Chassis assembly for a multi-track and multi-axle motor vehicle, motor vehicle and computer program product

Abstract

A chassis arrangement for a multi-track and multi-axle motor vehicle, having a chassis (10) which comprises the following: at least one steering axis of rotation (LDA) about which at least one wheel (1, R1-R4) of the motor vehicle can be pivoted in order to set a toe angle; at least one caster adjustment axis (NEA) about which the steering rotational axis (LDA) can be pivoted in order to adjust the caster in relation to the wheel (1, R1-R4); at least one camber adjustment axis (SEA) about which the wheel (1, R1-R4) can be pivoted in order to adjust the camber, wherein the chassis (10) is designed such that the toe angle, the caster and / or the camber can be adjusted independently of one another. The invention also relates to a vehicle having such a chassis assembly to a computer program product.

Description

[0001] Chassis arrangement for a multi-track and multi-axle motor vehicle, motor vehicle and computer program product

[0002] Description

[0003] The invention relates to a chassis arrangement for a multi-track and multi-axle motor vehicle according to claim 1, a motor vehicle with such a chassis arrangement according to claim 18, and a computer program product according to claim 21.

[0004] Conventional chassis designs of multi-track vehicles (MMTVs) can cause the vehicle to lean outwards when cornering, particularly due to positive caster on the front axle. Furthermore, the individual wheels roll in different directions during cornering. This behavior, combined with the vehicle's tendency to lean outwards, especially when considering the varying loads, deformations, contact patches, and contact pressures of the tires, as well as the potential for different wheel orientations around the vehicle's vertical axis, can lead to driving dynamics problems that impair vehicle control. Additionally, passive, competing systems (such as stabilizers) come into play and must be taken into account when calculating a vehicle's path (particularly in conjunction with an autonomous driving mode).Even well-known active systems do not eliminate the causes of vehicle dynamics problems, but at best only mitigate their effects. Furthermore, environmental conditions such as road surface condition, temperature, and foreign matter like leaves, dirt, snow, and rain can have a primary influence on the driving destination. For these reasons, conventional chassis systems are not ideal for automated vehicle control. A control loop of an autonomous vehicle control system is typically characterized by: data acquisition (sensors) - data processing (hardware and software) - actuators - chassis - monitoring of the results by the sensors. Due to the aforementioned characteristics of a conventional chassis, this control loop must be repeated multiple times for adjustments. This necessity increases exponentially with speed and is severely limited by physical constraints in several respects.In particular, cornering speed is severely limited because the conventional vehicle leans outwards when cornering (roll). The braking distance is limited by the vehicle's downward tilt in the direction of travel (pitch). Finally, the turning radius is limited by the fact that it increases with increasing speed at a constant steering angle (yaw).

[0005] The problem underlying the invention is to simplify the automated control of a motor vehicle and to improve driving dynamics.

[0006] This problem is solved by providing a chassis arrangement for a multi-track and multi-axle motor vehicle, wherein the chassis arrangement comprises a chassis comprising: at least one steering pivot axis about which at least one wheel of the motor vehicle is pivotable for adjusting a toe angle; at least one caster adjustment axis about which the steering pivot axis is pivotable for adjusting the caster with respect to the wheel; at least one camber adjustment axis about which the wheel is pivotable for adjusting the camber, wherein the chassis is designed such that the toe angle, the caster (i.e., the orientation of the steering pivot axis with respect to a plane spanned by the vehicle's transverse and vertical directions), and / or the camber (i.e., the angle of the wheel's roll) can be adjusted.the orientation of the wheel in relation to a plane spanned by the vehicle's longitudinal and vertical directions and passing through the wheel's center) can be adjusted independently of each other (especially dynamically during driving).

[0007] The term "caster" refers to the angle of the steering axis relative to a perpendicular line in the longitudinal direction of the vehicle. Specifically, caster is the distance between the wheel contact point (i.e., a point on the wheel's centerline that rests on the road surface) and the contact point of the imaginary extension of the steering axis (i.e., the point where the steering axis intersects the road surface in the direction of the vehicle's longitudinal axis, forward travel direction). With negative caster, the contact point of the steering axis is located behind the wheel contact point (when viewed in the forward travel direction), while with positive caster, it is located in front of the wheel contact point. The "steering axis" is, in particular, the axis around which the wheel rotates when a steering movement is initiated by the driver.A change in caster (the caster angle) can therefore be made without a corresponding change in camber (the camber angle) and / or toe angle. Conversely, the camber of the wheel can be changed without this causing an undesirable change in caster and / or, in particular, toe angle. However, it is possible that while caster and camber are adjustable independently, the camber depends on the toe angle. Caster and camber can, however, be adjustable without affecting the toe angle. Therefore, when caster or camber is changed, the toe angle is not changed, or at most only minimally. The steering axis, for example, can pivot around the caster adjustment axis in such a way that a negative caster relative to the wheel can be set.In particular, the caster angle with respect to at least one front wheel of the vehicle is always negative, although the amount of the negative caster angle is adjustable.

[0008] The caster adjustment axis runs transversely to the vehicle's longitudinal direction when driving straight ahead, and / or the camber adjustment axis runs parallel to the vehicle's longitudinal direction. The caster adjustment axis can coincide with the wheel axis. However, this is not mandatory. Rather, the caster adjustment axis can be offset (offset) – in principle in any direction – and / or angled to the wheel axis (especially during steering maneuvers).

[0009] According to a further development of the invention, the chassis assembly comprises an adjustment device for setting the caster and camber. With the aid of the adjustment device, the steering axis can be pivoted about the caster adjustment axis and / or the wheel can be pivoted about the camber adjustment axis. For example, the adjustment device includes a computer device that determines the caster and / or camber to be set. The computer device can be configured as a controller for individually controlling the caster, camber, and toe angle. However, this is not mandatory. Rather, the computer device could determine and specify the caster and / or camber to be set, particularly depending on speed, without requiring adjustment based on feedback signals (sensor signals). A vehicle with the chassis assembly according to the invention can, for example,The vehicle precisely follows the path specified by the computer device, which determines the caster, camber, and steering angle. Sensors for controlling the caster and / or camber, as well as the steering angle, therefore preferably serve only as a success or safety check, i.e., in particular to detect larger deviations, for example, due to a defect.

[0010] The computer system can be integrated into the vehicle's central control unit. However, it is also conceivable that the computer system is a separate unit.

[0011] The computer device is designed, for example, to determine the caster and camber as a function of the vehicle's speed in such a way as to counteract speed-dependent changes in the yaw angle and / or pitch angle. For example, the caster and camber are adjusted so that the yaw angle and / or pitch angle do not exceed a predefinable (e.g., speed-dependent) limit value.

[0012] Furthermore, the computer device can be designed to determine the caster and camber so that, when cornering, the largest possible area of ​​the tire of the wheel is in contact with the road surface.

[0013] The adjustment device includes, for example, at least one actuator for adjusting the caster angle and at least one actuator for adjusting the camber. These actuators could be, for example, linear or rotary motors. Hydraulic, pneumatic, and / or electromechanical actuators are also conceivable.

[0014] It is possible, for example, that the adjustment device for setting the wheel caster comprises a rotatable element (particularly about the caster adjustment axis), wherein the rotatable element is coupled to a steering element that defines the steering axis, so that the orientation of the steering element can be changed by rotating the rotatable element. The rotatable element can be set into rotation, in particular by means of the actuator. The steering element is, for example, (at least indirectly) coupled to the wheel (in particular a wheel hub). For example, the coupling of the steering element to the wheel is achieved via a spring damper unit (e.g., in the form of a fork tube). The spring damper unit ensures, in particular, that when the distance between the wheel and the chassis changes in the vehicle height direction (e.g.,The device counteracts and, in particular, maintains changes in the toe angle (e.g., when driving over uneven surfaces or obstacles, or when the vehicle's load changes). Furthermore, the device comprises a leg pivotally mounted to a vehicle chassis and coupled to the wheel, wherein the leg is movable in a direction perpendicular to the camber adjustment axis for adjusting the wheel's camber. The leg can be set in motion, in particular, by means of an actuator. The device may include a static element for adjusting the wheel's caster, wherein movement of the leg for camber adjustment is transmitted to the wheel via the static element of the caster adjustment. The static element is, in particular, rotationally fixed relative to the rotatable element of the caster adjustment; that is, it does not rotate with the rotatable element.

[0015] The chassis arrangement according to the invention may also include the following:

[0016] - a first chassis unit (first “active corner”) that defines the steering pivot axis, the caster adjustment axis, and the camber adjustment axis with respect to a first wheel of the vehicle, and via which the toe angle, caster, and camber are independently adjustable with respect to the first wheel; and

[0017] - a second chassis unit (second “active corner”) that defines the steering pivot axis, the caster adjustment axis and the camber adjustment axis with respect to a second wheel of the vehicle and via which the toe angle, caster and camber with respect to the second wheel can be adjusted independently of each other and independently of the caster and camber setting with respect to the first wheel.

[0018] The two wheels can therefore be adjusted independently of each other. It is also conceivable that in a vehicle with four wheels, the four wheels could be adjusted independently of each other, meaning that the toe angle, caster, and camber could be adjusted individually for each wheel, independently of the settings of the other wheels.

[0019] For example, the chassis arrangement comprises a front axle coupled to two front wheels and a rear axle coupled to two rear wheels, wherein at least one of the front wheels (in particular always) has a negative caster and at least one of the rear wheels (in particular always) has a positive caster. It is also conceivable that the chassis is designed such that, when cornering, a chassis of the vehicle tilts into the curve and the wheel (or all wheels on one side of the vehicle) tilts outwards. It is also conceivable that a driving mode (e.g., for autonomous driving) can be selected in which a negative caster is set for the front wheels (in particular always) and a positive caster is set for the rear wheels (in particular always). The invention also relates to a motor vehicle with a chassis arrangement according to the invention.For example, the adjustment device is designed to tilt the front and rear wheels on the same side of the vehicle outwards together when cornering. It is also conceivable that the adjustment device is designed to tilt the wheels of the front axle and / or the wheels of the rear axle outwards together when cornering.

[0020] There can be a negative caster angle at at least one wheel (in particular, always) on the front axle, while the caster angle at at least one wheel on the rear axle (in particular, always) can be 0 degrees, 90 degrees, or any other positive caster angle. As mentioned, the caster angle setting in a particular driving mode could be negative for the front wheels of the vehicle (caster is always negative) and positive for the rear wheels of the vehicle (caster is always positive).

[0021] The vehicle in question is, for example, a vehicle according to EP 3 359 440 B1, i.e., a vehicle with a chassis in which at least two front wheels are pivotable about the front steering axis, the front steering axes being oriented such that a negative caster is created with respect to the respective front wheel, and at least two rear wheels are pivotable about a rear steering axis, the rear steering axes being oriented such that a positive caster is created with respect to the respective rear wheel. Such a vehicle can have the characteristic of decreasing the turning radius under constant steering angle and positive acceleration, and increasing it under negative acceleration.According to the invention, the orientation and / or position of the caster adjustment axis and the camber adjustment axis can be adjusted independently of each other, which in particular allows automated steering (via computer device).

[0022] The chassis arrangement according to the invention, together with the computer device described above, enables, in particular, compensation for an increase in yaw tendency with increasing (cornering) speed, as already mentioned above. It is also conceivable that the chassis arrangement can be switched to manual control and classic chassis mechanics (e.g., "at the push of a button"), thus enabling a transition from manual to semi- or fully autonomous driving. Classic chassis mechanics include, in particular, positive caster at the front wheels. With negative caster relative to a front wheel (on the front axle), braking can unload the front axle and thus the front wheels (reversal of pitch). The aforementioned computer device can monitor and control a corresponding torque, in particular to generate uniform contact pressure at all wheels to reduce the braking distance.The chassis's inclination into the curve (as described) can result in the vehicle placing a greater load on the inner wheels than on the outer wheels. The aforementioned computer device can monitor and control this load (e.g., corresponding torques acting on the wheels) to generate a uniform contact pressure on all wheels.

[0023] The computer device (or the software running on it), i.e., the computer-aided speed-dependent adjustment of the caster and / or camber (possibly also dependent on a current toe angle), simplifies the driving of a vehicle as described in EP 3 359 440 B1. This includes, among other things, the aforementioned possibility of converting the chassis to classic chassis geometry via the caster adjustment.

[0024] The invention further relates to a computer program product for a chassis arrangement according to the invention (in particular for operating such a vehicle arrangement), wherein the computer program product comprises commands which, when the program is executed by the computer device, cause it to determine (and, for example, control) a toe angle, caster angle, and / or camber angle to be set. The determination of the caster angle and camber angle is performed, in particular, dynamically depending on the speed and / or a current toe angle of the vehicle.

[0025] In particular, the invention also relates to:

[0026] A chassis mechanics and / or chassis, preferably suitable for autonomous driving, in particular highly precise and safe, in conjunction with a (preferably computer) control system to reduce latency and increase the precision of multi-track vehicles (multi (motor) track vehicles).

[0027] Note: The chassis mechanics, particularly those described in EP 3 359 440 B, can have the property of decreasing the turning radius during acceleration (positive) at a constant steering angle, and increasing it during negative acceleration. The control system according to the invention enables the compensation of the increase in yaw tendency as an inherent property of the chassis mechanics, preferably those described in EP 3 359 440 B, with increasing (curve) speed. A multi-track vehicle according to the invention can also be switched to manual control and classic chassis mechanics ("at the push of a button"), thus enabling the transition from semi-autonomous to fully autonomous driving. Further embodiments of the motor vehicle according to the invention are as follows:

[0028] At least two wheels move in a curve on a common circular path, preferably the outer wheels moving together and the two inner wheels moving together on the same circular path, where (one of the circular paths) can be replaced by a straight line.

[0029] The mechanics of the vehicle's kinetic energy generate torques that cause pitch, yaw, or roll. Adjusting the caster and camber axes counteracts, for example, pitch (inertia during braking) and / or roll (centrifugal force during cornering).

[0030] At least one vehicle axle can be passively steered via the chassis, in which only the (tracking levers) of the steering pivot axes of this vehicle axle are connected to each other via a common tie rod.

[0031] The deflection of the other axles (especially the rear axles) can be limited by stops (rigid, spring-loaded, or damped). The deflection of the (passive) axle can be actively or passively damped, directly or indirectly, particularly to limit the toe angle relative to the rear wheels.

[0032] The landing gear can have the characteristic that precision increases and latency decreases with increasing speed. For example, cornering safety can increase with increasing speed compared to conventional landing gear (in contrast to the mechanics of conventional landing gear with decreasing precision and increasing latency), especially when using the computer control described above.

[0033] The orientation of the steering axis (the caster angle) is adjusted directly or indirectly, particularly in the range of negative caster relative to the front axle and positive caster relative to the rear axle, and can be changed while driving to meet specific requirements. At low speeds, for example, a large steering angle and minimal body roll are needed, while at higher speeds, a smaller steering angle combined with greater body roll is required. The suspension can also be equipped with an adjustable caster function, thus enabling (temporary) settings similar to a conventional suspension setup.

[0034] At least one wheel can be braked or accelerated. Two, three, or four wheels can also be accelerated or braked individually or, in particular, diagonally. This can be done, in particular, with the aid of the aforementioned computer device (especially computer control).

[0035] Changes in the toe angle with respect to a wheel can be avoided by compression or rebound of the wheel (in particular by using a spring damper unit that provides play, especially in the vehicle height direction and / or in the direction of the steering axis).

[0036] The chassis of the chassis arrangement according to the invention can generate a more uniform contact pressure across the entire contact patch compared to conventional chassis. For example, the tire can scale / deform its contact patch depending on the load; in particular, such that the entire tire width is available in conjunction with a uniform / more uniform contact pressure on all (e.g., four) wheels equally. This contrasts with conventional chassis, where this effect only occurs approximately on the outer (two) wheels when the vehicle is subjected to extreme cornering loads near the limit. Only this fact allows the conventional chassis to maintain a limited degree of safety despite outward lean during cornering, especially at increasing speeds.

[0037] Especially when driving straight ahead, at least one wheel and / or a suspension unit ("active corner") can be tilted around the vehicle's longitudinal axis for (fine) correction, without steering. This tilting function can be generated by a pivot axis (camber adjustment axis) on / through at least one wheel, without changing the direction of travel of at least that wheel.

[0038] The chassis allows for the largest possible contact patch (up to the entire tire width) of at least one tire, preferably all tires, on the road surface, especially during braking and cornering. The computer device's software (control software) uses, for example, exponential functions to calculate the travel path and mitigate operational hazards. The respective pitch, roll, and yaw moments generated by the chassis mechanics and kinetic energy follow exponential functions. Example centrifugal force: Wkin = m / 2 xv 2These functions are superimposed by different force vectors at the front and rear axles. At the rear axle, the centrifugal force vector is added to a force vector dependent on the steering angle. At the front axle, however, these are subtracted. This technical problem cannot be solved (mechanically, hydraulically, pneumatically, or electrically) without considerable technical effort. However, this problem can be solved by a freely programmable electronic (computer) control system. This can be further enhanced by incorporating self-learning functionality.

[0039] At higher speeds, especially when driving straight ahead, the software can only control at least one wheel and / or one wheel control (active corner) for (fine) correction. To achieve the desired (driving) goal, the software may complete a control loop less often (compared to conventional control systems), not at all, or only once.

[0040] The chassis, preferably in conjunction with appropriate control, can represent a multi-redundant system, since the vehicle can remain steerable via one wheel even if the control systems of all other wheels fail.

[0041] The computer device (particularly in the form of a control unit) can take into account a speed-dependent progression of the yaw tendency due to the chassis mechanics. The electronic control unit can calculate this. At least one axis (steering axis, caster adjustment axis, or camber adjustment axis) is actively controlled.

[0042] Preferably, each individual wheel is controlled separately to increase safety and reliability. This control can be redundant (at least one actuator per wheel and / or per wheel control (active corner), in particular at least three actuators per wheel). Multi-redundancy can be achieved by ensuring that, in the event of a failure of at least one wheel control, the vehicle remains steerable and thus controllable even if at least two wheel control units fail. Multi-redundancy can also be achieved by ensuring that, in the event of a failure of at least three wheel control units, the vehicle remains steerable and thus controllable even if at least four individual wheel control units (active corners) fail. The computer device (in particular the controller) can be programmable (in particular freely) and, for example,The device must have at least the following individual functions: emergency program, remote intervention, training, self-learning, and progressive, degressive, and linear control of the actuators. The computer device can be switched to adapt to manual / human control requirements (human control loop).

[0043] At higher speeds, especially when driving straight ahead, only one wheel and / or one active corner can be moved around one of its axes (steering axis, camber axis, caster adjustment) for (fine) correction. Depending on the required size and speed of the change in direction, the actuators can be controlled sequentially, individually, axle by axle, only the inner, only the outer, diagonally, or all simultaneously, either identically or differently.

[0044] The computer system (control unit) can monitor the uniform contact pressure of all wheels during cornering and / or braking. With a conventional suspension setup, the wheels are tilted inwards (camber setting), especially when cornering. However, this leads to excessive unloading of the outer tire (particularly on the outside of the curve) because the outer sidewall is essentially folded away by the lateral forces, while the inner sidewall stands upright. This reduces the contact patch under the same load. This results in higher pressure per square centimeter, which initially leads to better grip between the tire rubber and the road surface. However, this effect is limited and, if this contact patch is overloaded, leads to a sudden loss of traction.The chassis of the chassis arrangement according to the invention develops different properties, particularly through an outward tilting of the wheels, opening up new possibilities and exhibiting a higher safety potential. Thus, by tilting the wheel outwards, the contact area initially appears to be reduced, but then, depending on the load, scales itself from the outside (outer side of the curve) inwards to 100% of the tire width.

[0045] The computer device (control unit) can assist with the aforementioned "steering out of the curve." At least one wheel, preferably at higher speeds, can be steered for cornering (in particular, only the toe angle is changed with respect to this wheel, but not the caster and camber). The invention is explained in more detail below with reference to exemplary embodiments. The figures show:

[0046] Fig. 1 shows a front view of a chassis arrangement according to a first embodiment of the invention;

[0047] Fig. 2 shows the chassis arrangement from Fig. 1 in side view;

[0048] Fig. 3 shows the chassis arrangement from Fig. 1 in perspective view;

[0049] Fig. 4 shows the chassis arrangement from Fig. 1 in perspective view with a changed camber angle;

[0050] Fig. 5 shows the chassis arrangement from Fig. 4 in front view;

[0051] Fig. 6 shows a perspective view of a chassis arrangement according to a second embodiment of the invention;

[0052] Fig. 7 shows the chassis arrangement from Fig. 6 in front view;

[0053] Fig. 8 shows the perspective view of the chassis arrangement from Fig. 6 with a changed caster angle; and

[0054] Fig. 9 shows the chassis arrangement from Fig. 8 in front view.

[0055] The chassis arrangement 100 according to the invention of a (motor vehicle not shown) depicted in Figures 1 to 3 comprises a chassis 10 with an active chassis unit FE (“active corner”) for changing the position of a wheel 1 and its steering axis LDA of the motor vehicle relative to a vehicle chassis. The chassis 10 forms the steering axis LDA of the chassis unit FE, about which the wheel 1 can pivot to adjust a toe angle (steering angle) of the wheel 1, i.e., the angle that the wheel 1 makes with the longitudinal axis of the vehicle. The steering axis LDA is realized by a corresponding steering element 11 (e.g., a steering rod), which, in particular here, is coupled to a hub of the wheel 1 via a spring damper unit in the form of a slider tube 12 (strut). The track angle is adjusted using an actuator 1 11 coupled to the steering element 11 (e.g. in the form of an electric motor).Furthermore, the chassis 10 forms, in particular, a caster adjustment axis NEA of the chassis unit FE, running parallel to the wheel axis RA, about which the steering pivot axis LDA (the steering element 11) can pivot for adjusting the caster relative to wheel 1. Additionally, the chassis 10 provides a camber adjustment axis SEA, running parallel to the vehicle's longitudinal axis, about which wheel 1 can pivot for adjusting its camber. The caster adjustment axis NEA does not necessarily have to coincide with the wheel axis RA. It is also conceivable that the caster adjustment axis NEA runs off-axis (offset) – in principle in any direction – relative to the wheel axis RA. For example, the caster adjustment axis NEA runs offset from the wheel axis RA in the vehicle's longitudinal and / or vertical direction. It is possible that an offset caster adjustment axis NEA relative to the wheel axis could be used to change the vehicle's ride height.It is conceivable that only one wheel is changed in position relative to the vehicle in this way.

[0056] The caster and camber are adjusted using an adjusting device 20, which accordingly has a caster adjustment 200 and a camber adjustment 300. The caster adjustment allows the steering axis LDA to pivot about the caster adjustment axis, while the camber adjustment allows the wheel 1 to pivot about the camber adjustment axis SEA. The chassis 10 – and in particular the adjusting device 20 – is designed such that the toe angle, caster, and camber can be adjusted independently of each other.

[0057] The caster adjustment 200 of the adjusting device 20 comprises a rotatable element in the form of a (e.g., ring-shaped) rotor 21, which is coupled to the steering element 11. An actuator 211 is also provided for moving the rotor 21, whereby the actuator 211 sets the rotor 21 into rotation about the caster adjustment axis NEA, which runs through the center point of the rotor 21. Rotation of the rotor 21, in turn, causes the steering element 11 (i.e., the steering axis LDA) and the components coupled to the steering element 11 (in particular the actuator 11 and the spring damper unit, especially the slider tube 12) to pivot about the caster adjustment axis NEA.

[0058] The camber adjustment 300 of the adjusting device 20 comprises an actuator 311, which drives a leg 302 that can be articulated to a vehicle chassis via a joint 301. The leg 302 is connected to a wheel leg 304 via a further joint 303. The wheel leg 304, in turn, is coupled to a static element in the form of a stator 22 of the caster adjustment 200. A movement (in particular linear) of the leg 302 effected by the actuator 311 (in particular in the direction of the wheel 1 or conversely in the (transverse) direction to the vehicle chassis) generates a torque acting via the stator 22 on the unit with the actuator 11, the steering element 11, and the slider tube 12, which results in a pivoting movement of the wheel 1 about the camber adjustment axis SEA. The camber adjustment axis SEA is defined by pivot points of a joint connection, via which the vehicle chassis is coupled to the stator 22.The joint connection in turn comprises joint elements 23, 24 connected to the stator 22.

[0059] When the wheel camber is changed by activating the actuator 311 and the corresponding pivoting movement of the wheel 1 outwards or inwards, the orientation of the steering element 11 with respect to the toe angle (in particular the rotation of the steering axis LDA) remains at least substantially unchanged. This also applies in particular to the toe angle, whereby a compensating movement of the wheel relative to the steering element 1 along the steering axis can be effected with the aid of the slider tube 12. This further contributes to maintaining the toe angle, especially when the wheel camber is changed.

[0060] The adjusting device 20 also includes a computer device (not shown) with which the actuators 111, 211, 311, and thus the toe angle, caster, and camber are adjusted. In particular, the computer device provides corresponding adjustment signals. The adjustment of the toe angle, caster, and camber (in particular, the control of the toe angle, caster, and camber) is performed, for example, dynamically depending on the vehicle's speed. For instance, the adjustment of the toe angle, caster, and camber is carried out in such a way as to counteract a speed-dependent change in a yaw angle and / or a pitch angle, as already explained above.

[0061] Figures 4 and 5 show the chassis unit FE of Figures 1 to 3 with a modified camber (10° compared to 0° in Figures 1 to 3). The caster angle is zero, as in Figures 1 to 3. Figures 4 and 5 also indicate a section CH of the vehicle chassis to which the leg 302 is articulated via the linkage 301.

[0062] Figures 6 and 7 show a chassis 10 according to a further embodiment of the chassis arrangement according to the invention. The chassis 10 comprises four chassis units FE 1 - FE 4, each designed analogously to the chassis unit FE of Figures 1 to 3. Each of the chassis units FE 1 - FE 4 is assigned to a wheel R1 - R4 of the vehicle. The chassis units FE 1 - FE 4 can be operated (in particular, controlled) independently of one another, especially by means of the computer device described above and in connection with Figures 1 to 3. Thus, the track angle, caster, and camber can be individually adjusted for each wheel R1 - R4 (in particular dynamically, e.g., speed-dependent). The setting of the track angle, caster, and camber can therefore be changed without affecting the track angle, caster, and / or camber with respect to the other wheels.

[0063] Figures 8 and 9 show the chassis 10 from Figures 6 and 7, with a negative caster angle (-45°) set for the front wheels (wheels R1, R2) and a positive caster angle (+45°) set for the rear wheels (wheels R3, R4). As mentioned, the caster and camber settings for wheels R1-R4 are independent of each other. It is therefore conceivable, for example, that one of the front wheels has a different caster angle than the other. The amount of caster for the front wheels can also differ from the amount of caster for the rear wheels.

Claims

Patent claims 1. Chassis arrangement for a multi-track and multi-axle motor vehicle, comprising a chassis (10) comprising the following: - at least one steering pivot axis (LDA) about which at least one wheel (1 , R1 -R4) of the motor vehicle can be pivoted to adjust a toe angle; - at least one caster adjustment axis (NEA) about which the steering pivot axis (LDA) can be pivoted for adjusting the caster in relation to the wheel (1 , R1 -R4); - at least one camber adjustment axis (SEA) about which the wheel (1 , R1 -R4) can be pivoted for adjusting the camber, wherein - the chassis (10) is designed such that the track angle, caster and / or camber can be adjusted independently of each other.

2. Chassis arrangement according to claim 1, characterized in that the caster adjustment axis (NEA) runs transversely to the longitudinal direction of the vehicle and / or the camber adjustment axis (SEA) runs parallel to the longitudinal direction of the vehicle.

3. Chassis arrangement according to one of claims 1 or 2, characterized by an adjusting device (20) for adjusting the caster and camber.

4. Chassis arrangement according to claim 3, characterized in that the adjusting device (20) has a computer device that determines a caster and / or camber to be adjusted.

5. Chassis arrangement according to claim 4, characterized in that the computer device is configured to determine the caster and camber depending on the speed of the vehicle in such a way as to counteract a speed-dependent change in a yaw angle and / or a pitch angle.

6. Chassis arrangement according to claim 4 or 5, characterized in that the computer device is configured to determine the caster and camber in such a way that, when cornering, the largest possible area of ​​a tire of the wheel (1 , R1 -R4) is in contact with the road surface.

7. Chassis arrangement according to one of claims 3 to 6, characterized in that the adjusting device (20) has at least one actuator (21 1 ) for adjusting the caster and at least one actuator (31 1 ) for adjusting the camber.

8. Chassis arrangement according to one of claims 3 to 7, characterized in that the adjusting device (20) for adjusting the caster of the wheel (1 , R1-R4) comprises a rotatable element (21 ), wherein the rotatable element (21 ) is coupled to a steering element (11 ) defining the steering axis (LDA), so that the orientation of the steering element (1 1 ) can be changed by rotating the rotatable element (21 ).

9. Chassis arrangement according to claims 7 and 8, characterized in that the rotatable element (21 ) can be set into rotation by means of the actuator (211 ).

10. Chassis arrangement according to one of claims 3 to 9, characterized in that the adjusting device (20) comprises a leg (302) which is pivotably articulated to a vehicle chassis (CH) and coupled to the wheel (1 , R1 -R4), wherein the leg (302) is movable in a direction perpendicular to the camber adjustment axis (SEA) for adjusting the camber of the wheel (1 , R1 -R4).

11. Chassis arrangement according to one of the preceding claims insofar as it relates back to claims 7 and 10, characterized in that the leg (302) can be set in motion by means of the actuator (311).

12. Chassis arrangement according to claim 3 insofar as it relates backward to claims 8 and 10, characterized in that the adjusting device (20) for adjusting the caster of the wheel (1 , R1-R4) has a static element (22), wherein a movement of the leg (302) for adjusting the camber is transmitted to the wheel (1 , R1-R4) via the static element (22).

13. Chassis arrangement according to one of the preceding claims, characterized in that the steering pivot axis (LDA) is pivotable about the caster adjustment axis (NEA) in such a way that a negative caster can be set.

14. Chassis arrangement according to one of the preceding claims, characterized by - a first chassis unit (FE 1) that defines the steering axis (LDA), the caster adjustment axis (NEA) and the camber adjustment axis (SEA) with respect to a first wheel (R1) of the vehicle and via which the toe angle, caster and camber with respect to the first wheel (R1) are independently adjustable; and - a second chassis unit (FE 2-4) which aligns the steering axis (LDA), the caster adjustment axis (NEA) and the camber adjustment axis (SEA) with respect to a second determines the wheel (R2-R4) of the vehicle and allows the toe angle, caster and camber in relation to the second wheel (R2-R4) to be adjusted independently of each other and independently of the caster and camber setting in relation to the first wheel (R1).

15. Chassis arrangement according to one of the preceding claims, characterized by a front axle coupled with two front wheels (R1 , R2) and a rear axle coupled with two rear wheels (R3, R4), wherein at least one of the front wheels (R1 , R2) has a negative caster and at least one of the rear wheels (R3, R4) has a positive caster.

16. Chassis arrangement according to one of the preceding claims, characterized in that the chassis (10) is designed such that when cornering, a chassis (CH) of the vehicle tilts into the curve and the wheel (R, R1 -R4) tilts outwards.

17. Chassis arrangement according to one of the preceding claims, characterized in that the caster adjustment axis (NEA) is offset from the wheel axis (RA) and / or angled to the wheel axis (RA).

18. Motor vehicle with a chassis arrangement (100) according to one of the preceding claims.

19. Motor vehicle according to claim 18 insofar as it relates backwards to claim 3, characterized in that the adjusting device (20) is designed to tilt the front and rear wheels (R1 , R3, R2, R4) of the same side of the vehicle outwards together when cornering.

20. Motor vehicle according to claim 18 or 19 insofar as related back to claim 4, characterized in that the adjusting device (20) is designed to tilt the wheels (R1 , R2) on a front axle of the vehicle together and / or the wheels (R3, R4) on a rear axle of the vehicle together outwards when cornering.

21. Computer program product for a chassis arrangement according to claims 1 to 17, insofar as related back to claim 4, wherein the computer program product comprises instructions which are executed by the computer device during the execution of the program. of claim 4 cause these to determine a toe angle to be set, a caster angle to be set and / or a camber angle to be set.

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