is a basic concept of output control in the present embodiment, and the specific control described below includes various modifications.

【0039】

FIG. 1 is a functional block diagram of a main part of a control device that controls the output of the motor 14 according to an actual running resistance, and a calculation unit, a storage unit, and the like in this function can be realized by a microcomputer. In the figure, the pedaling force detecting unit 51 detects the pedaling force Ta by the detection signal of the pedaling force sensor 47. The crank rotation speed detection unit 52 detects the crank rotation speed NCR by the detection signal of the crank rotation speed sensor 48. The human power calculation unit 53 calculates the driving force Ph proportional to the pedaling force input from the pedal 24 by using the following equation (Equation 1). Ph = Ta × NCR × k1 ... (Equation 1). However, k1 is a coefficient.

【0040】

The total driving force calculation unit 54 calculates the total driving force Pw by adding the driving force Ph obtained by human power, the motor torque T, and the motor output based on the motor rotation speed Nm. The motor torque T used here is the previous value, that is, the value T-1 stored in the previous value memory 61.

【0041】

The motor rotation speed detection unit 56 detects the motor rotation speed Nm by the detection signal of the motor rotation sensor 49. The vehicle speed detection unit 57 detects the vehicle speed V by the detection signal of the vehicle speed sensor 50. The magnetic pole sensor 41 can be used as the motor rotation sensor 49 and the vehicle speed sensor 50.

【0042】

The vehicle speed memory 58 stores the previously detected value V-1 of the vehicle speed V. The vehicle speed change amount calculation unit 59 calculates the difference ΔV between the previous value V-1 and the current value V of the vehicle speed V. The standard running resistance calculation unit 60 searches the map for the flat ground running resistance Rr of a normal bicycle according to the vehicle speed V.

【0043】

The traveling resistance calculation unit 62 searches a map for each vehicle speed V based on the total driving force Pw and the vehicle speed change amount ΔV, and calculates the actual traveling resistance Ra. The map for obtaining the actual running resistance Ra will be described later. The traveling resistance calculation unit 62 may use the integrated value of the total driving force Pw instead of the total driving force Pw. That is, the total driving force integrating unit 55 can be provided and its output can be used. The total driving force integrating unit 55 integrates the total driving force Pw for each scheduled time or for each scheduled period to obtain the integrated value P · h. For example, the integrated value P · h of the total driving force Pw during one rotation of the crankshaft 22 is obtained.

【0044】

The auxiliary power calculation unit 63 calculates the auxiliary power Pm by the motor 14 by subtracting the flat ground running resistance Rr of a normal bicycle from the actual running resistance Ra. The motor torque calculation unit 64 calculates the motor torque T commanded to the motor 14 based on the motor rotation speed Nm and the auxiliary power Pm. The motor torque T is obtained by searching a map set in advance as a function of the motor rotation speed Nm and the auxiliary power Pm. The calculated motor torque T is output to the control unit of the motor 14 and stored in the previous value memory 61.

【0045】

As described above, according to the above control device, the actual running resistance Ra is obtained by the change in vehicle speed corresponding to the input energy while pedaling the pedal 24, and among the actual running resistance Ra, when the normal bicycle is running on flat ground. The amount excluding the running resistance Rr is the output of the motor 14 and is added to human power.

【0046】

FIG. 5 is a block diagram showing the main functions (No. 2) of the control device. This control device is provided with a road surface inclination determining means, and can increase or decrease the auxiliary power Pm according to the road surface inclination. In FIG. 5, the assist vehicle flat ground running resistance calculation unit 65 is provided, and the assist vehicle flat ground running resistance R1 is calculated by searching a predetermined map based on the vehicle speed V. The road surface inclination determination unit 66 is based on the actual running resistance Ra calculated by the running resistance calculation unit 62 and the assist vehicle flat ground running resistance R1. If the actual running resistance Ra is larger than the flat ground running resistance R1 than planned, the road surface inclination determination unit 66 is uphill. If it is judged that the vehicle is running and the actual running resistance Ra is smaller than the planned running resistance R1 on flat ground, it is judged that the vehicle is running downhill. At the start of the uphill, the timer 67 is activated, and the auxiliary force increasing unit 68 is urged until the measurement by the timer 67 is completed. On the other hand, at the start of the downhill, the timer 69 is activated, and the auxiliary power reduction unit 70 is urged until the measurement by the timer 69 is completed.

【0047】

The auxiliary power increasing unit 68 corrects the coefficient used for calculating the auxiliary power so that the auxiliary power Pm increases, and the auxiliary power reducing unit 70 corrects the coefficient used for calculating the auxiliary power by the auxiliary power Pm. Correct so that it decreases. The auxiliary power calculation unit 63 outputs the auxiliary power Pm corrected according to the road surface inclination according to the corrected coefficients supplied from the auxiliary power increasing unit 68 and the auxiliary power reducing unit 70.

【0048】

FIG. 6 is a diagram showing the timing of determining the auxiliary power. The figure shows the vehicle speed V, pedaling force Ta, auxiliary power Pm by the motor, and the detection / calculation timing of these. The detection output of each sensor is read from the time when the minimum value of the pedaling force Ta is detected until the next minimum value of the pedaling force Ta is reached. Then, when the pedaling force Ta reaches the minimum value, the calculation of the next auxiliary power Pm is started based on the detected value of each sensor at that time. Further, when the pedaling force Ta becomes the minimum value, the vehicle speed V is detected and the difference ΔV from the previous vehicle speed is calculated. For example, at timings t1, t2, and t3, the auxiliary power Pm is calculated and the vehicle speed difference (VV-1) is calculated. Further, the energization duty for obtaining the auxiliary power Pm whose calculation is started at the timings t1, t2, and t3 is indicated by the timings t1', t2', and t3', respectively.

【0049】

FIG. 7 is an output control circuit diagram of the motor 14, and FIG. 8 is a diagram showing an energization timing and an energization duty. In FIG. 7, the full-wave rectifier 71 has FETs (generally solid switching elements) 71a, 71b, 71c, 71d, 7e, 71f connected to a three-phase stator coil 39, and the FETs 71a to 71f are drivers. Energization is controlled by 72. The energization duty is set by the duty setting unit 73 based on the instruction supplied from the motor torque calculation unit 64 and input to the driver 72.

【0050】

At the drive timing for applying the auxiliary power Pm, the duty setting unit 73 supplies the current-carrying duty to the driver 72, and the driver 72 urges the FETs 71a to 71f according to the current-carrying duty and supplies the current from the battery 17. On the other hand, when the regenerative output is generated, the energization duty is supplied from the duty setting unit 73 to the driver 72 at the regenerative timing 180 degrees deviated from the drive timing by the electric angle, and the driver 72 follows the energization duty and receives FET71a ~. Equip 71f. When the FETs 71a to 71f are urged at the regeneration timing, the current generated in the stator coil 39 is rectified by the FETs 71a to 71f and supplied to the battery 17.

【0051】

The torque determination unit 74 determines whether the drive timing or the regeneration timing is based on the required motor torque T supplied from the motor torque calculation unit 64. When the required value T of the motor torque is positive, the energization timing is set in the drive timing, and when the required value T of the motor torque is negative, the energization timing is set in the regeneration timing.

【0052】

In FIG. 8, FETs 71a to 71f are urged by setting the energization angle to an electric angle of 120 degrees. The figure shows the energization timing at the drive timing, and at the regeneration timing, the high-side FETs 71a, 71c, 71e are shifted by 180 degrees by the electric angle from this drive timing.

【0053】

9 and 10 are flowcharts of the main parts of the process for generating auxiliary power according to the actual running resistance. In the figure, in step S1, the vehicle speed V is calculated based on the detection output of the motor rotation sensor 49. In step S2, the flat ground running resistance R1 of the electrically assisted bicycle (hereinafter referred to as assisted vehicle) and the flat ground running resistance Rr of the normal bicycle (light vehicle) are calculated based on the vehicle speed V. For example, when a light vehicle with a vehicle weight of 12 kg is driven by a person with a weight of 55 kg, the standard flat ground driving resistance Rr is used, and when an assist vehicle with a vehicle weight of 26 kg is driven by a person with a weight of 65 kg, the flat ground driving resistance R1 To do.

【0054】

These flat ground running resistances R1 and Rr can be searched from a preset map. FIG. 11 is a map showing an example of the relationship between the vehicle speed V and the flat ground running resistances R1 and Rr. In the figure, the flat ground running resistance R1 of the assisted vehicle and the flat ground running resistance Rr of a normal bicycle are shown as functions of the vehicle speed V, respectively. By applying the vehicle speed V to this map, it is possible to obtain the flat ground running resistance R1 of the assisted vehicle and the flat ground running resistance Rr of a normal bicycle.

【0055】

Returning to FIG. 9, in step S3, the difference (VV-1) between the previously detected vehicle speed V-1 and the vehicle speed V detected this time is calculated to obtain the vehicle speed change amount ΔV (deceleration when the value is negative). In step S4, the pedaling force Ta and the crank rotation speed NCR are detected by the detection outputs of the pedaling force sensor 47 and the crank rotation speed sensor 48, respectively. In step S5, the output proportional to the pedaling force, that is, the motor torque T0, which is a function of the pedaling force Ta and the crank rotation speed NCR, is calculated by the following equation (Equation 2). Motor torque T0 = f (Ta, NCR) ... (Equation 2).

【0056】

In step S6, the output of the motor rotation sensor 49, that is, the rotation speed Nm of the motor 14 is detected. In step S7, the previous motor torque T-1 is read from the previous value memory 61. In step S8, the total of the total driving force Pw, that is, the human power Ph and the auxiliary power Pm-1 is calculated by the following equation (Equation 3). Driving force Pw = (Ta × NCR × k1) + (T-1 × Nm × k2) ... (Equation 3). Here, k1 and k2 are coefficients.

【0057】

In step S9, the actual running resistance Ra, which is a function of the driving force Pw, the speed change amount ΔV, and the vehicle speed V, is calculated by the following equation (Equation 4). Actual running resistance Ra = f (Pw, ΔV, V) ... (Equation 5). Specifically, for the calculation of the actual running resistance Ra, a relational map of the driving force Pw, the speed change amount ΔV and the actual running resistance Ra is prepared for each vehicle speed V (for example, every 5 km / hour) in a plurality of stages. You can search and find this map. FIG. 12 is an example of a map in which the relationship between the driving force Pw, the speed change amount ΔV, and the actual running resistance Ra is used as the parameter of the speed change amount ΔV. In the figure, the flat ground running resistance R1 of the assisted vehicle and the flat ground running resistance Rr of a normal bicycle are shown as functions of the vehicle speed V, respectively. Such a map is prepared for each vehicle speed V in multiple stages. As described above, instead of the driving force Pw, one cycle, that is, the integrated value P · h of the total driving force for each rotation of the crankshaft 22 may be used.

【0058】

In step S10, the slope of the road surface is determined, that is, whether it is an uphill or a downhill. This judgment can be made by the value of the ratio of the actual running resistance Ra and the flat ground running resistance R1 of the assist vehicle. For example, if the ratio value (Ra / R1) is "5" or more, it is judged as an uphill, if it is "-1", it is judged as a downhill, and if it is an intermediate value between these, it is judged as a flat land.

【0059】

If it is determined to be an uphill, proceed to step S11 and clear the flag F1 indicating that the slope is downhill. In step S12, it is determined whether or not the flag F0 indicating the uphill is set, and if this is affirmative, the process proceeds to step S23 (FIG. 10). If step S12 is negative, set the coefficient K to "1.2" in step S13. By increasing the coefficient K, as will be described later, the auxiliary power Pm becomes smaller, and the driver can realize that he / she is approaching an uphill.

【0060】

In step S14, the counter value n is incremented. In step S15, it is determined whether or not the counter value n has reached 5. When the counter value n becomes "5", the counter value n is cleared in step S16, the flag F0 is cleared, and the inclination correction value calculation process (FIGS. 15 and 16 will be described later) in step S23 (FIG. 10). )I do. If the counter value n is not "5", the process proceeds to step S24 (FIG. 10).

【0061】

On the other hand, if it is determined that the slope is downhill, the process proceeds to step S17, and the flag F0 indicating that the slope is uphill is cleared. In step S18, it is determined whether or not the flag F1 indicating the downhill is set, and if this is affirmative, the process proceeds to step S23 (FIG. 10). If step S18 is negative, set the coefficient K to "0.8". By reducing the coefficient K, as will be described later, the auxiliary power Pm becomes large, and the driver can realize that the vehicle has gone downhill. In step S20, the counter value m is incremented. In step S21, it is determined whether or not the counter value m has reached 3. When the counter value m becomes "3", the counter value m is cleared in step S22, the flag F1 is cleared, and the process proceeds to step S23. If the counter value m is not "3", the process proceeds to step S24 (FIG. 10). When it is determined in step S10 that the ground is flat, the process proceeds to step S24 without processing the coefficients K, counter values m, n, and the like.

【0062】

In FIG. 10, in step S24, it is determined whether or not the brake switch is on. If the brake switch is on, the coefficient K is multiplied by the constant "1.2" in step S25 to proceed to step S26. By multiplying this coefficient K, the regenerative output becomes large as described later. If the brake switch is not on, skip step S25 and proceed to step S26. In step S26, the flat ground running resistance Rr of a normal bicycle is multiplied by a coefficient K. In step S27, the auxiliary power Pm is calculated by the following equation (Equation 6). Auxiliary power Pm = Ra-Rr ... (Equation 6).

【0063】

As can be understood from the above equation 6, the auxiliary power Pm becomes small when the flat ground running resistance Rr of a normal bicycle is large, and becomes large when the flat ground running resistance Rr is small. Since the coefficient K is multiplied by the flat ground running resistance Rr in step S26, the auxiliary power Pm changes according to this coefficient K. Therefore, when it is determined that the vehicle is uphill and the coefficient K is set to "1.2" (step S13), the auxiliary power Pm becomes small until the counter n reaches the planned value "5", and the driver Feels an increase in load. On the other hand, when it is determined that the vehicle is downhill and the coefficient K is set to "0.8" (step S19), the auxiliary power Pm increases until the counter m reaches the planned value "3", and the driver Feels a decrease in load.

【0064】

Further, when the coefficient K is increased in step S25, the regenerative output is increased for the following reason. That is, in a situation where braking is applied, the total driving force Pw is small, and the actual running resistance Ra is also a negative value. Therefore, by increasing the coefficient K and increasing the traveling resistance Rr, the negative value of the actual traveling resistance Ra becomes larger in the process of step S27, and the regenerative output increases. In this way, when the brake is operated, the brake can be effectively braked by the regenerative braking by the motor 14.

【0065】

In step S28, the motor torque T, which is a function of the auxiliary power Pm and the motor rotation speed Nm, is calculated by the following equation (Equation 7). Motor torque T = f (Pm, Nm) ... (Equation 7).

【0066】

The motor torque T may be changed as follows. In step S29, the motor torque T0 proportional to the pedal effort is added to the motor torque T. With this change, light driving is possible in the entire traveling area.

【0067】

In step S30, the energization timing of the motor 14 is controlled. If the calculated motor torque T is positive, the control element (FET) of the full-wave rectifier 71 that controls the motor 14 is urged at the timing of driving. On the other hand, if the calculated motor torque T is negative, the control element (FET) that controls the motor 14 is urged at the timing for regeneration. That is, the timing is set so that the electric angle deviates by 180 degrees with respect to the driving time. In step S31, the energization duty is determined based on the absolute value of the motor torque T.

【0068】

In step S32, when it is determined that the vehicle is downhill, it is determined whether or not the vehicle speed V is the planned low speed (for example, 5 km / hour or less). If this judgment is negative, the process proceeds to step S33 and the settings of steps S26 and S27 are output to the motor 14. That is, even if it is determined to be downhill, if it is determined to be in a low speed state such as pushing, the energization control of the motor 14 is not performed, and therefore the regenerative control output is not generated.

【0069】

Further, step S29 can be transformed as follows. In the modified example of FIG. 13, in step S34, it is determined whether or not the ground is flat, and in the case of flat ground, the motor torque T0 proportional to the pedal effort is added (step S35). Further, instead of step S35, the motor torque T can be replaced with the motor torque T0 proportional to the pedal effort as in step S36. As a result, on flat ground, it is possible to obtain an auxiliary power Pm in proportion to the pedal effort and operate the vehicle.

【0070】

Further, step S29 can be transformed as follows. In the modified example of FIG. 14, in step S37, it is determined whether or not the vehicle speed V is the planned low speed (for example, 5 km / hour or less), and if it is determined to be low speed, the motor torque T0 corresponding to the pedal effort is determined. Is added (step S38). Further, instead of step S38, the motor torque T is replaced with the motor torque T0 proportional to the pedal effort as in step S39. As a result, for example, at the beginning of rowing, auxiliary power is obtained by the motor torque T proportional to the pedaling force.

【0071】

The functions of step S29 and its modified example are shown in a functional block diagram in FIG. In the figure, the motor torque calculation unit 64A calculates the motor torque T as a function of the auxiliary power Pm by the motor 14 and the motor rotation speed Nm, as in the calculation unit 64 described with reference to FIG. Further, the motor torque calculation unit 64A calculates the motor torque T0 as a function of the driving force Ph proportional to the pedaling force detected by the human power calculation unit 53 and the crank rotation speed NCR. The driving state determination unit 75 determines the driving state of the vehicle based on the actual running resistance Ra, the assisted vehicle flat ground running resistance R1, the vehicle speed V, etc., and depending on the driving state, the added value of the motor torques T and T0 or the motor torque. Command T0 to motor 14.

【0072】

Subsequently, a specific example of the step S23 will be described. In step S23, the coefficient K is corrected to match the slope of the track. First, an example of uphill correction is shown. FIG. 15 is a diagram showing the value of the coefficient K corresponding to the vehicle speed V when traveling uphill. Figure (a) shows an example in which the amount of change in vehicle speed per second is less than 3 km / hour, and Figure (b) shows an example in which the amount of change in vehicle speed is 3 km / hour or more. The initial value of the coefficient K is "1.0". In FIG. 15 (a), when the vehicle speed V is low (for example, 5 km / hour or less) at the beginning of rowing, the coefficient K is reduced and the auxiliary power Pm is increased. Then, after the vehicle speed V has increased, the coefficient K is returned to the initial value.

【0073】

In FIG. 15 (b), when the vehicle speed V is low (for example, 5 km / hour or 10 km / hour), the coefficient K is decreased and the auxiliary power Pm is increased. Then, as the vehicle speed V increases, the coefficient K is gradually returned to the initial value. That is, when accelerating, the auxiliary power Pm is not suddenly reduced, but is maintained at a large value until the vehicle speed V increases to some extent (for example, 20 km / hour). The correction example for uphill running can also be applied to running on flat terrain.

【0074】

Next, an example of downhill correction is shown. FIG. 16 is a diagram showing the value of the coefficient K corresponding to the vehicle speed V when traveling downhill. The initial value of the coefficient K is "1.0". In FIG. 16, when the vehicle speed V is low (for example, 15 km / hour or less), such as when rowing starts on a downhill, the coefficient K is reduced to reduce the regenerative output. Then, when the vehicle speed V increases, for example, from 15 km / hour to 20 km / hour, the coefficient K is increased in proportion to the increase in the vehicle speed V, and the regenerative output is gradually increased. When the vehicle speed V further increases, the coefficient K is rapidly increased (for example, in a quadratic curve) until the vehicle speed V increases to some extent (for example, 25 km / hour). As a result, the regenerative output increases sharply and the vehicle speed V is rapidly limited.

【0075】

[Effect of the invention]

As is clear from the above description, according to the inventions of claims 1 to 4, in a state where the first auxiliary power corresponding to the actual running resistance is applied, the second auxiliary power based on the pedal effort is applied according to the driving state. Appropriate control can be performed, such as using them together as appropriate or switching to operation with only the second auxiliary power. Therefore, auxiliary power can be satisfactorily generated even in a region where the actual running resistance is low.

[Simple explanation of drawings]

[Figure 1]

It is a block diagram which shows the main part function of the control device which concerns on one Embodiment of this invention.

[Figure 2]

It is a side view of the electric auxiliary bicycle which has the control device which concerns on one Embodiment of this invention.

[Fig. 3]

It is sectional drawing of a motor.

[Fig. 4]

It is a figure which shows the relationship between the change of the road surface condition and the change of a driving force.

[Fig. 5]

It is a block diagram which shows the control function of auxiliary power at the start of an inclined surface.

[Fig. 6]

It is a timing chart which shows the timing of auxiliary power determination by vehicle speed and pedaling force.

[Fig. 7]

It is a control circuit diagram of a motor.

[Fig. 8]

It is a timing chart which shows the control timing of a motor.

[Fig. 9]

This is the main flow chart (1) of the process that generates auxiliary power according to the actual running resistance.

[Fig. 10]

This is the main flow chart (Part 2) of the process that generates auxiliary power according to the actual running resistance.

[Fig. 11]

It is a map showing the relationship between vehicle speed and running resistance on flat ground.

[Fig. 12]

It is a figure which shows an example of the map which searches the actual running resistance by the amount of change in vehicle speed and the driving force.

[Fig. 13]

It is a flowchart which concerns on the modification of step S29.

[Fig. 14]

It is a flowchart which concerns on another modification of step S29.

[Fig. 15]

It is a figure (No. 1) which shows the relationship between the correction coefficient of auxiliary power and the vehicle speed.

[Fig. 16]

It is a figure (2) which shows the relationship between the correction coefficient of auxiliary power and the vehicle speed.

[Fig. 17]

It is a block diagram which shows the function for properly using the auxiliary power proportional to the pedaling force and the auxiliary power according to the actual running resistance.

[Fig. 18]

It is sectional drawing of the main part of the human power drive device which incorporated the tread force detection device.

[Fig. 19]

It is AA arrow view of FIG.

[Fig. 20]

It is an enlarged sectional view of the pedaling force detection device.

[Explanation of symbols]

1 ... Body frame, 5 ... Seatpost, 8 ... Steering handle, 9 ... Brake lever, 14 ... Motor, 17 ... Battery, 22 ... Crankshaft, 24. .. pedal, 27 ... chain, 32 ... wheel hub, 35 ... magnet, 37 ... stator support plate, 39 ... stator coil, 41 ... magnetic pole sensor, 43 ... board , 47 ... pedal force sensor, 48 ... crank rotation sensor, 49 ... motor rotation sensor, 50 ... vehicle speed sensor, 59 ... vehicle speed change amount calculation unit, 62 ... running resistance calculation unit, 75 ... Operating condition discriminator