Method and system for aligning a stationary vehicle with an artificial horizon

[0001] In this application, priority is claimed to the provisional application US 60 / 463.487, filed April 17, 2003.

[0002] The present invention broadly relates to air suspension systems, in particular it relates to an electronically controlled air suspension system suitable for use in a stationary vehicle for adjusting the air springs of this stationary vehicle to position its chassis substantially in alignment with artificial horizon or some other pre-defined data.

[0003] The present invention finds particular application in connection with the use of larger motor vehicles such as for example motorhomes (RVs), caravans and heavy truck trailers / semitrailers, and it will be described in this document in particular with reference to the said. Nevertheless, it should be understood that such vehicles are simply exemplary structures, and the present invention may have a broader application in connection with the alignment of various structures and vehicles within a wide range. Further examples of such structures and vehicles include tow trucks, military and civilian transport vehicles for the transport of persons, as well as ambulances.

[0004] Many large vehicles, such as motor homes (RVs), caravans, truck trailers / semitrailers and the like, have an air suspension system for adjusting the height of the vehicle chassis relative to the supporting axles in such a way that it is dependent on the load placed in the vehicle to adjust the height of the chassis to suit the driving conditions encountered by that vehicle. These suspension systems usually consist of a number of hydraulic-air suspension members, such as air springs, which support the vehicle chassis above the axles. The height of the air springs is controlled by the input and output of compressed fluid from a suitable source mounted on the vehicle, such as a compressor. Traditionally, one or more intermediate valves are used to facilitate the introduction and discharge of compressed fluid to and from the air springs, and thus adjust the height of the air springs and thus the position of the vehicle chassis relative to the vehicle axis. These types of systems also allow the vehicle chassis to be maintained in an orientation substantially aligned with the axis while the vehicle remains stationary.

- 2 This is done by independently adjusting the height of each of the air springs that support the vehicle chassis on the axles. One of the drawbacks associated with such systems, however, is that the chassis can only be positioned relative to the axis. Therefore, if the axles are positioned in an undesirable orientation, the chassis, although level with respect to the axles, will also be located in such an undesirable orientation.^tion.

[0005] As an alternative concept, many of these vehicles, such as RVs, will also use a number of hydraulic jacks that are lowered to level the RV floor when it is parked and parked. However, in certain situations, the use of hydraulic jacks is not allowed, such as when the RV is parked on an asphalt parking spot, because the jacks can damage asphalt. Therefore, vehicle leveling cannot be performed under such conditions. Another disadvantage is the cost associated with such systems because they use very few standard vehicle components. This means that hydraulic jacks, control valves, hydraulic lines, electronic control unit and user interface as well as other components must be installed on the vehicle, on or above standard components that have already been installed. Therefore, such additional components increase the cost of the vehicle when it is planned to achieve leveling.

[0006] Also in some RVs, existing suspension air springs can be used to adjust the floor height and level the floor, using mercury switches or other controls that will raise and lower some of the air springs to adjust the height of the floor relative to the vehicle axis until until leveling is achieved. Some examples of such hydraulically operated leveling systems for trailers, RVs etc. are disclosed in US Patent Nos. 5,228,704, US 5,465,209, US 5,180,024, US 5,499,845, US 6,431,557 and US 6,428,026. Nevertheless, it will be understood that these systems may be useful in situations where there are changes in load distribution in the chassis of a parked or otherwise immobilized vehicle. However, such systems remain ineffective when leveling the vehicle chassis when the vehicle axles themselves are not in the level orientation.

[0007] The above-mentioned patents disclose numerous suspension leveling and control systems for air springs in vehicles, some of which operate while the vehicle is moving, while others are activated when the vehicle is stationary. Most of these systems use pneumatic springs to adjust the height of the vehicle chassis relative to the axle or support structure of the wheels to obtain a level condition. Many of these systems also require separate control systems that are used in addition to existing suspension components and the pneumatic chassis control system.

[0008] Even for these reasons, it is considered desirable to develop an air suspension system in which these and other disadvantages are eliminated.

Attention is drawn to the disclosure in document JP-04-071918A.

The present invention in one aspect relates to a method of positioning a vehicle chassis in approximate alignment with a certain predetermined data, wherein the vehicle has at least one axle and a hydraulic-pneumatic suspension system, whereas the previously determined data is the default reference plane independent of the distance of the vehicle chassis from axles or wheels, while the hydraulic-pneumatic suspension system includes a number of hydraulic-pneumatic suspension members located between the axle and chassis, a control unit, a source of compressed fluid and an exhaust passage in fluid communication with a certain number of hydraulic-pneumatic suspension members through the control unit, as well as an electronic control unit connected working with the control unit, and the method includes the following steps:

(a) provides no alignment sensor supported on the chassis to send a signal indicating the orientation of the chassis to the electronic control unit;

b) receiving the signal sent by the alignment detector:

c) making a comparison from the alignment sensor with the data assigned to the orientation of a certain predetermined data stored in the electronic control unit as the alignment data;

d) determining which of the right front, left front, left rear, right rear, all front, all rear, all left or all right side is the high position of the vehicle chassis;

(e) determining whether the high position can be lowered sufficiently to bring the vehicle chassis into rough alignment with that predetermined data; and

(f) selective action by a control means to allow fluid communication between the respective one or more hydraulic-pneumatic suspension members and fluid output until the signal from the alignment sensor approximately corresponds to the alignment data.

The invention in a further aspect relates to a control system adapted to position the vehicle chassis in a stationary vehicle in an appropriate alignment with a certain predetermined data, the vehicle comprising axles and wheels, and the predetermined given is a default reference plane independent of the distance of the vehicle chassis from the axle or wheels, while control systems include:

a number of hydraulic-pneumatic suspension members supporting the chassis in an adjustable manner on the axis of a stationary vehicle;

a source of compressed fluid, operatively connected to the members of the hydraulic-pneumatic suspension;

- 4 control unit, operatively connected between the fluid source and the hydraulic-pneumatic suspension members, used to control the flow of compressed fluid to and from the hydraulic-pneumatic suspension members;

alignment sensor supported on the chassis and emitting a signal indicating the orientation of the chassis; and an electronic control unit operatively connected to the control unit and the alignment sensor, the electronic control unit receiving a signal from the alignment sensor and operating in such a way that it performs the following operations:

compares the signal from the alignment sensor with the data assigned to the orientation of the predetermined data and stored in this electronic control unit as the alignment data;

this determines which of the right front, left front, left rear, right rear, all front, all rear, all left or all right side is the high position of the vehicle chassis;

this determines whether this high position can be lowered sufficiently to bring the vehicle chassis into an approximate alignment with the previously determined data; and also selectively actuates the control assembly to adjust the corresponding one or more hydraulic-pneumatic suspension members until the signal from the alignment sensor indicates that the chassis has been approximately aligned with the predetermined data.

[0009] A method of positioning a vehicle chassis is provided in approximate alignment with a predetermined data. The vehicle has an axle and a hydraulic-pneumatic suspension system. This hydraulic-pneumatic suspension system consists of a number of hydraulic-pneumatic suspension members, a control unit, a source of compressed fluid and an outlet passage. The elements of the hydraulic-pneumatic suspension are located between the axle and the chassis of the vehicle. The source of the compressed fluid and the outlet passage are in fluid communication with a number of hydraulic-pneumatic suspension members through the control unit. The vehicle also includes an electronic control unit operatively connected to the control unit. The method includes the steps of providing an alignment sensor supported on the chassis to send a signal indicating the orientation of the chassis to the electronic control unit and to receive the signal sent by the alignment sensor. The next step involves comparing the signal from the alignment sensor with the alignment data stored in the electronic control unit. The next stage involves the selective operation of the control assembly to allow fluid communication to be established between one or more hydraulic-pneumatic suspension members and one of the pressurized fluid source and fluid outlet until the signal from the alignment sensor approximately corresponds to the alignment data.

[0010] A control system adapted to position the vehicle chassis in a stationary vehicle in substantial alignment relative to a certain predetermined data is provided, and it comprises a number of hydraulic-pneumatic suspension members in a regulated manner supporting the chassis on the stationary vehicle axis. The source of compressed fluid is operatively connected to the members of the hydraulic-pneumatic suspension. The control assembly is operatively connected between the fluid source and the hydraulic-pneumatic suspension members to control the flow of compressed fluid to and from the hydraulic-pneumatic suspension members. The alignment sensor is supported on the chassis to send a signal indicating the orientation of the chassis. The electronic control unit is operatively connected to the control unit and the alignment sensor. This electronic control unit is used to receive the signal from the alignment sensor and to selectively actuate the control unit to adjust one or more hydraulic-pneumatic suspension members until the signal from the alignment sensor indicates that the chassis is approximately aligned with the predetermined data.

[0011] A method for positioning a vehicle chassis in a stationary vehicle is provided in an approximate alignment with a certain predetermined data. The vehicle has an axle and a hydraulic-pneumatic suspension system. This hydraulic-pneumatic suspension system includes a number of hydraulic-mechanical suspension members, a control unit, a source of compressed fluid, as well as an outlet passage. The hydraulic-pneumatic suspension members are located between the axle and the chassis of the vehicle. The source of the compressed fluid and the outlet passage are in fluid communication with a number of hydraulic-pneumatic suspension members through the control unit. The vehicle also includes an electronic control unit operatively connected to the control unit. This method includes the steps of providing an alignment sensor supported on the chassis to send a signal indicating the orientation of the chassis to the electronic control unit and to receive the signals sent by this alignment sensor. The next step involves comparing the signal from the alignment sensor with the alignment data stored in the electronic control unit. The next stage involves the selective operation of the control assembly to allow fluid communication between one or more hydraulic-pneumatic suspension members and the compressed fluid source and fluid outlet until the signal from the alignment sensor approximately corresponds to the alignment data.

The present invention relates to an electronic control system for leveling the vehicle chassis, such as a frame, subframe, floor and / or body, for example an RV or motorhome, and uses existing components of the hydraulic-pneumatic suspension of the vehicle's chassis , while avoiding the need to use additional components duplicated at a high cost and additional use of space, to provide the desired leveling effect to the vehicle chassis, especially when the vehicle is stationary.

[0013] Another feature of the invention relates to a leveling system which only requires the addition of an alignment sensor or other level sensing assembly, such as for example an accelerometer, tilt sensor, gyroscope or the like.

The alignment sensor is supported on the vehicle chassis and is operatively connected to an electronic control unit (ECU) which is used to control the chassis suspension in conjunction with the ECU software designed to perform the method of the present invention.

[0014] Another feature of the invention relates to a leveling control system relative to the horizon, aligning the vehicle chassis with a certain artificial horizon or other predetermined data independent of the distance of the vehicle chassis from the axles or wheels, by entering this artificial horizon or the predetermined data into the ECU software.

[0015] A further feature of this invention relates to a locking system via a standard height compensation system to ensure that the ECU automatically disengages the leveling system relative to the horizon in the event of vehicle movement or in the vehicle selecting the gear position in readiness for the subsequent vehicle movement.

[0016] A further aspect of this invention is to enable the system to determine whether individual air springs have a sufficient displacement range to enable the vehicle to reach leveling after deflection or the vehicle orientation is predetermined by the system before attempting to perform proper leveling by introducing or discharging air to or from selected pneumatic springs.

[0017] Another feature of this invention is the ability to adjust the height of individual air springs in a specific order, such as by pre-adjusting for larger ranges of unevenness by adjusting the air springs on one side of the vehicle, after which smaller height deviations can be compensated by adjusting the front one or rear pneumatic spring on the selected side of the vehicle.

[0018] Another advantage of the present invention is to allow the system to initially evacuate air from pneumatic springs on the higher side or at the higher corner of the vehicle after the misalignment detection is detected, before introducing additional compressed fluid into one or more pneumatic springs to lift the bottom hand, as a result, the depletion of compressed fluid resources is limited and the additional work of the vehicle compressor is minimized.

[0019] In summary, this invention relates to a leveling system relative to a certain horizon, and uses most of the features and components of the chassis suspension of a vehicle such as, for example, an RV, caravan or heavy truck trailer / semi-trailer, by adding a horizontal alignment detection unit and by programming the ECU using an artificial horizon or other predetermined data. This arrangement is adapted to make

- 7 adjustment of the vehicle chassis orientation to obtain alignment with the artificial horizon, regardless of the position of the vehicle axis.

The method of this invention may further include the steps of providing displacement range end data indicating the extreme orientation of the chassis, storing this displacement range end data in the electronic control unit, receiving a signal from the alignment sensor indicating the orientation of the chassis, and comparing the signal with displacement range end data before stage f).

The method of this invention may also include the step of providing a height sensor supported between the axle and the chassis, the height sensor outputting a signal indicating the position of the chassis relative to the axle.

In this case, the method may further include the steps of providing travel range end data indicating the extreme position of the chassis relative to the axle, storing this travel range end data in the electronic control unit, receiving a signal from a height sensor indicating the position of the chassis relative to the axis, and comparing the signal with end of range data before stage f).

The method further includes the steps of determining whether the difference between the signal from the height sensor and the end of range data exceeds a predetermined value, as well as selective control by the electronic control unit of the control unit to interrupt the flow of compressed fluid through it, if that predetermined value has been exceeded.

[0020] The invention will be further described with reference to the accompanying drawings.

[0021] Figure 1 is a schematic of the horizon leveling system and its components, in a traditional vehicle having two axles.

[0022] Figure 2, which includes sub-figures 2A, 2B and 2C, is a flow chart of the method according to the present invention for carrying out the alignment of the vehicle chassis.

[0023] Figure 3, which includes sub-figures 3A, 3B and 3C, is a flowchart of a modified method of performing vehicle chassis alignment.

[0024] Figure 4 is a schematic illustration of how the vehicle chassis is aligned using the methods shown in the operating diagrams of Figures 2 and 3.

[0025] Figure 5 is a schematic side view of the vehicle to be leveled using the method and system of the present invention.

[0026] Figure 6 is an enlarged partial cross-sectional view taken along the line 6-6 in Figure 5.

[0027] Figure 7 is a schematic view taken in the direction indicated by line 7-7 in Figure 5.

[0028] Figure 8 is a schematic horizontal view of the suspension system and control panel arranged inside the vehicle.

[0029] Similar reference numbers refer to similar parts in all drawings.

[0030] It should be understood that the term chassis as used herein generally refers to a vehicle sprung mass, which typically includes one or more components supported on hydraulic-pneumatic suspension members. This may include, but is not limited to, for example, the frame, subframe, floor and / or vehicle body. In addition, the term leveling, leveling and the like used in this document, such as, for example, the term "leveling relative to the horizon", is not intended to be limited in any way to horizontal or vertical alignment. Instead, such terms relate to substantial alignment with some pre-defined data, regardless of the orientation of such pre-defined data.

[0031] Figure 1 is a schematic illustration of a leveling system relative to a certain horizon, according to the present invention, which system has been generally indicated by reference number 1 and has been illustrated as being used in vehicle 2, such as an RV. Nevertheless, system 1 can be used in other types of vehicles, such as for example caravans, heavy truck trailers / semitrailers, ambulances, as well as passenger transport vehicles. This system can also be used in stationary equipment, such as a tow truck, which is supported on hydraulic-pneumatic suspension members, such as, for example, air springs. Vehicle 2 contains a number of wheels 3, one of which is illustrated at each corner of the vehicle, as well as the FSS hydraulic-pneumatic suspension system. This hydraulic-pneumatic suspension system includes air springs 6, 7, 8 and 9 mounted adjacent to each wheel 3 at the ends of the supporting front axle 11 and rear axle 12 and supporting the vehicle chassis 4 located thereon. For smaller vehicles, only a single axle having a pair of air springs can be used. However, for most RVs or larger attachments or vehicles, at least one axle pair having one or more air springs adjacent each end will be used.

[0032] Pneumatic springs usually have a construction comprising a pair of spaced apart end members 15 and 16 (Figures 5 and 6) with an intermediate flexible sleeve 17 forming an internal fluid chamber. Some examples of known pneumatic springs are illustrated in US Patent Nos. 5,374,037, US 4,852,861 and US 4,718,650. Pneumatic suspension members can also be used within the scope of the present invention, as disclosed in US Patent 4,712,776.

[0033] The equalizing system 1 comprises a compressor 20 which can be electrically powered or driven by a vehicle engine or in another suitable way for this purpose to supply compressed fluid, usually air, via the supply line 21 to the reservoir

- 9 or reservoir tank 22. It will be understood that such compressors are known and operate independently of the vehicle's engine. Alternatively, a dryer 23 can be used and preferably connected fluidly along line 21 to drain moisture from the compressed fluid before entering the reservoir 22. If desired, the compressed fluid can be fed directly to the air springs from the compressor without first passing through reservoir 22.

[0034] The main control valve assembly 25 includes an inlet valve 26, an outlet valve 27 and individual valves 28, 29, 30 and 31 for controlling pneumatic springs. The inlet valve 26 is in fluid communication with the reservoir 22 through the fluid supply line 33, while the outlet valve 27 is in fluid communication with the exhaust silencer 34. Individual control valves 28, 29, 30 and 31 are connected in fluid communication with individual pneumatic springs 6, 7, 8 and 9, respectively, via fluid lines 35, 36, 37 and 38. It should be particularly understood that the valve assembly 25 described above and illustrated in Figure 1 is only an example of a suitable valve assembly, any other suitable arrangement may be used herein without departing from the scope of the basic features of the present invention. For example, multi-position valves, such as 2-way or 3-way valves, can be placed in place of one or more control valves shown and described herein.

[0035] Each of the air springs may optionally have a height sensor or detector, generally indicated by reference number 40, connected thereto with any of the various known constructions. The height sensors can operate using the hallotron principle of operation, on an acoustic principle, on an infrared principle, resistance or the like, and they operate on, in or only in cooperation with pneumatic springs, and they are all well known in the field of pneumatic springs. Some examples of such height sensors for pneumatic springs, which are part of the pneumatic spring itself, are disclosed in US Patent Nos. 6,707,045, US 5,229,829 and US 4,798,369. However, as illustrated in Figure 6, the height sensor 40 may be a separate component supported on the vehicle and extending between spaced apart vehicle parts, such as for example between the axle and the chassis or vehicle body. Each height sensor 40 is preferably supported adjacent to the individual air springs, and is also in communication with the electronic control unit (ECU) 42, such as for example via the control line 43. In addition, a height limit travel signal may be sent by the height sensors indicating that one of the extreme positions, such as, for example, fully extended or fully compressed, of the associated pneumatic spring has been reached or is near. Alternatively, displacement range end data can be determined by the ECU based on a comparison of the signal from the height sensor with known displacement range end values ​​stored in the ECU. ECU 42 is shown in Figure 1 as being connected to the optional switch point 45 via a control line 46 to selectively actuate a hydraulic jack that is optional used on many RVs. Optionally, the switch may also have the ON and / or OFF positions (Figure 8) for the automatic alignment system used during vehicle operation. The ECU 42 is also connected to the height switch 49 via the control line 50, the ignition switch 51 operated by the key via the control line 52, and to the pair of indicator lamps 55 and 56 via the control lines 57 and 58 respectively. The altitude switch 49 may optionally be a multi-position altitude selection switch suitable for use when the vehicle can operate selectively at several heights. The ECU 42 is also operatively connected to the vehicle speed indicator or speedometer 59 of the vehicle via control line 60, as well as to the individual air spring control valves in the valve control unit via a number of control lines, indicated jointly by reference number 61. ECU 42 for its part is adapted to selectively actuate one or more of a number of valves. It will be understood that any suitable speed or displacement indicating assembly may be operatively connected to the ECU in addition to or alternatively to the speedometer 59.

[0036] Many of the above described components and methods of application are standard solutions in many hydraulic-pneumatic vehicle suspension systems used in RVs as well as trailers to provide a multi-position leveling system and appropriate driving characteristics for the vehicle. In addition, it will be understood that messages to and from various vehicle assemblies and components, such as, for example, ECU 42, altitude switch 49 and speedometer 59, may be sent in any suitable manner. For example, each of the assemblies and components may be wired and thus connected to another as provided for each of the various systems operating in the vehicle, the signals reported between the assemblies and components being transmitted by means of individual cables. As an example, if five different vehicle systems depend on the speedometer signal, five different wires can be connected to the speedometer to pass the signal sent by the speedometer directly from each system. Nevertheless, many vehicles now use a communication system based on a serial CAN communication bus that connects various assemblies and components with each other. Such communication systems based on the use of this serial CAN communication bus are well known and widely used. These systems may include an independent controller or alternatively may be integrated in another vehicle controller, such as for example ECU 42. One example of a suitable standard or protocol for such systems is SAE J1939. It will be understood, however, that there are many different protocols that can alternatively be used, such as CANOpen and DeviceNET, for example. One of the advantages of using a communication system based on the serial CAN communication bus is that in practice the physical wiring of the vehicle is greatly simplified. Another advantage is that the addition of a new assembly and / or system can be made without significant physical modification of the vehicle. For example, you can add a new system to your vehicle simply by properly mounting the new assembly on the vehicle, placing that assembly in communication with the communication system based on the CAN serial communication bus, as well as making any necessary modifications to the software and / or operating software according to the existing assemblies and / or components. Once installed, the new system can send and receive any other signals, information and / or data via a communication system based on the CAN serial communication bus to support the newly added system.

[0037] According to this invention, an alignment sensor or level detection unit, which has been generally indicated by reference numeral 65 and illustrated schematically in Figures 5-7, has been mounted on the chassis 4 of the vehicle or is operatively connected to it. Assembly 65 provides an alignment signal to ECU 42 via control line 66. The alignment signal indicates the orientation of the vehicle chassis. The alignment detection assembly 65 can be any type of device suitable for this purpose, such as an accelerometer, tilt sensor, gyro sensor, as well as a transducer or other assembly that can detect the position, orientation or range of the structural body swing and output a signal such as relative voltage or current, related to the approximate position, orientation, or swing range of the connected structural body. One particular type of alignment detection assembly is the biaxial accelerometer manufactured by Memsic, Inc. from North Andover, MA in the USA, referred to as the MXR299ML model. This sensor operates on a thermal principle, it generates a signal, such as, for example, the output voltage, for both the X axis and the Y axis, changing according to the angular orientation of the sensor. Accelerometer 65 provides some analog or digital value or signal that depends on the swing or loss of alignment of the vehicle chassis on which the sensor is supported. This signal is fed to ECU 42 via line 66. Accelerometer 65 can be attached to any part of the vehicle chassis, without prejudice to this invention. For example, the accelerometer can be attached to part of the frame, such as to the spreader beam, or to part of the body, such as to the roof, side wall or floor. In addition, the accelerometer can optionally be centrally mounted on the vehicle chassis. However, central mounting is not necessary.

[0038] Therefore, according to one of the features of this invention, a typical air suspension system for a vehicle as described above is used, without significant modifications made to it, except for the use of an alignment sensor or an alignment detection unit 65 which is operatively connected to the ECU 42, in combination with the corresponding software used by ECU 42, to obtain the features shown in Figures 2-4, as discussed below.

[0039] Figure 8 shows one type of control panel 70 that can be placed on the vehicle's dashboard to enable control of both the suspension system for the vehicle's driving mode during its dynamic operation as well as the horizon alignment system according to the present invention. The panel includes a height switch 49 that controls the normal mode alignment

- 12 driving of the vehicle, indicator lights 55 and 56, switch point 45, as well as horizon alignment switch 72 connected to ECU 42 via control line 73 (Figure 1). Indicator lamp 74 is connected to ECU 42 via control line 69. The switch point 45 will be moved to one of three positions, as illustrated in Figure 8. The position of the switch can be illuminated from below by using a backlight to indicate the selected position. If desired, panel 70 may be a touch screen, which would eliminate the flip-flop or rocker switches discussed above.

[0040] According to one feature of the invention, the artificial alignment or horizon has been indicated schematically by means of the dashed line 71 (Figures 5 and 6). This artificial horizon has been programmed to ECU 42 as a predetermined data. This predetermined data is the default reference plane that is used by the system to align the vehicle chassis regardless of the orientation of the vehicle axle, wheels or ground on which it is supported. Although the line 71 shown in Figures 5 and 6 has been indicated to be substantially horizontal, it will be understood that this line 71 can be placed in any desired orientation as previously determined herein.

[0041] Steps for carrying out one embodiment of the present invention are illustrated in Figure 2, the second embodiment being illustrated in Figure 3, by means of the operating diagrams shown therein. Referring to Figure 2, the vehicle operator, after the vehicle stops in an area such as a parking space, camping pitch or the like, activates the alignment system relative to a certain horizon by actuating the control switch 72 located on the panel 70 in the cabin part of the vehicle as indicated by block 75 (Figure 2A). In one preferred embodiment, this is done by pressing and holding the control switch 72 for a predetermined period of time. A similar holding of the button can also be used to uncouple the system. In this way, the possibility of unintentional start (or alternatively - disconnection) of the system, such as by hitting a switch, for example, is minimized. One example of a suitable time for holding the switch in the depressed position is a time of about 3 to about 10 seconds, and preferably about 4 seconds^ds.

[0042] The ECU 42 pre-determines whether the vehicle chassis has been aligned with the predetermined data within block 77 by comparing the signals received from the accelerometer 65 with respect to the artificial horizon 71 pre-stored in the ECU 42. If the vehicle floor or other reference plane is within a certain acceptable range on each side of this artificial horizon 71, the ECU will emit a signal and activate the indicator light 74 as shown in block 78, which will provide a visual indication to the driver that the vehicle is correctly aligned. If the ECU detects that the vehicle chassis is not aligned with the predetermined data, it will then determine whether the amount of deviation of the vehicle chassis from the alignment with the previously determined data is in the

- 13 limits of the possibility of correction made by the system, in block 79. If this amount exceeds the system's capacity, the unit will send a signal to the operator, such as an audible sound or flashing of the lamp 74, as illustrated by block 80, which will immediately make the driver aware, that the vehicle is in an excessive state of misalignment and the suspension system will not be able to compensate for the unevenness of the terrain where the vehicle is currently parked. The driver can then move the vehicle to the same location or move to a different, more level place. If the misalignment signal generated by the accelerometer 65 is within the system's ability to correct, the ECU will go to step 81, where it will detect which side of the vehicle is above the artificial horizon 71, i.e. is it the right side 62 or left side 63 as illustrated in Figure 7.

[0043] After determining in block 81 which side of the vehicle is higher, in block 82 it is ascertained (assuming for the purposes of the present description that the right side is defined as the upper side) whether the extent of misalignment is within the limitations making adjustments by the suspension system. If it is determined that the right side can be lowered sufficiently within block 82, a signal is sent via block 83 to block 84 (Figure 2C) to determine if the front part 62A or rear part 62B of the right side 62 is in a non-aligned state . After making a statement in block 84 that the front or rear part is left out of alignment, in block 85 it is determined whether it can be lowered sufficiently to correct the detected unevenness, and if allowed in block 86 a signal is sent to lower the corresponding pneumatic spring by extracting air from it, just like from a pneumatic spring 6, because it is a pneumatic spring located on the right rear side of the vehicle chassis.

[0044] If the right side 62 cannot be lowered sufficiently, block 88 (Figure 2B) determines whether the opposite side 63 can be raised sufficiently to compensate for unevenness. If this is not the case, within block 89, the indicator light 74 flashes to notify the driver that the system is still checking whether correct alignment can be obtained. If the left side 63 can be raised sufficiently, then in block 90 through block 84 it is then determined, as discussed above, whether the front or rear of the left side is in a misaligned state and whether it can be lowered, to achieve the desired alignment position.

[0045] Also in this case, if the predetermined front part or rear part cannot be lowered, it is determined in block 88 whether the opposite front part or rear part can be raised. If not, at block 91 the lamp 74 flashes to indicate that the desired alignment has not yet been achieved. After achieving alignment and determining this in block 77, as well as sending the appropriate signal to lamp 74 via block 78 (Figure 2A), the time circuit represented by block 92 re-checks the alignment of the vehicle chassis after a predetermined time such as one

- 14 hours, two hours, etc., through the previously described sequence of operations, and the necessary correction will also be made, preferably by extracting air from the pneumatic springs on the higher side, in order to maintain the alignment of the system.

[0046] It should be understood that when the left side 63 of the vehicle is defined by block 81 as the upper side, the same procedure is performed as discussed above for the right side.

[0047] Also, when the front end is determined to be out of alignment within block 84, the same procedure is performed for the front end of the eggs as discussed above for the rear end. It is preferred that the spring or air springs on the higher side or at the higher end are lowered before the spring or air springs on the lower side or at the lower end are lifted themselves, as this only involves the discharge of air from individual pneumatic springs, which will not result in stock depletion compressed air in the reservoir 22. However, if necessary, the corresponding air spring can be lifted by supplying additional compressed fluid from reservoir 22. This feature avoids premature consumption of the compressed fluid supply from reservoir 22.

[0048] Therefore, the ECU preliminarily determines, depending on the reading received from the indicator assembly 65, whether the unevenness range is too large to be compensated by the system, and also initially notifies the operator to change the vehicle. This avoids the need to attempt to align the vehicle body by activating the appropriate air springs only to then conclude that the vehicle body cannot be leveled due to the excessive unevenness of the terrain. In this way, time and unnecessary work of pneumatic spring components, fluid reserves, etc. are saved. The system also determines which side of the vehicle is the higher side, and whether it is possible to compensate for it, and whether such unevenness can be compensated and which corner or end of the higher side can be lowered to bring the vehicle body into alignment with respect to artificial horizon or previously specified data stored in ECU 42.

Also in this case, the air is preferably extracted from the air springs on the higher side or instead only from the corner air spring instead of introducing air into the lower air springs to achieve the desired level and to save stored compressed fluid. It is also beneficial to lower the vehicle chassis, sides or corners, to achieve the desired alignment, as opposed to raising its one side or corner, to achieve the desired alignment, because the lower location of the vehicle chassis, when it is stationary, facilitates the entry and exit of passengers and from the vehicle body. In this way, if the chassis of the vehicle was initially raised, the goals of alignment, entry and exit become slightly more difficult. Also in this case, it is not the height of the vehicle chassis above the wheels or axles that is adjustable; this adjustment of the vehicle body alignment relative to a predetermined artificial horizon is used by the improved system of the present invention.

[0050] ECU 42 preferably includes a standard integrated circuit that can be programmed by a person skilled in the art to obtain the features discussed above and illustrated in Figures 2-4.

[0051] A modified embodiment of the improved method is illustrated in Figures 3A-3C. After making the determination in block 79 that the extent of misalignment is within the system's capabilities, then it is determined, in block 100, which of the directions is in a state of misalignment, namely, as illustrated in Figure 3B, whether this is the right front part, left front part, left rear part, right rear part or all front side, all back side, all left side or all right side of the vehicle chassis. After this finding has been made by one of the blocks, as illustrated in Figure 3B, the system continues to the blocks of Figure 3C, where it is determined within block 101 whether the location in the non-aligned condition can be sufficiently lowered, and if so whether it will be the lower side as stated in block 102 or the lower corner as stated in block 103. In this case, too, if the position in a state of misalignment cannot be effectively lowered, the system determines, as illustrated by the alternative blocks in Figure 3C, whether the opposite orientation, be it side, end or corner, can be raised to compensate misalignment. Again, the lamp 74 will flash as illustrated by blocks 105 if the alignment of the non-aligned area cannot be made, in a similar manner as discussed above for the embodiment of Figure 2. After it has been determined that the desired alignment cannot be achieved as a result of lowering a specific place on the vehicle chassis, the appropriate air spring is actuated via the appropriate control valve 28-31 to extract air from one or more air springs, or if it is it is necessary to supply air to the appropriate pneumatic spring via a control valve connected to it, to raise an uneven corner, side or end of the vehicle chassis.

[0052] The difference between the method according to Figures 2 and 3 is that the method represented by the operating diagrams in Figure 2 can pre-determine which side is in a non-aligned state, after which it is determined whether the front or rear of such the page requires adjustment, while in the method illustrated by the flow chart of Figure 3, immediate determination is made of which vehicle location is in a non-leveled condition for subsequent adjustment.

[0053] Figure 4 is another schematic illustration of how this system works to achieve alignment with an analog or digital signal provided by accelerometer 65. Center point 110 represents accurate alignment

- 16 relative to both X and Y axes determined by accelerometer 65. In this situation, the accelerometer will send signals corresponding to the mid-range value or values ​​near the calibrated midpoint 110 of the accelerometer for readings for both the X axis and the Y axis, that both planes are aligned with the previously specified data. The inner circle 111 marked with a dashed line represents the position which, when reached, will indicate that the vehicle chassis or, alternatively, the floor or other part of the monitored vehicle chassis has been substantially aligned with the predetermined data. The outer concentric circle 112 represents the state of maximum misalignment that can be compensated by the vehicle and its suspension system.

[0054] In the particular example of Figure 4, if the signal sent exceeds the value represented by circle 112, it will be indicated that the misalignment or swing is too large and cannot be compensated by the vehicle suspension system as shown in block 79 in Figure 2A or other blocks 89, in Figures 2B and 2C. As an example, assuming that the two signals provided by accelerometer 65 intersect at point 113, this indicates that the front and left side must be lowered until this point reaches inner circle 111. If the measured point is within inner circle 111 , no further alignment by system will be required. It will be understood that this determination of too much misalignment may be used in addition or as an alternative to the end of range analysis of the displacement described above. Nevertheless, in the event that this point value falls outside the outer circle 112, as indicated by point 115, the system then indicates that the degree of misalignment is too high and that the suspension system can correct this misalignment.

[0055] Under certain circumstances, it may be argued that the orientation of the chassis is or has been within the limits of equalization by the suspension system, but after one or more equalization operations, equalization cannot be achieved. These situations are represented with blocks 89 and 91 in Figures 2B and 2C, as well as with blocks 104 and 105 in Figure 3C. An example of such a situation may occur when the operator accidentally parked the vehicle in the vicinity of a foreign object that prevents lowering the chassis part. In this situation, the suspension system could completely align the vehicle, but this foreign object will only allow partial lowering of the chassis. For example, in Figure 4, the initial orientation of the chassis was indicated by point 113, while the state of partial alignment was indicated by point 113 '. In such circumstances, an indication, such as a flashing lamp or audible signal, such as, for example, from the control panel 70, may be sent to the vehicle operator to indicate that the vehicle has been partially aligned, but still remains in a state other than the state of complete equalization. In this way, the operator is given the option of moving the vehicle to make a full alignment or accepting the existing state of partial alignment.

[0056] It should be particularly understood that the artificial horizon or the predetermined date mentioned in this document is not in any way limited to a horizontal or substantially horizontal plane. Instead, this predetermined data may be a plane aligned in any desired orientation relative to the X axis, the Y axis, or a combination thereof, without departing from the scope of the features of the present invention. One way of calibrating this predetermined data involves physically positioning the vehicle chassis in the desired orientation, such as, for example, when the chassis floor is substantially horizontal or inclined from back to front, with the front portion being substantially lower than the rear. When the vehicle chassis is physically oriented, a signal indicating the orientation is received from the alignment sensor and the data assigned to that signal is saved in the ECU as the alignment data. Then, the system operates as discussed above and repeatedly compares the signal sent from the alignment sensor with the alignment data in the ECU.

[0057] Therefore, this improved system and method according to the present invention allow alignment of the vehicle chassis, and in particular the floor or other wall of the RV vehicle, trailer or other structure, easily and efficiently, by using the existing chassis suspension system of the vehicle , by adding accelerometer 65 or another type of alignment sensor in combination with ECU 42, which has been programmed in accordance with the operating diagrams illustrated in Figures 2 and

3. ECU 42 performs values ​​related to readings in the X and Y planes sent by accelerator 65, and also adjusts the height of the vehicle through the components of the height control system, in particular air suspension springs, in order to causing the vehicle chassis to align with the previously specified data, regardless of the orientation of the ground, wheels or axle of the vehicle. This system preferably uses the existing ECU, which is used in the normal suspension system of the vehicle and the alignment due to various modifications introduced to it, in order to obtain the procedure according to the operational diagram and the effects illustrated in Figures 2 and 3.

[0058] The control system according to the present invention is also provided with appropriate locks which operate in such a way that they selectively deactivate at least part of the leveling system relative to the horizon, and also restore the system to normal vehicle height compensation after actuating switches 45 and / or 49. Directly upon activation of any of these switches, the ECU preferably automatically disengages the automatic equalization system of the present invention. Also, the speedometer 59 and / or other motion detecting component is preferably connected to the ECU 42 in such a way that, for example, through line 60, to further send the ECU 42 signal to selectively deactivate the leveling system relative to the horizon after the vehicle has been set in motion. In this way, when a speedometer or other assembly sends a signal indicating a speed greater than (0) mph, one of the alignment sensors and at least part of the ECU may be turned off. Also abandoning the "Park" position or releasing the handbrake could possibly send a signal to ECU 42 that the equalizing system should be disengaged. As discussed above, this system initially attempts to adjust the height of the vehicle by discharging air from the air springs at the higher side or end to save stored compressed fluid in reservoir 22. However, if needed, air can be supplied to the appropriate air springs from reservoir 22 through the respective individual control valves 2831, to cause the vehicle body parts to be lifted to compensate for any misalignment if necessary and / or desired.

[0059] It can easily be understood that the hydraulic-pneumatic suspension systems of the vehicle, other than those illustrated in Figure 1, can be used without prejudice to the concept of this invention, due to the fact that one of the main features is setting the level of the artificial horizon and making adjustments a suitable air spring or air springs to obtain this position, which is determined by the alignment sensor or the alignment detection unit, such as, for example, accelerometer 65. Also other types of alignment detection assemblies can be used, without prejudice to the concept of this invention. Similarly, the subject system can be used on fixed equipment other than vehicles, and pneumatic springs can be replaced by hydraulic compression members etc. without prejudice to this invention.

[0060] Although this invention has been described with reference to the above-mentioned embodiments, and particular emphasis has been placed herein on structures and mutual structural relationships between the components of the disclosed embodiments, it will be understood that other embodiments of this invention may be developed and may be developed. make many changes to the embodiments illustrated and described herein, without departing from the basic features of the invention. Obviously, modifications and changes will come to mind after reading and understanding the detailed description given previously. In connection with the above, it should be understood in particular that the above descriptive text should be interpreted as illustrative only of the present invention and not as a limitation. Therefore, it is intended that the invention be understood to include all such modifications and changes that fall within the scope of the appended claims.

Prepared and verified

Jolanta Górczak

Patent Attorney