A variable track width vehicle with a lateral stability control system

Abstract

A variable track width vehicle with a lateral stability control system, the vehicle comprising: a first wheel assembly (9L) connected to a vehicle chassis load-carrying structure (1) and comprising a first wheel (11L) positioned on a first side of a vehicle longitudinal axis (X0); a second wheel assembly (9R) connected to the vehicle chassis load-carrying structure (1) and comprising a second wheel (11R) positioned on a second side of the vehicle longitudinal axis (X0) opposite to the first side; a first lateral adjustment mechanism (7L) for adjusting a first distance (L1) of the first wheel (11L) with respect to the vehicle longitudinal axis (X0); a second lateral adjustment mechanism (7R) for adjusting a second distance (L2) of the second wheel (11R) with respect to the vehicle longitudinal axis (X0); a control unit (C) configured to control the first lateral adjustment mechanism (7L) and the second lateral adjustment mechanism (7R); wherein the first distance (L1) is adjustable to a different value than the second distance (L2).

Description

[0001] A VARIABLE TRACK WIDTH VEHICLE WITH A LATERAL STABILITY CONTROL SYSTEM

[0002] TECHNICAL FIELD

[0003] The present invention relates to a variable track width vehicle equipped with a lateral stability control system.

[0004] BACKGROUND ART

[0005] There are continuous efforts to enhance the stability of wheeled vehicles, particularly those with a narrow track width relative to the height of their center of gravity, making them inherently less resistant to lateral forces and therefore less stable compared to other vehicles.

[0006] For example, various active suspension systems enable vehicle body tilting to facilitate use in different driving environments. These systems adjust vehicle stability in response to various lateral accelerations resulting from different combinations of vehicle speeds, driving trajectory radii, road camber, and crosswind situations.

[0007] SUMMARY

[0008] The aim of the present invention is to provide improvements to a suspension system for a vehicle, enabling efficient self-balancing.

[0009] The invention pertains to a vehicle equipped with a variable track width and a lateral stability control system designed to enhance lateral stability, particularly under conditions that typically challenge vehicular stability, such as cornering, driving on inclined surfaces, or in crosswind conditions. This system is particularly beneficial for vehicles with a high center of gravity relative to their track width, which are more susceptible to lateral forces. The lateral stability control system adjusts the lateral positions of the wheels relative to the vehicle longitudinal axis to counteract destabilizing forces related to lateral accelerations.

[0010] The vehicle includes individually adjustable lateral positioning systems for each wheel, allowing the wheels to move closer to or further from the vehicle longitudinal axis as needed.

[0011] The control unit can be configured to adjust the distances of the wheels from the vehicle longitudinal axis based on detected vehicle velocity and steering wheelturn angle. This adjustment redistributes the vehicle weight across the wheels to enhance stability and counteract the effects of lateral forces.

[0012] The proposed system may use toe angle control actuators and trailing arm position control actuators that require less energy compared to full-body tilting mechanisms, resulting in a more energy-efficient system that is simpler and potentially more reliable.

[0013] The functionality of the system presented herein is achieved through a combination of mechanical adjustments and controlled actuation, supported by realtime sensor feedback and a control algorithm.

[0014] The invention relates to a variable track width vehicle with a lateral stability control system. The vehicle comprises a first wheel assembly connected to a vehicle chassis load-carrying structure and comprising a first wheel positioned on a first side of a vehicle longitudinal axis and a second wheel assembly connected to the vehicle chassis load-carrying structure and comprising a second wheel positioned on a second side of the vehicle longitudinal axis opposite to the first side. The vehicle also comprises a first lateral adjustment mechanism for adjusting a first distance of the first wheel with respect to the vehicle longitudinal axis and a second lateral adjustment mechanism for adjusting a second distance of the second wheel with respect to the vehicle longitudinal axis. A control unit is configured to control the first lateral adjustment mechanism and the second lateral adjustment mechanism, wherein the first distance is adjustable to a different value than the second distance.

[0015] The control unit can be configured to adjust the first lateral adjustment mechanism and the second lateral adjustment mechanism based on readings of the vehicle velocity detected by a velocity sensor and a turn angle of a steering wheel detected by a steering wheel sensor.

[0016] The first wheel assembly can be connected to the vehicle chassis loadcarrying structure via a first pivot mechanism pivotable about a first vertical axis and further comprises a first pivot sensor for generating a first pivot signal corresponding to a pivot angle of the first pivot mechanism about the first vertical axis, wherein the first distance is determined as a function of a pivot of the first wheel assembly about the first vertical axis; and the second wheel assembly can be connected to the vehicle chassis load-carrying structure via a second pivot mechanism pivotable about a second vertical axis and further comprises a second pivot sensor for generating a second pivot signal corresponding to a pivot angle of the second pivot mechanismabout the second vertical axis, wherein the second distance is determined as a function of a pivot of the second wheel assembly about the second vertical axis. The control unit can be configured to control the first lateral adjustment mechanism and the second lateral adjustment mechanism based on the first pivot signal and the second pivot signal.

[0017] Preferably, the first pivot mechanism may comprise a first trailing arm having its first end connected to the vehicle chassis load-carrying structure such that it is pivotable about a first horizontal axis and about the first vertical axis and having its second end connected to the first wheel by means of a first steering knuckle such that the first wheel is turnable about a third vertical axis; and the second pivot mechanism may comprise a second trailing arm having its first end connected to the vehicle chassis load-carrying structure such that it is pivotable about a second horizontal axis and about the second vertical axis and having its second end connected to the second wheel by means of a second steering knuckle such that the second wheel is turnable about a fourth vertical axis. The first lateral adjustment mechanism may comprise a first trailing arm position control mechanism for adjusting the turn angle of the first trailing arm around the first vertical axis and a first toe angle control mechanism for adjusting the turn angle of the first steering knuckle about the third vertical axis; and the second lateral adjustment mechanism may comprise a second trailing arm position control mechanism for adjusting the turn angle of the second trailing arm around the second vertical axis and a second toe angle control mechanism for adjusting the second steering knuckle about the fourth vertical axis. The angle of the first trailing arm can be adjustable to a different value than the angle of the second trailing arm. The angle of the first steering knuckle can be adjustable to a different value than the angle of the second steering knuckle. The control unit can be configured to adjust the distances by controlling the operation of the first trailing arm position control mechanism, the second trailing arm position control mechanism, the first toe angle control mechanism and the second toe angle control mechanism.

[0018] The first pivot mechanism may comprise a first resilient element, such as a spring element or a push rod of a fixed length connected to a flexible element such as a torsion bar, connected on its first end to the vehicle load-carrying structure and capable of restraining the vertical movement of the first wheel; and the second pivot mechanism may comprise a second resilient element, such as a spring element or a push rod of a fixed length connected to a flexible element such as a torsion bar,connected on its first end to the vehicle load-carrying structure and capable of restraining the vertical movement of the second wheel.

[0019] If the control algorithm of the control unit requires a given wheel to be placed at a predefined distance further from the vehicle longitudinal axis, it commands its trailing arm position control system to start rotating the trailing arm about the first or second vertical axis, respectively, so that the second end of the trailing arm is moved further away from the vehicle longitudinal axis. If the toe angle control system is present, the algorithm will command it to decrease (toe-out) the toe angle of the given wheel to a predefined value. Once the desired position is reached, the control algorithm may command the toe angle control system to set the toe angle to a certain predefined value and the trailing arm position control system to stop rotating the respective trailing arm.

[0020] If the control algorithm of the control unit requires a given wheel to be placed at a predefined distance closer to the vehicle longitudinal axis, it commands its trailing arm position control system to start rotating the trailing arm about the first or second vertical axis, respectively, so that the second end of the trailing arm is moved closer to the vehicle longitudinal axis. If the toe angle control system is present, the algorithm will command it to increase (toe-in) the toe angle of the given wheel to a predefined value. Once the desired position is reached, the control algorithm may command the toe angle control system to set the toe angle to a certain predefined value and the trailing arm position control system to stop rotating the respective trailing arm.

[0021] As a result of the operation of the apparatus, the first and second wheels can be independently positioned laterally at a given distance from the vehicle longitudinal axis. Specifically, the first wheel and the second wheel can be located in a continuum of positions between two extreme positions relative to the longitudinal axis of the vehicle: the first extreme position is when the respective wheel is at its closest distance to the longitudinal axis of the vehicle, while the second extreme position is when the respective wheel is at its furthest distance from the vehicle longitudinal axis.

[0022] A vehicle employing such a suspension system has the advantage of using differential lateral positioning of its wheels to enhance and improve its lateral stability by counteracting lateral forces resulting from lateral accelerations experienced whendriving in curves, over road surfaces with high camber, or in strong crosswind conditions.

[0023] With respect to the designs of the first and second embodiment, when a lateral force resulting from such lateral acceleration is detected by the control unit sensors, the unit can command the wheel on the external side of the trajectory curve, the less elevated side of the road camber, or the downwind side of the vehicle in crosswind conditions to be moved further from the longitudinal axis of the vehicle. It may also command the opposite wheel to be moved closer to the vehicle longitudinal axis.

[0024] As a result, in the first and second embodiment, the two wheels are located at different horizontal distances from the vehicle center of mass, creating an imbalance between the portions of weight supported by each wheel. The portion of the vehicle weight supported by the wheel located closer to the longitudinal axis of the vehicle increases, while the portion of the weight supported by the wheel located further from the vehicle longitudinal axis decreases. This creates a differential between the forces applied to the respective resilient elements, causing the resilient element related to the wheel located closer to the vehicle longitudinal axis to contract further, while the resilient element related to the wheel located further from the vehicle longitudinal axis expands.

[0025] In the first and second embodiment, as the two resilient elements contract and expand simultaneously, the respective trailing arms rotate about the first and second horizontal axes, changing the vertical position of the two wheels relative to the vehicle center of mass. The wheel located closer to the vehicle longitudinal axis is lifted higher relative to the vehicle center of mass, while the wheel located further from the vehicle longitudinal axis is lowered relative to the vehicle center of mass.

[0026] In the first and second embodiment, due to the placement of the two wheels at different heights relative to the vehicle center of mass, the vehicle body leans towards the wheel closer to the vehicle longitudinal axis. The control system ensures that the wheel on the inner side of a curved trajectory, uphill side of a road camber, or the upwind side in crosswind situations, is lifted, while the opposite wheel is lowered. This results in a tilt of the vehicle main body similar to that used in two-wheel vehicles to achieve lateral stability under similar driving conditions. An additional advantage of this system is the possibility of installing a heavier cabin, such as a completely enclosed cabin. The excessive tilting of a vehicle with such a cabin, due to therelatively high position of its center of gravity, is compensated by the lateral stability control system.

[0027] With respect to the designs of the third and fourth embodiment, when a lateral force resulting from such lateral acceleration is detected by the control unit sensors, the unit can command the wheel on the internal side of the trajectory curve, the more elevated side of the road camber, or the upwind side of the vehicle in crosswind conditions to be moved further from the longitudinal axis of the vehicle. It may also command the opposite wheel to be moved closer to the vehicle longitudinal axis.

[0028] In the third and fourth embodiment, both pivot mechanisms comprise resilient elements which connect the vehicle load carrying structure with the knuckle heads, or trailing arms. As a wheel is being displaced further away from the vehicle’s logitudinal axis, with intermediation of its respective resilient element, it exerts a pulling lateral force onto the vehicle’s load carrying structure. That lateral force may not be fully counterbalanced by any other forces at play (eg. centrifugal force, gravity or aerodynamical forces). In case of a three wheeled vehicle, or any other vehicle, whose construction allows for titling, the lateral force exerted by the wheel displaced further away from the vehicle’s longitudinal axis onto the vehicle’s load carrying structure will cause displacement of the center of gravity of the vehicle towards that wheel and resulting tilt of the vehicle in the same direction.

[0029] Furthermore, in the third and fourth embodiment, since the overall effective length of the resilient elements varies only within certain defined limits, the lateral movement of the wheel will cause the resilient element’s end connected to the trailing arm, or knuckle head to follow a nearly-circular trajectory with center in point of connection of the resilient element to the vehicle’s load carrying structure. Such nearcircular trajectory of movement will cause the lateral movement of the wheel to always be complemented by a component of vertical movement in relation to the vehicle’s load carrying structure. In case of wheel’s movement further away from the vehicle’s longitudinal axis the vertical component with be directed upwards. As a result the wheel displaced further away from the longitudinal axis will also be moved upwards in relation to the vehicle’s load carrying structure. Assuming the wheels maintaining their contact with the road surface, this upward movement will cause further strengthening of the vehicle’s tilt in direction of the displaced wheel.Finally, in the third and fourth embodiment, the vehicle’s tilting action in direction of the wheel displaced away from vehicle’s longitudinal axis displaces the vehicle’s center of gravity and as such it changes the vehicle’s overall balance. Specifically, the vehicle’s center of gravity may me displaced to such extent that it will significantly increase the load on the wheel displaced further away from the vehicle’s longitudinal axis and decrease the load on the opposite wheel. This will cause additional contraction of the resilient element on the side of the wheel displaced further away from the vehicle’s longitudinal axis and expansion of the resilient element on the opposite side. As a result, the vehicle’s tilt towards the side of the wheel displaced further from the vehicle’s longitudinal will be further deepened.

[0030] In the third and fourth embodiment, the control system ensures that the wheel on the inner side of a curved trajectory, uphill side of a road camber, or the upwind side in crosswind situations, is displaced further away from the vehicle’s longitudinal axis. This results in a tilt of the vehicle main body similar to that used in two-wheel vehicles to achieve lateral stability under similar driving conditions. An additional advantage of this system is the possibility of installing a heavier cabin, such as a completely enclosed cabin. The excessive tilting of a vehicle with such a cabin, due to the relatively high position of its center of gravity, is compensated by the lateral stability control system.

[0031] The described suspension design enables the construction of three- and four-wheeled vehicles that are relatively narrow and thus more space-efficient compared to traditional solutions, while being significantly more resistant to lateral accelerations and crosswind situations.

[0032] Several known vehicle designs aim to fulfill a similar mission, particularly various three- and four-wheeled tilting vehicles with dedicated motorized bodyleaning mechanisms. However, such motorized tilting mechanisms require significant additional energy and power to overcome the inertia forces when rapidly rotating the vehicle body mass about an axis parallel to the vehicle longitudinal axis, which increases energy consumption and decreases overall energy efficiency. Additionally, the forces involved in rapidly tilting or rotating the vehicle body mass necessitate the use of extremely robust and heavy components, further decreasing overall efficiency.

[0033] To achieve the goal of stabilizing the vehicle, the design predominantly relies on the vehicle body's own weight, the change of shape of the support envelope provided by the vehicle’s wheels and change of location of its center of mass relativeto the support envelope. This shift is enabled by changing the wheels' position relative to the vehicle longitudinal axis during forward motion.

[0034] Lateral movement of the wheels can be supported by controlled changes in the wheels' toe angle. Toe angle control actuators - if present govern the toe-in and toe-out angle of each respective wheel. Combined with the vehicle's linear motion, this allows the wheels to travel laterally and change their position relative to the vehicle longitudinal axis in a significantly more efficient way.

[0035] If the toe angle control actuators are present the energy required for the system to function effectively is minimal, primarily consumed by the toe angle control actuators themselves. In such situation the trailing arm positioning system and its actuators, are used mainly to stabilize the angular position of the trailing arms once the rear wheels reach their desired lateral location.

[0036] The design is characterized by significantly higher energy efficiency compared to existing solutions. Since the system does not need to exert significant forces to overcome the rotational inertia of the vehicle body, it represents a lighter, less complex, less costly to manufacture, and more reliable solution compared to other known mechanisms.

[0037] In a specific first embodiment of the suspension system, the first lateral adjustment mechanism may comprise a first trailing arm position control actuator for adjusting the lateral position of the first trailing arm with respect to the vehicle longitudinal axis; and the second lateral adjustment mechanism may comprise a second trailing arm position control actuator for adjusting the lateral position of the second trailing arm with respect to the vehicle longitudinal axis.

[0038] Optionally, the first toe angle control mechanism may comprise a first toe angle control actuator with its first end connected to the first steering knuckle and capable of controlling the angular position of the first steering knuckle; and the second toe angle control mechanism may comprise a second toe angle control actuator with its first end connected to the second steering knuckle and capable of controlling the angular position of the second steering knuckle.

[0039] Optionally, the first pivot mechanism may comprise a first yoke element connected to the chassis load-carrying structure such that it is pivotable about the first horizontal axis, wherein the second end of the first trailing arm is connected to the first yoke element such that the first trailing arm is pivotable about the first vertical axis; and the second pivot mechanism may comprise a second yoke elementconnected to the chassis load-carrying structure such that it is pivotable about the second horizontal axis, wherein the second end of the second trailing arm is connected to the second yoke element such that the second trailing arm is pivotable about the second vertical axis. The second end of the first trailing arm position control actuator can be connected to the first yoke element, and the second end of the second trailing arm position control actuator is connected to the second yoke element.

[0040] Optionally, the first pivot mechanism may comprise a first resilient element connected on its first end to the vehicle load-carrying structure, on its second end connected to first yoke element and capable of restraining the vertical movement of the first wheel; and the second pivot mechanism may comprise a second resilient element connected on its first end to the vehicle load-carrying structure, on its second end connected to second yoke element and capable of restraining the vertical movement of the second wheel.

[0041] The first embodiment of the suspension system utilizes a combination of toe angle control actuators and trailing arm position control actuators to adjust the lateral positions of the wheels. This dual-actuator system allows for precise and independent control of each wheel position relative to the vehicle longitudinal axis, enhancing lateral stability. The use of pivot mechanisms and trailing arms that can pivot about both vertical and horizontal axes provides a robust and flexible suspension system capable of adapting to various driving conditions. Additionally, the system's ability to adjust the toe angle of each wheel independently ensures optimal alignment and stability, reducing the risk of excessive tilting and improving overall vehicle handling. In this first embodiment, the resilient elements of the suspension are directly connected to the vehicle chassis load carrying structure. The tilt of the vehicle is obtained uniquely through difference in level of compression of the resilient elements of the suspension resulting from difference of load applied each resilient element, itself resulting from difference of lateral positioning of the two wheels.

[0042] In a specific second embodiment of the suspension system, the a rotary element can be connected to the vehicle load carrying structure by a joint, allowing its rotation around a substantially horizontal axis. The first pivot mechanism may comprise a first resilient element connected on its first end to the first end of a rotary element, on its second end connected to first trailing arm and capable of restraining the vertical movement of the first wheel; and the second pivot mechanism maycomprise a second resilient element connected on its first end to the second end of a rotary element, on its second end connected to second trailing arm and capable of restraining the vertical movement of the second wheel.

[0043] This second embodiment employs an additional rotary element connecting the first ends of resilient elements to the vehicle’s load carrying structure, while second ends of the resilient elements are directly connected to the trailing arms. The rotary element can rotate around a substantially horizontal axis parallel to the vehicle’s longitudinal axis. The first and second ends of the resilient elements are connected to the rotating element and the trailing arms respectively, such that a change of lateral positioning of one wheel can cause a rotation of the rotating element and subsequently a change of vertical positioning of the second wheel. That change of vertical positioning can further enhance the desired tilting action of the vehicle, further improving its lateral stability control.

[0044] Preferably, the control unit is configured to adjust the first lateral adjustment mechanism and the second lateral adjustment mechanism based on accelerometers measuring lateral forces acting on the vehicle. The use of accelerometers allows for precise and real-time adjustments to the lateral wheel positioning. Accelerometers are highly sensitive to changes in lateral acceleration, providing immediate feedback to the control unit. This enables the system to quickly and accurately respond to dynamic driving conditions such as sharp turns, sudden lane changes, or uneven road surfaces. The use of accelerometers further improves control over optimal stability by continuously monitoring and adjusting the wheel positions to counteract lateral forces.

[0045] Preferably, the control unit is configured to adjust the first lateral adjustment mechanism and the second lateral adjustment mechanism based on gyroscopes measuring lateral forces acting on the vehicle. Gyroscopes are particularly effective in detecting rotational movements and angular velocity, providing comprehensive feedback on the vehicle orientation and stability. This allows the control unit to make more informed adjustments to the wheel positioning, especially in scenarios involving complex maneuvers or when the vehicle is subjected to rotational forces. The use of gyroscopes can enhance the system's ability to maintain stability during high-speed cornering or when navigating winding roads.BRIEF DESCRIPTION OF DRAWINGS

[0046] The invention is shown by means of example embodiments on a drawing, in which:

[0047] Figs. 1A, 1B and 1C show schematically a chassis assembly with the first embodiment of the suspension system in a top, front and side views;

[0048] Figs. 2A, 2B, 2C, 2D and 2E show schematically the chassis assembly with the first embodiment of the suspension system with different lateral wheel positions;

[0049] Figs. 3A and 3B show operation of the left-hand side of the first embodiment of the suspension system during transitions of the wheel between closer and farther positions;

[0050] Figs. 4A, 4B and 4C show the top, rear, and side views of a chassis assembly with a second embodiment of the suspension system;

[0051] Figs. 5A, 5B, 5C and 5D show show the chassis assembly with the second embodiment of the suspension system with different lateral wheel positions;

[0052] Figs. 6A and 6B show operation of the left-hand side of the second embodiment of the suspension system during transitions of the wheel between closer and farther positions;

[0053] Fig. 7 shows a functional diagram of the control system.

[0054] Figs. 8A, 8B and 8C show schematically a chassis assembly with the third embodiment of the suspension system in a top, front and side views;

[0055] Figs. 9A, 9B, 9C, 9D and 9E show schematically the chassis assembly with the third embodiment of the suspension system with different lateral wheel positions;

[0056] Figs. 10A and 10B show operation of the left-hand side of the third embodiment of the suspension system during transitions of the wheel between closer and farther positions;

[0057] Figs. 11 A, 11 B and 11 C show the top, rear, and side views of a chassis assembly with a fourth embodiment of the suspension system;

[0058] Figs. 12A, 12B, 12C and 12D show show the chassis assembly with the fourth embodiment of the suspension system with different lateral wheel positions;

[0059] Figs. 13A and 13B show operation of the left-hand side of the fourth embodiment of the suspension system during transitions of the wheel between closer and farther positions.DETAILED DESCRIPTION

[0060] The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense but is made merely for the purpose of illustrating the general principles of the invention.

[0061] A chassis assembly of a three-wheeled vehicle with a rear axle suspension system according to a first embodiment of the invention is shown in Figs. 1A-1C, 2A-2E and 3A-3B.

[0062] In Figs. 1A-1C the suspension system is shown with both rear wheels located at the same distance from the vehicle longitudinal axis in a top view (Fig. 1A), front view (Fig. 1B, which indicates the state of equilibrium between the forces exerted by contact of the two rear wheels with the ground and the resulting upright position of the vehicle body) and side view (Fig. 1C).

[0063] The suspension system is shown with the left-hand side rear wheel located closer to the vehicle longitudinal axis and the right-hand side rear wheel located further away from the vehicle longitudinal axis in a top view in Fig. 2A and in a front view in Fig. 2B - indicating the state of lack of equilibrium between the forces exerted by contact of the two rear wheels with the ground resulting from unequal horizontal distances between the rear wheels and the position of the vehicle center of mass; it also indicates compression of the left-hand side resilient element and expansion of the right-hand side resilient element, resulting from the aforementioned lack of equilibrium.

[0064] The result of compression of the left-hand side resilient element and expansion of the right-hand side resilient element, in the form of a lift of the left-hand side rear wheel and lowering of the right-hand side rear wheel in relation to the vehicle body is shown in a front view in Fig. 2C, in a side view in Fig. 2E.

[0065] Fig. 2D shows schematically the lateral tilt of the vehicle body resulting from the lift of the left-hand side rear wheel and lowering of the right-hand side rear wheel in relation to the vehicle body, in a front view.

[0066] The operation of the left-hand side of the suspension system during the transition from a position located closer to the vehicle longitudinal axis to a position located further from the vehicle longitudinal axis is shown in Fig. 3A, and during the transition from a position located further from the vehicle longitudinal axis to a position located closer to the vehicle longitudinal axis is shown in Fig. 3B.The suspension system of the first embodiment, shown for a rear axle, can also be used equivalently for other types of vehicles, such as those where the suspension system is used for a front axle with adjustable lateral position of the front wheels.

[0067] The vehicle has a chassis load-carrying structure 1 to which a front axle and a rear axle are mounted. In the embodiment presented herein, the front axle has one front wheel 2, and the rear axle has a pair of rear wheels 11 L, 11 R. The lateral positions of these rear wheels relative to the vehicle longitudinal axis XO are adjustable in a continuum of intermediate positions between two extreme positions, independently for each wheel 11 L, 11 R. The term “independently” means that the first distance L1 of the first wheel 11 L may be adjusted to a different value than the second distance L2. The front axle can be a steering axle, and the front steering wheel 2 may be mounted on a motorcycle front fork wheel suspension assembly.

[0068] In another embodiment, the vehicle may comprise one rear wheel or a pair of rear wheels that are steering wheels and a pair of front wheels with adjustable lateral positions (distances from the vehicle longitudinal axis XO).

[0069] Fig. 7 presents a functional diagram of the control system. The following description will present its functionality with respect to the first embodiment. This diagram delineates the interplay between the control unit, various sensors, actuators, and the mechanical components responsible for adjusting the lateral positions of the wheels to enhance vehicle stability. A control unit C processes inputs from multiple sensors and issues commands to the actuators to adjust the wheel positions accordingly. The sensors involved include a velocity sensor VS that measures the vehicle speed, a steering wheel sensor SWS that detects the steering wheel turn radius, and position sensors SL, SR that monitor the angular positions of the pivot mechanisms and trailing arms, providing feedback to the control unit.

[0070] The actuators in the system consist of toe angle control actuators 15L, 15R and trailing arm position control actuators 18L, 18R. The toe angle control actuators 15L, 15R adjust the toe angles of the wheels by manipulating the steering knuckles, while the trailing arm position control actuators 18L, 18R modify the lateral positions of the trailing arms, thereby altering the distances L1, L2 of the wheels from the vehicle longitudinal axis.

[0071] The mechanical linkages include the first and second wheel assemblies 9L, 9R, which comprise the wheels 11 L, 11 R and are connected to the vehicle chassisthrough pivot mechanisms 8L, 8R. These pivot mechanisms enable the wheel assemblies to pivot about both vertical Z1L, Z1R and horizontal axes under the control of the actuators. The steering knuckles 13L, 13R serve as the connection points for the wheels to the trailing arms and are directly controlled by the toe angle control actuators.

[0072] The system may operate in a feedback loop. The position sensors SL, SR continuously monitor the positions of the trailing arms and wheels, sending real-time data back to the control unit. The control unit processes the data received from the velocity and steering sensors VS, SWS, calculates the necessary adjustments for wheel stability, and sends appropriate commands to the actuators. These actuators then adjust the toe angles and thereby lateral positions of the wheels, optimizing the vehicle stability based on the current driving conditions.

[0073] Interconnections between all components are facilitated through control and data lines, ensuring real-time communication and adjustments. The control unit serves as the central hub, orchestrating the actions of sensors and actuators to dynamically adjust the vehicle lateral stability in response to driving dynamics.

[0074] With reference to the first embodiment of the suspension system, the vehicle comprises a first wheel assembly 9L connected to a vehicle chassis load-carrying structure 1 via a first pivot mechanism 8L pivotable about a first horizontal axis Y1L and about a first vertical axis Z1L, and a second wheel assembly 9R connected to the vehicle chassis load-carrying structure 1 via a second pivot mechanism 8R pivotable about a second horizontal axis Y1R and about a second vertical axis Z1R. The first wheel assembly 9L comprises a first wheel 11 L and is positioned on a first side of a vehicle longitudinal axis XO, and the second wheel assembly 9R comprises a second wheel 11 R and is positioned on a second side of the vehicle longitudinal axis XO opposite to the first side. The variable track width vehicle with a lateral stability control system further comprises a first lateral adjustment mechanism 7L for adjusting a first distance L1 of the first wheel 11 L with respect to the vehicle longitudinal axis XO and a second lateral adjustment mechanism 7R for adjusting a second distance L2 of the second wheel 11 R with respect to the vehicle longitudinal axis XO, wherein the first distance L1 is adjustable to a different value than the second distance L2. The variable track width vehicle with a lateral stability control system further comprises the control unit C for controlling the first lateral adjustment mechanism 7L and the second lateral adjustment mechanism 7R based on thevelocity of the vehicle detected by the velocity sensor VS and the steering wheel turn radius detected by the steering wheel sensor SWS.

[0075] The distance L1 is correlated with the angular position of the first pivot mechanism 8L about the first vertical axis Z1L, which is determined by a first sensor SL that generates a first sensor signal sL. The distance L2 is correlated with the angular position of the second pivot mechanism 8R about the second vertical axis Z1R, which is determined by a second sensor SR that generates a second sensor signal sR.

[0076] The lateral adjustment mechanisms 7L, 7R are controlled using a method by specifying the target distances L1, L2 at which the wheels shall be positioned, and subsequently controlling the lateral adjustment mechanisms 7L, 7R to move the corresponding wheel 11 L, 11 R either towards or away from the vehicle longitudinal axis XO, wherein the method checks whether the target distance has been achieved by analyzing the corresponding first or second sensor signal sL, sR.

[0077] The lateral stability control system, by changing the distances L1, L2 of the wheels 11 L, 11 R with respect to the vehicle longitudinal axis XO, adjusts the load distribution between the respective wheels 11 L, 11 R in order to enhance the vehicle lateral stability, particularly during vehicle movement on a curved path, inclined surface, or under side wind conditions. Specifically, the lateral stability control system operates to move the wheel 11 L, 11 R, which is less loaded, closer to the vehicle longitudinal axis XO.

[0078] The first pivot mechanism 8L may comprise a first trailing arm 10L having its first end connected to the vehicle chassis load-carrying structure 1 such that it is pivotable about the first horizontal axis Y1L and about the first vertical axis Z1L and having its second end connected to the first wheel 11 L by means of a first steering knuckle 13L such that the first wheel 11 L is turnable about a third vertical axis Z2L.

[0079] The second pivot mechanism 8R may comprise a second trailing arm 10R having its first end connected to the vehicle chassis load-carrying structure 1 such that it is pivotable about the second horizontal axis Y1R and about the second vertical axis Z1R and having its second end connected to the second wheel 11 R by means of a second steering knuckle 13R such that the second wheel 11 R is turnable about a fourth vertical axis Z2R.

[0080] The first lateral adjustment mechanism 7L may comprise a first toe angle control mechanism 6L for adjusting the turn angle of the first steering knuckle 13Labout the third vertical axis Z2L and the second lateral adjustment mechanism 7R may comprise a second toe angle control mechanism 6R for adjusting the second steering knuckle 13R about the fourth vertical axis Z2R, wherein the angle of the first steering knuckle 13L is adjustable to a different value than the angle of the second steering knuckle 13R. Therefore, the angle of the first steering knuckle 13L and the second steering knuckle 13R may be adjusted independently.

[0081] The control unit C is configured to control the operation of the first toe angle control mechanism 6L and the second toe angle control mechanism 6R.

[0082] The first pivot mechanism 8L may comprise a first spring element 24L connected on its first end to the vehicle load-carrying structure 1 and capable of restraining the vertical movement of the first wheel 11 L.

[0083] The second pivot mechanism 8R may comprise a second spring element 24R connected on its first end to the vehicle load-carrying structure 1 and capable of restraining the vertical movement of the second wheel 11 R.

[0084] This embodiment, as well as the other embodiments, present spring elements 24L, 24R as an example of a resilient element. Another form of the resilient element can be a push rod of a fixed length connected to a flexible element such as a torsion bar.

[0085] As explained above, the first rear wheel 11 L is mounted on the first steering knuckle 13L. The first steering knuckle 13L is mounted on the first end of the first trailing arm 10L using a joint 12L, such that the first steering knuckle 13L can be rotated about the third vertical axis Z2L, as indicated in Fig. 1B, 1C.

[0086] The second rear wheel 11 R is mounted on the second steering knuckle 13R. The second steering knuckle 13R is mounted on the first end of the second trailing arm 10R using a joint 12R, such that the second steering knuckle 13R can be rotated about the fourth vertical axis Z2R.

[0087] Furthermore, the first pivot mechanism 8L may comprise a first yoke element 23L, connected to the chassis load-carrying structure 1 , preferably by means of a joint 21 L, such that it is pivotable about the first horizontal axis Y1L, wherein the second end of the first trailing arm 10L is connected to the first yoke element 23L, preferably using a joint 20L, such that the first trailing arm 10L is pivotable about the first vertical axis Z1 L.

[0088] Thus, the rotating movement of the first yoke element 23L about the first horizontal axis Y1 L is restrained by the first spring element 24L, connected by a joint22AL to the first yoke element 23L and by a joint 22BL to the vehicle load-carrying structure 1.

[0089] The first toe angle control mechanism 6L may have the form of a first toe angle control actuator 15L having its first end connected to the first steering knuckle 13L, its second end connected to the first trailing arm 10L and capable of controlling the angular position of the first steering knuckle 13L. Thus, the rotating movement of the first steering knuckle 13L about the third vertical axis Z2L is governed by the first toe angle control actuator 15L. The first end of the first toe angle control actuator 15L is connected to the first steering knuckle 13L by a joint 14L. The second end of the first toe angle control actuator 15L is connected to the first trailing arm 10L by a joint 16L.

[0090] The first lateral adjustment mechanism 7L may comprise a first trailing arm position control actuator 18L for adjusting the lateral position of the first trailing arm 10L with respect to the vehicle longitudinal axis XO.

[0091] Thus, the rotating movement of the first trailing arm 10L about the first vertical axis Z1L is controlled by the first trailing arm position control actuator 18L. The first end of the first trailing arm position control actuator 18L is connected to the first trailing arm 10L by a joint 17L. The second end of the first trailing arm position control actuator 18L is connected to the first yoke element 23L by a joint 19L.

[0092] The second pivot mechanism 8R may comprise a second yoke element 23R, connected to the chassis load-carrying structure 1 , preferably by means of a joint 21 R, such that it is pivotable about the second horizontal axis Y1R. The second end of the second trailing arm 10R is connected to the second yoke element 23R, preferably by means of a joint 20R, such that the second trailing arm 10R is pivotable about the second vertical axis Z1 R.

[0093] The rotating movement of the second yoke element 23R about the second horizontal axis Y1R is restrained by a second spring element 24R, connected by a joint 22AR to the second yoke element 23R and by a joint 22BR to the chassis loadcarrying structure 1.

[0094] The second toe angle control mechanism 6R may have the form of a second toe angle control actuator 15R, with its first end connected to the second steering knuckle 13R, its second end connected to the second trailing arm 10R and capable of controlling the angular position of the second steering knuckle 13R. The rotating movement of the second steering knuckle 13R about the fourth vertical axis Z2R is controlled by the second toe angle control actuator 15R. The first end of the secondtoe angle control actuator 15R is connected to the second steering knuckle 13R by a joint 14R. The second end of the second toe angle control actuator 15R is connected to the second trailing arm 10R by a joint 16R.

[0095] The second lateral adjustment mechanism 7R may comprise a second trailing arm position control actuator 18R for adjusting the lateral position of the second trailing arm 10R with respect to the vehicle longitudinal axis XO. The rotational movement of the second trailing arm 10R about the second vertical axis Z1R is controlled by the second trailing arm position control actuator 18R. The first end of the second trailing arm position control actuator 18R is connected to the second trailing arm 10R by a joint 17R. The second end of the second trailing arm position control actuator 18R is connected to the second yoke element 23R by a joint 19R.

[0096] The control unit (C) may be configured to govern, for example, electronically the position and operation of the toe angle control actuators (15L, 15R) and the trailing arm position control actuators (18L, 18R). The control unit (C) is configured to acquire signals from sensors (SL, SR) detecting the angular position of the pivot mechanisms (8L, 8R) about the vertical axes (Z1 L, Z1 R), particularly for detecting the angular position of the trailing arms (10L, 10R) about the vertical axes (Z1L, Z1R). The sensors (SL, SR) may be potentiometric rotary sensors. The control unit (C) may also be configured to acquire signals from accelerometers or gyroscopes installed on the vehicle, which measure lateral forces acting on the vehicle. The lateral forces or accelerations acting on the vehicle may result from different combinations of vehicle speeds and radii of its driving trajectory, road camber, as well as various crosswind situations.

[0097] Figure 3A schematically shows the principles of operation of the rear suspension system while transitioning from a position where the first rear wheel 11 L is located closer to the vehicle longitudinal axis XO to a position where the first rear wheel 11 L is located further away from the vehicle longitudinal axis XO. For clarity, only the left-hand side of the suspension system has been depicted; however, the right-hand side operates under the same principle.

[0098] The transition takes place while the vehicle is in motion and is governed by the control unit C, working according to a predefined algorithm capable of precisely controlling the operation of the first toe angle control actuator 15L and the first trailing arm position control actuator 18L. To initiate the transition, the first toe angle control actuator 15L is commanded by the control unit C to contract to a preset length. As aresult, the toe angle of the first rear wheel 11 L takes a negative (toe-out) value. Simultaneously, the first trailing arm position control actuator 18L is commanded by the control unit C to start expanding. Consequently, a lateral outbound force FY1 is created due to the negative toe angle and the rotation of the first rear wheel 11 L as the vehicle moves forward. This force FY1 aims to move the first rear wheel 11 L further away from the vehicle longitudinal axis XO. As the first trailing arm position control actuator 18L expands, the first rear wheel 11 L is moved further away from the vehicle longitudinal axis XO. Once the desired position is reached, the first trailing arm position control actuator 18L is commanded by the control unit C to stop its expansion.

[0099] Figure 3B schematically shows the principles of operation of the rear suspension system while transitioning from a position where the first rear wheel 11 L is located further from the vehicle longitudinal axis XO to a position where the first rear wheel 11 L is located closer to the vehicle longitudinal axis XO. For clarity, only the left-hand side of the suspension system has been depicted; however, the righthand side operates under the same principle.

[0100] The transition takes place while the vehicle is in motion. To initiate the transition, the first toe angle control actuator 15L is commanded by the control unit C to expand to a preset length. As a result, the toe angle of the first rear wheel 11 L takes a positive (toe-in) value. Simultaneously, the first trailing arm position control actuator 18L is commanded by the control unit C to start contracting. Consequently, a lateral inbound force FY2 is created due to the positive toe angle and the rotation of the first rear wheel 11 L as the vehicle moves forward. This force FY2 aims to move the first rear wheel 11 L closer to the vehicle longitudinal axis XO. As the first trailing arm position control actuator 18L contracts, the first rear wheel 11 L is moved closer to the vehicle longitudinal axis XO. Once the desired position is reached, the first trailing arm position control actuator 18L is commanded by the control unit C to stop its contraction. The aforementioned mechanisms and principles are also applicable to vehicles comprising one, or a pair a pair of rear wheels and a pair of front wheels with adjustable lateral positions (distances from the vehicle longitudinal axis XO). In other words, the lateral stability control system may be applied to the front wheels.A chassis assembly of a three-wheeled vehicle with a rear axle suspension system according to a second embodiment of the invention is shown in Figs. 4A-4C, 5A-5E and 6A-6B.

[0101] In Figs. 4A-4C the suspension system is shown with both rear wheels located at equal distances from the vehicle longitudinal axis in a top view (Fig. 4A), front view (Fig. 4B, which indicates the state of equilibrium between the forces exerted by contact of the two rear wheels with the ground and the resulting upright position of the vehicle body) and side view (Fig. 4C).

[0102] The suspension system is shown with the left-hand side wheel located closer to the vehicle longitudinal axis and the right-hand wheel located further away from the vehicle longitudinal axis in a top view in Fig. 5A and in a rear view in Fig. 5B -indicating the state of lack of equilibrium between the forces exerted by contact of the two rear wheels with the ground resulting from unequal horizontal distances between the rear wheels and the position of the vehicle center of mass; it also indicates compression of the left-hand side spring element and expansion of the right-hand side spring element, resulting from the aforementioned lack of equilibrium. Further, it also indicates a rotation of the of the rotary element to the right, resulting from righthand side rear wheel being moved further away from the longitudinal axis of the vehicle than the left-hand side rear wheel and subsequently causing the left-hand side rear wheel to be lifted further upwards in relation to the vehicle’s body.

[0103] The lateral tilt of the vehicle as a result of lowering of the right-hand side rear wheel and lift of the left-hand side of the rear wheel of the vehicle, themselves resulting from compression of the left-hand side spring element and expansion of the right-hand side spring element, combined with the rotation of the rotating element, is shown in Fig. 5C in a rear view.

[0104] Fig. 5D shows schematically the lateral tilt of the vehicle body resulting from the lift of the left-hand side rear wheel and lowering of the right-hand side rear wheel in relation to the vehicle body, in a side view.

[0105] The operation of the left-hand side of an embodiment of the suspension system during the transition from a position located closer to the vehicle longitudinal axis to a position located further from the vehicle longitudinal axis is shown schematically in Fig. 6A and during the transition from a position located further from the vehicle longitudinal axis to a position located closer to the vehicle longitudinal axis is shown in Fig. 6B.The suspension system of the second embodiment, shown for a rear axle, can also be used equivalently for other types of vehicles, such as those where the suspension system is used for a front axle with variable track width wheels.

[0106] The vehicle has a chassis load-carrying structure 1 to which a front axle and a rear axle are mounted. In the embodiment presented herein, the front axle has one front wheel 2, and the rear axle has a pair of rear wheels 11 L, 11 R. The lateral positions of these rear wheels relative to the vehicle longitudinal axis XO are adjustable in a continuum of intermediate positions between two extreme positions, independently for each wheel 11 L, 11 R. The term “independently” means that the first distance L1 of the first wheel 11 L may be adjusted to a different value than the second distance L2. The front axle can be a steering axle, and the front steering wheel 2 may be mounted on a motorcycle front fork wheel suspension assembly.

[0107] In another embodiment, the vehicle may comprise one rear wheel, or a pair of rear wheels and a pair of front wheels with adjustable lateral positions (distances from the vehicle longitudinal axis XO).

[0108] The following description will present the functionality of the control system, as shown in Fig. 7, with respect to the second embodiment. In general, the control system operates as described with respect to the first embodiment, with the following differences. The mechanical linkages include the first and second wheel assemblies 9L, 9R, which comprise the wheels 11 L, 11 R and are connected to the vehicle chassis through pivot mechanisms 8L, 8R. These pivot mechanisms enable the wheel assemblies to pivot about vertical axes Z1L, Z1R under the control of the actuators and horizontal axes Y1L, Y1R restrained by spring elements 25L, 25R. The steering knuckles 13L, 13R serve as the connection points for the wheels to the trailing arms and are directly controlled by the toe angle control actuators 15L, 15R.

[0109] The first pivot mechanism 8L may comprise a first spring element 25L connected on its first end to the first trailing arm 10L by means of a joint 26L and its second end connected to a rotating element 28 by means of a joint 27L.

[0110] The second pivot mechanism 8R may comprise a second spring element 25R connected on its first end to the second trailing arm 10R by means of a joint 26R and its second end connected to a rotating element 28 by means of a joint 27R.

[0111] The rotating element 28 is connected to the vehicle load-carrying structure 1 using a joint 29 and capable of rotating around a substantially horizontal axis X1 , parallel to the vehicle’s longitudinal axis.As explained above, the first rear wheel 11 L is mounted on the first steering knuckle 13L. The first steering knuckle 13L is mounted on the first end of the first trailing arm 10L using a joint 12L, such that the first steering knuckle 13L can be rotated about the third vertical axis Z2L, as indicated in Fig. 4C.

[0112] The rotating movement of the first yoke element 23L about the first horizontal axis Y1L is restrained by the first spring element 25L, connected by means of a joint 26L to the first trailing arm 10L and by a joint 27L to the rotating element 28, which in turn is connected by a joint 29 to the vehicle load-carrying structure 1.

[0113] The rotating movement of the second yoke element 23R about the second horizontal axis Y1R is restrained by the first spring element 25R, connected by means of a joint 26R to the second trailing arm 10R and by a joint 27R to the rotating element 28, which in turn is connected by a joint 29 to the vehicle load-carrying structure 1.

[0114] Figure 6A schematically shows the principles of operation of the rear suspension system while transitioning from a position where the first rear wheel 11 L is located closer to the vehicle longitudinal axis XO to a position where the first rear wheel 11 L is located further away from the vehicle longitudinal axis XO. For clarity, only the left-hand side of the suspension system has been depicted; however, the right-hand side operates under the same principle.

[0115] The transition takes place while the vehicle is in motion and is governed by the control unit C, working according to a predefined algorithm capable of precisely controlling the operation of the first toe angle control actuator 15L and the first trailing arm position control actuator 18L. To initiate the transition, the first toe angle control actuator 15L is commanded by the control unit C to contract to a preset length. As a result, the toe angle of the first rear wheel 11 L takes a negative (toe-out) value. Simultaneously, the first trailing arm position control actuator 18L is commanded by the control unit C to start expanding. Consequently, a lateral outbound force FY1 is created due to the negative toe angle and the rotation of the first rear wheel 11 L as the vehicle moves forward. This force FY1 aims to move the first rear wheel 11 L further away from the vehicle longitudinal axis XO. As the first trailing arm position control actuator 18L expands, the first rear wheel 11 L is moved further away from the vehicle longitudinal axis XO. Lateral outbound movement of the wheel 11 L causes outbound movement of the joint 26L. That movement is further transmitted through spring element 25L and joint 27L onto the rotary element 28 and subsequentlyconverted into counterclockwise (as seen from the rear) rotation of the rotary element 28. That rotation move is subsequently translated with intermediation of joint 27R, spring element 25R and joint 26R into vertical upward movement of the wheel 11 R, whose lateral distance from the vehicle’s longitudinal axis XO remains constant. Once the desired position is reached, the first trailing arm position control actuator 18L is commanded by the control unit C to stop its expansion.

[0116] Figure 6B schematically shows the principles of operation of the rear suspension system while transitioning from a position where the first rear wheel 11 L is located further from the vehicle longitudinal axis XO to a position where the first rear wheel 11 L is located closer to the vehicle longitudinal axis XO. For clarity, only the left-hand side of the suspension system has been depicted; however, the righthand side operates under the same principle.

[0117] The transition takes place while the vehicle is in motion. To initiate the transition, the first toe angle control actuator 15L is commanded by the control unit C to expand to a preset length. As a result, the toe angle of the first rear wheel 11 L takes a positive (toe-in) value. Simultaneously, the first trailing arm position control actuator 18L is commanded by the control unit C to start contracting. Consequently, a lateral inbound force FY2 is created due to the positive toe angle and the rotation of the first rear wheel 11 L as the vehicle moves forward. This force FY2 aims to move the first rear wheel 11 L closer to the vehicle longitudinal axis XO. As the first trailing arm position control actuator 18L contracts, the first rear wheel 11 L is moved closer to the vehicle longitudinal axis XO. Lateral inbound movement of the wheel 11 L causes inbound movement of the joint 26L. That movement is further transmitted through spring element 25L and joint 27L onto the rotary element 28 and subsequently converted into clockwise (as seen from the rear) rotation of the rotary element 28. That rotation move is subsequently translated with intermediation of joint 27R, spring element 25R and joint 26R into vertical downward movement of the wheel 11 R, whose lateral distance from the vehicle’s longitudinal axis XO remains constant. Once the desired position is reached, the first trailing arm position control actuator 18L is commanded by the control unit C to stop its contraction.

[0118] A chassis assembly of a three-wheeled vehicle with a rear axle suspension system according to a third embodiment of the invention is shown in Figs. 8A-8C, 9A-9D and 10A-10B.In Figs. 8A-8C the suspension system is shown with both rear wheels located at the same distance from the vehicle longitudinal axis in a top view (Fig. 8A), front view (Fig. 8B, which indicates the upright position of the vehicle body) and side view (Fig. 8C).

[0119] The suspension system is shown with the left-hand side rear wheel located closer to the vehicle longitudinal axis and the right-hand side rear wheel located further away from the vehicle longitudinal axis in a top view in Fig. 9A and in a rear view in Fig. 9B - indicating the vertical displacement of the right-hand side wheel complementing its lateral movement away from the vehicle’s longitudinal axis.

[0120] The result of lift of the right-hand side wheel in relation to the vehicle body is shown in a rear view in Fig. 9C, in a side view in Fig. 9D.

[0121] The operation of the left-hand side of the suspension system during the transition from a position located closer to the vehicle longitudinal axis to a position located further from the vehicle longitudinal axis is shown in Fig. 10A, and during the transition from a position located further from the vehicle longitudinal axis to a position located closer to the vehicle longitudinal axis is shown in Fig. 10B.

[0122] The suspension system of the third embodiment, shown for a rear axle, can also be used equivalently for other types of vehicles, such as those where the suspension system is used for a front axle with adjustable lateral position of the front wheels.

[0123] The vehicle has a chassis load-carrying structure 1 to which a front axle and a rear axle are mounted. In the third embodiment presented herein, the front axle has one front wheel 2, and the rear axle has a pair of rear wheels 11 L, 11 R. The lateral positions of these rear wheels relative to the vehicle longitudinal axis XO are adjustable in a continuum of intermediate positions between two extreme positions, independently for each wheel 11 L, 11 R. The term “independently” means that the first distance L1 of the first wheel 11 L may be adjusted to a different value than the second distance L2. The front axle can be a steering axle, and the front steering wheel 2 may be mounted on a motorcycle front fork wheel suspension assembly.

[0124] In another embodiment, the vehicle may comprise one rear wheel or a pair of rear wheels that are steering wheels and a pair of front wheels with adjustable lateral positions (distances from the vehicle longitudinal axis XO).

[0125] The following description will present the functionality of the control system, as shown in Fig. 7, with respect to the third embodiment. This diagram delineates theinterplay between the control unit, various sensors, actuators, and the mechanical components responsible for adjusting the lateral positions of the wheels to enhance vehicle stability. A control unit C processes inputs from multiple sensors and issues commands to the actuators to adjust the wheel positions accordingly. The sensors involved include a velocity sensor VS that measures the vehicle speed, a steering wheel sensor SWS that detects the steering wheel turn radius, and position sensors SL, SR that monitor the angular positions of the pivot mechanisms and trailing arms, providing feedback to the control unit.

[0126] The actuators in the system consist of toe angle control actuators 15L, 15R and trailing arm position control actuators 18L, 18R. The toe angle control actuators 15L, 15R adjust the toe angles of the wheels by manipulating the steering knuckles, while the trailing arm position control actuators 18L, 18R modify the lateral positions of the trailing arms, thereby altering the distances L1, L2 of the wheels from the vehicle longitudinal axis.

[0127] The mechanical linkages include the first and second wheel assemblies 9L, 9R, which comprise the wheels 11 L, 11 R and are connected to the vehicle chassis through pivot mechanisms 8L, 8R. These pivot mechanisms enable the wheel assemblies to pivot about both vertical Z1 L, Z1 R and horizontal axes Y1 L, Y1 R under the control of the actuators. The steering knuckles 13L, 13R serve as the connection points for the wheels to the trailing arms and are directly controlled by the toe angle control actuators.

[0128] The system may operate in a feedback loop. The position sensors SL, SR continuously monitor the positions of the trailing arms and wheels, sending real-time data back to the control unit. The control unit processes the data received from the velocity and steering sensors VS, SWS, calculates the necessary adjustments for wheel stability, and sends appropriate commands to the actuators. These actuators then adjust the toe angles and thereby lateral positions of the wheels, optimizing the vehicle stability based on the current driving conditions.

[0129] Interconnections between all components are facilitated through control and data lines, ensuring real-time communication and adjustments. The control unit serves as the central hub, orchestrating the actions of sensors and actuators to dynamically adjust the vehicle lateral stability in response to driving dynamics.

[0130] With reference to the third embodiment of the suspension system, the vehicle comprises a first wheel assembly 9L connected to a vehicle chassis load-carryingstructure 1 via a first pivot mechanism 8L pivotable about a first horizontal axis Y1L and about a first vertical axis Z1L, and a second wheel assembly 9R connected to the vehicle chassis load-carrying structure 1 via a second pivot mechanism 8R pivotable about a second horizontal axis Y1R and about a second vertical axis Z1R. The first wheel assembly 9L comprises a first wheel 11 L and is positioned on a first side of a vehicle longitudinal axis XO, and the second wheel assembly 9R comprises a second wheel 11 R and is positioned on a second side of the vehicle longitudinal axis XO opposite to the first side. The variable track width vehicle with a lateral stability control system further comprises a first lateral adjustment mechanism 7L for adjusting a first distance L1 of the first wheel 11 L with respect to the vehicle longitudinal axis XO and a second lateral adjustment mechanism 7R for adjusting a second distance L2 of the second wheel 11 R with respect to the vehicle longitudinal axis XO, wherein the first distance L1 is adjustable to a different value than the second distance L2. The variable track width vehicle with a lateral stability control system further comprises the control unit C for controlling the first lateral adjustment mechanism 7L and the second lateral adjustment mechanism 7R based on the velocity of the vehicle detected by the velocity sensor VS and the steering wheel turn radius detected by the steering wheel sensor SWS.

[0131] The distance L1 is correlated with the angular position of the first pivot mechanism 8L about the first vertical axis Z1L, which is determined by a first sensor SL that generates a first sensor signal sL. The distance L2 is correlated with the angular position of the second pivot mechanism 8R about the second vertical axis Z1R, which is determined by a second sensor SR that generates a second sensor signal sR.

[0132] The lateral adjustment mechanisms 7L, 7R are controlled using a method by specifying the target distances L1, L2 at which the wheels shall be positioned, and subsequently controlling the lateral adjustment mechanisms 7L, 7R to move the corresponding wheel 11 L, 11 R either towards or away from the vehicle longitudinal axis XO, wherein the method checks whether the target distance has been achieved by analyzing the corresponding first or second sensor signal sL, sR.

[0133] The lateral stability control system, by changing the distances L1, L2 of the wheels 11 L, 11 R with respect to the vehicle longitudinal axis XO, exerts a lateral force onto the vehicle’s load carrying structure thus laterally displacing its center of mass, adjusts the vertical position of the wheels 11 L, 11 R in relation to the vehicle’s centerof mass and adjusts load distribution between the respective wheels 11 L, 11 R in order to enhance the vehicle lateral stability, particularly during vehicle movement on a curved path, inclined surface, or under side wind conditions. Specifically, the lateral stability control system operates to move the wheel 11 L, 11 R, which is less loaded, closer to the vehicle longitudinal axis XO.

[0134] The first pivot mechanism 8L may comprise a first trailing arm 10L having its first end connected to the vehicle chassis load-carrying structure 1 such that it is pivotable about the first horizontal axis Y1L and about the first vertical axis Z1L and having its second end connected to the first wheel 11 L by means of a first steering knuckle 13L such that the first wheel 11 L is turnable about a third vertical axis Z2L.

[0135] The second pivot mechanism 8R may comprise a second trailing arm 10R having its first end connected to the vehicle chassis load-carrying structure 1 such that it is pivotable about the second horizontal axis Y1R and about the second vertical axis Z1R and having its second end connected to the second wheel 11 R by means of a second steering knuckle 13R such that the second wheel 11 R is turnable about a fourth vertical axis Z2R.

[0136] The first lateral adjustment mechanism 7L may comprise a first toe angle control mechanism 6L for adjusting the turn angle of the first steering knuckle 13L about the third vertical axis Z2L and the second lateral adjustment mechanism 7R may comprise a second toe angle control mechanism 6R for adjusting the second steering knuckle 13R about the fourth vertical axis Z2R, wherein the angle of the first steering knuckle 13L is adjustable to a different value than the angle of the second steering knuckle 13R. Therefore, the angle of the first steering knuckle 13L and the second steering knuckle 13R may be adjusted independently.

[0137] The control unit C is configured to control the operation of the first toe angle control mechanism 6L and the second toe angle control mechanism 6R.

[0138] The first pivot mechanism 8L may comprise a first spring element 24L connected on its first end to the vehicle load-carrying structure 1 and capable of restraining the vertical movement of the first wheel 11 L.

[0139] The second pivot mechanism 8R may comprise a second spring element 24R connected on its first end to the vehicle load-carrying structure 1 and capable of restraining the vertical movement of the second wheel 11 R.

[0140] As explained above, the first rear wheel 11 L is mounted on the first steering knuckle 13L. The first steering knuckle 13L is mounted on the first end of the firsttrailing arm 10L using a joint 12L, such that the first steering knuckle 13L can be rotated about the third vertical axis Z2L, as indicated in Fig. 8B, 8C.

[0141] The second rear wheel 11 R is mounted on the second steering knuckle 13R. The second steering knuckle 13R is mounted on the first end of the second trailing arm 10R using a joint 12R, such that the second steering knuckle 13R can be rotated about the fourth vertical axis Z2R.

[0142] Furthermore, the first pivot mechanism 8L may comprise a first yoke element 23L, connected to the chassis load-carrying structure 1 , preferably by means of a joint 21 L, such that it is pivotable about the first horizontal axis Y1L, wherein the second end of the first trailing arm 10L is connected to the first yoke element 23L, preferably using a joint 20L, such that the first trailing arm 10L is pivotable about the first vertical axis Z1 L.

[0143] Thus, the rotating movement of the first yoke element 23L about the first horizontal axis Y1 L is restrained by the first spring element 24L, connected by a joint 22AL to the first trailing arm 10L and by a joint 22BL to the vehicle load-carrying structure 1.

[0144] The first toe angle control mechanism 6L may have the form of a first toe angle control actuator 15L having its first end connected to the first steering knuckle 13L, its second end connected to the first trailing arm 10L and capable of controlling the angular position of the first steering knuckle 13L. Thus, the rotating movement of the first steering knuckle 13L about the third vertical axis Z2L is governed by the first toe angle control actuator 15L. The first end of the first toe angle control actuator 15L is connected to the first steering knuckle 13L by a joint 14L. The second end of the first toe angle control actuator 15L is connected to the first trailing arm 10L by a joint 16L.

[0145] The first lateral adjustment mechanism 7L may comprise a first trailing arm position control actuator 18L for adjusting the lateral position of the first trailing arm 10L with respect to the vehicle longitudinal axis XO.

[0146] Thus, the rotating movement of the first trailing arm 10L about the first vertical axis Z1L is controlled by the first trailing arm position control actuator 18L. The first end of the first trailing arm position control actuator 18L is connected to the first trailing arm 10L by a joint 17L. The second end of the first trailing arm position control actuator 18L is connected to the first yoke element 23L by a joint 19L.

[0147] The second pivot mechanism 8R may comprise a second yoke element 23R, connected to the chassis load-carrying structure 1 , preferably by means of a joint21 R, such that it is pivotable about the second horizontal axis Y1R. The second end of the second trailing arm 10R is connected to the second yoke element 23R, preferably by means of a joint 20R, such that the second trailing arm 10R is pivotable about the second vertical axis Z1 R.

[0148] The rotating movement of the second yoke element 23R about the second horizontal axis Y1R is restrained by a second spring element 24R, connected by a joint 22AR to the second trailing arm 10R and by a joint 22BR to the chassis loadcarrying structure 1.

[0149] The second toe angle control mechanism 6R may have the form of a second toe angle control actuator 15R, with its first end connected to the second steering knuckle 13R, its second end connected to the second trailing arm 10R and capable of controlling the angular position of the second steering knuckle 13R. The rotating movement of the second steering knuckle 13R about the fourth vertical axis Z2R is controlled by the second toe angle control actuator 15R. The first end of the second toe angle control actuator 15R is connected to the second steering knuckle 13R by a joint 14R. The second end of the second toe angle control actuator 15R is connected to the second trailing arm 10R by a joint 16R.

[0150] The second lateral adjustment mechanism 7R may comprise a second trailing arm position control actuator 18R for adjusting the lateral position of the second trailing arm 10R with respect to the vehicle longitudinal axis XO. The rotational movement of the second trailing arm 10R about the second vertical axis Z1R is controlled by the second trailing arm position control actuator 18R. The first end of the second trailing arm position control actuator 18R is connected to the second trailing arm 10R by a joint 17R. The second end of the second trailing arm position control actuator 18R is connected to the second yoke element 23R by a joint 19R.

[0151] The control unit (C) may be configured to govern, for example, electronically the position and operation of the toe angle control actuators (15L, 15R) and the trailing arm position control actuators (18L, 18R). The control unit (C) is configured to acquire signals from sensors (SL, SR) detecting the angular position of the pivot mechanisms (8L, 8R) about the vertical axes (Z1 L, Z1 R), particularly for detecting the angular position of the trailing arms (10L, 10R) about the vertical axes (Z1L, Z1R). The sensors (SL, SR) may be potentiometric rotary sensors. The control unit (C) may also be configured to acquire signals from accelerometers or gyroscopes installed on the vehicle, which measure lateral forces acting on the vehicle. The lateral forces oraccelerations acting on the vehicle may result from different combinations of vehicle speeds and radii of its driving trajectory, road camber, as well as various crosswind situations.

[0152] Figure 10A schematically shows the principles of operation of the rear suspension system while transitioning from a position where the first rear wheel 11 L is located closer to the vehicle longitudinal axis XO to a position where the first rear wheel 11 L is located further away from the vehicle longitudinal axis XO. For clarity, only the left-hand side of the suspension system has been depicted; however, the right-hand side operates under the same principle.

[0153] The transition takes place while the vehicle is in motion and is governed by the control unit C, working according to a predefined algorithm capable of precisely controlling the operation of the first toe angle control actuator 15L and the first trailing arm position control actuator 18L. To initiate the transition, the first toe angle control actuator 15L is commanded by the control unit C to contract to a preset length. As a result, the toe angle of the first rear wheel 11 L takes a negative (toe-out) value. Simultaneously, the first trailing arm position control actuator 18L is commanded by the control unit C to start expanding. Consequently, a lateral outbound force FY1 is created due to the negative toe angle and the rotation of the first rear wheel 11 L as the vehicle moves forward. This force FY1 aims to move the first rear wheel 11 L further away from the vehicle longitudinal axis XO. As the first trailing arm position control actuator 18L expands, the first rear wheel 11 L is moved further away from the vehicle longitudinal axis XO. Once the desired position is reached, the first trailing arm position control actuator 18L is commanded by the control unit C to stop its expansion.

[0154] Figure 10B schematically shows the principles of operation of the rear suspension system while transitioning from a position where the first rear wheel 11 L is located further from the vehicle longitudinal axis XO to a position where the first rear wheel 11 L is located closer to the vehicle longitudinal axis XO. For clarity, only the left-hand side of the suspension system has been depicted; however, the righthand side operates under the same principle.

[0155] The transition takes place while the vehicle is in motion. To initiate the transition, the first toe angle control actuator 15L is commanded by the control unit C to expand to a preset length. As a result, the toe angle of the first rear wheel 11 L takes a positive (toe-in) value. Simultaneously, the first trailing arm position controlactuator 18L is commanded by the control unit C to start contracting. Consequently, a lateral inbound force FY2 is created due to the positive toe angle and the rotation of the first rear wheel 11 L as the vehicle moves forward. This force FY2 aims to move the first rear wheel 11 L closer to the vehicle longitudinal axis XO. As the first trailing arm position control actuator 18L contracts, the first rear wheel 11 L is moved closer to the vehicle longitudinal axis XO. Once the desired position is reached, the first trailing arm position control actuator 18L is commanded by the control unit C to stop its contraction. The aforementioned mechanisms and principles are also applicable to vehicles comprising one, or a pair a pair of rear wheels and a pair of front wheels with adjustable lateral positions (distances from the vehicle longitudinal axis XO). In other words, the lateral stability control system may be applied to the front wheels.

[0156] A chassis assembly of a three-wheeled vehicle with a rear axle suspension system according to a fourth embodiment of the invention is shown in Figs. 11A-11C, 12A-12E and 13A-13B.

[0157] In Figs. 11A-11C the suspension system is shown with both rear wheels located at equal distances from the vehicle longitudinal axis in a top view (Fig. 11 A), rear view (Fig. 11 B, which indicates the upright position of the vehicle body) and side view (Fig. 11 C).

[0158] The suspension system is shown with the left-hand side wheel located closer to the vehicle longitudinal axis and the right-hand wheel located further away from the vehicle longitudinal axis in a top view in Fig. 12A and in a rear view in Fig. 12B -indicating the vertical displacement of the right-hand side wheel complementing its lateral movement away from the vehicle’s longitudinal axis.

[0159] The result of lift of the right-hand side wheel in relation to the vehicle body is shown in a rear view in Fig. 12C, in a side view in Fig. 12E.

[0160] The operation of the left-hand side of an embodiment of the suspension system during the transition from a position located closer to the vehicle longitudinal axis to a position located further from the vehicle longitudinal axis is shown schematically in Fig. 13A and during the transition from a position located further from the vehicle longitudinal axis to a position located closer to the vehicle longitudinal axis is shown in Fig. 13B.

[0161] The suspension system of the fourth embodiment, shown for a rear axle, can also be used equivalently for other types of vehicles, such as those where the suspension system is used for a front axle with variable track width wheels.The vehicle has a chassis load-carrying structure 1 to which a front axle and a rear axle are mounted. In the fourth embodiment presented herein, the front axle has one front wheel 2, and the rear axle has a pair of rear wheels 11 L, 11 R. The lateral positions of these rear wheels relative to the vehicle longitudinal axis XO are adjustable in a continuum of intermediate positions between two extreme positions, independently for each wheel 11 L, 11 R. The term “independently” means that the first distance L1 of the first wheel 11 L may be adjusted to a different value than the second distance L2. The front axle can be a steering axle, and the front steering wheel 2 may be mounted on a motorcycle front fork wheel suspension assembly.

[0162] In another embodiment, the vehicle may comprise one rear wheel, or a pair of rear wheels and a pair of front wheels with adjustable lateral positions (distances from the vehicle longitudinal axis XO).

[0163] The following description will present the functionality of the control system, as shown in Fig. 7, with respect to the fourth embodiment. In general, the control system operates as described with respect to the third embodiment, with the following differences.

[0164] The mechanical linkages include the first and second wheel assemblies 9L, 9R, which comprise the wheels 11 L, 11 R and are connected to the vehicle chassis through pivot mechanisms 8L, 8R. These pivot mechanisms enable the wheel assemblies to pivot about vertical axes Z1L, Z1R under the control of the actuators and horizontal axes Y1L, Y1R restrained by spring elements 24L, 24R. The steering knuckles 13L, 13R serve as the connection points for the wheels to the trailing arms and are directly controlled by the toe angle control actuators 15L, 15R.

[0165] The lateral stability control system, by changing the distances L1, L2 of the wheels 11 L, 11 R with respect to the vehicle longitudinal axis XO, adjusts the load distribution between the respective wheels 11 L, 11 R in order to enhance the vehicle lateral stability, particularly during vehicle movement on a curved path, inclined surface, or under side wind conditions. Specifically, the lateral stability control system operates to move the wheel 11 L, 11 R, which is less loaded, closer to the vehicle longitudinal axis XO.

[0166] The first pivot mechanism 8L may comprise a first spring element 24L connected on its first end to the first steering knuckle 13L by means of a joint 22CL and its second end connected to the vehicle’s load carrying structure by means of a joint 22BL.The second pivot mechanism 8R may comprise a second spring element 24R connected on its first end to the second steering knuckle13R by means of a joint 22CR and its second end connected to the vehicle’s load carrying structure by means of a joint 22BR.

[0167] As explained above, the first rear wheel 11 L is mounted on the first steering knuckle 13L. The first steering knuckle 13L is mounted on the first end of the first trailing arm 10L using a joint 12L, such that the first steering knuckle 13L can be rotated about the third vertical axis Z2L, as indicated in Fig. 11 C.

[0168] The rotating movement of the first yoke element 23L about the first horizontal axis Y1L is restrained by the first spring element 24L, connected by means of a joint 22CL to the first steering knuckle 13L and by a joint 22BL to the vehicle load-carrying structure 1.

[0169] The first toe angle control mechanism 6L may have the form of a first toe angle control actuator 15L having its first end connected to the first steering knuckle 13L, second end connected to the yoke element 23L and capable of controlling the angular position of the first steering knuckle 13L. Thus, the rotating movement of the first steering knuckle 13L about the third vertical axis Z2L is governed by the first toe angle control actuator 15L. The first end of the first toe angle control actuator 15L is connected to the first steering knuckle 13L by a joint 26L. The second end of the first toe angle control actuator 15L is connected to the yoke element 23L by a joint 25L.

[0170] The rotating movement of the second yoke element 23R about the second horizontal axis Y1R is restrained by the first spring element 24R, connected by means of a joint 22CR to the second steering knuckle 13R and by a joint 22BR to the vehicle load-carrying structure 1.

[0171] The second toe angle control mechanism 6R may have the form of a second toe angle control actuator 15R, with its first end connected to the second steering knuckle 13R, its second end connected to the second yoke element 23R and capable of controlling the angular position of the second steering knuckle 13R. The rotating movement of the second steering knuckle 13R about the fourth vertical axis Z2R is controlled by the second toe angle control actuator 15R. The first end of the second toe angle control actuator 15R is connected to the second steering knuckle 13R by a joint 26R. The second end of the second toe angle control actuator 15R is connected to the second yoke element 23R by a joint 25R.Figure 13A schematically shows the principles of operation of the rear suspension system while transitioning from a position where the first rear wheel 11 L is located closer to the vehicle longitudinal axis XO to a position where the first rear wheel 11 L is located further away from the vehicle longitudinal axis XO. For clarity, only the left-hand side of the suspension system has been depicted; however, the right-hand side operates under the same principle.

[0172] The transition takes place while the vehicle is in motion and is governed by the control unit C, working according to a predefined algorithm capable of precisely controlling the operation of the first toe angle control actuator 15L and the first trailing arm position control actuator 18L. To initiate the transition, the first toe angle control actuator 15L is commanded by the control unit C to expand to a preset length. As a result, the toe angle of the first rear wheel 11 L takes a negative (toe-out) value. Simultaneously, the first trailing arm position control actuator 18L is commanded by the control unit C to start expanding. Consequently, a lateral outbound force FY1 is created due to the negative toe angle and the rotation of the first rear wheel 11 L as the vehicle moves forward. This force FY1 aims to move the first rear wheel 11 L further away from the vehicle longitudinal axis XO. As the first trailing arm position control actuator 18L expands, the first rear wheel 11 L is moved further away from the vehicle longitudinal axis XO. Lateral outbound movement of the wheel 11 L causes outbound movement of the joint 22CL. That movement is further transmitted through spring element 24L and joint 22BL onto the load carrying structure of the vehicle causing lateral outbound displacement of the vehicle’s center of mass to the left. Once the desired position is reached, the first trailing arm position control actuator 18L is commanded by the control unit C to stop its expansion.

[0173] Figure 13B schematically shows the principles of operation of the rear suspension system while transitioning from a position where the first rear wheel 11 L is located further from the vehicle longitudinal axis XO to a position where the first rear wheel 11 L is located closer to the vehicle longitudinal axis XO. For clarity, only the left-hand side of the suspension system has been depicted; however, the righthand side operates under the same principle.

[0174] The transition takes place while the vehicle is in motion. To initiate the transition, the first toe angle control actuator 15L is commanded by the control unit C to contract to a preset length. As a result, the toe angle of the first rear wheel 11 L takes a positive (toe-in) value. Simultaneously, the first trailing arm position controlactuator 18L is commanded by the control unit C to start contracting. Consequently, a lateral inbound force FY2 is created due to the positive toe angle and the rotation of the first rear wheel 11 L as the vehicle moves forward. This force FY2 aims to move the first rear wheel 11 L closer to the vehicle longitudinal axis XO. As the first trailing arm position control actuator 18L contracts, the first rear wheel 11 L is moved closer to the vehicle longitudinal axis XO. Lateral inbound movement of the wheel 11 L causes inbound movement of the joint 22CL. That movement is further transmitted through spring element 24L and joint 22BL onto the load carrying structure of the vehicle causing lateral inbound displacement of the vehicle’s center of mass to the right. Once the desired position is reached, the first trailing arm position control actuator 18L is commanded by the control unit C to stop its contraction.

[0175] The aforementioned mechanisms and principles are also applicable to vehicles comprising a single, or a pair of rear wheels and a pair of front wheels with adjustable lateral positions.

[0176] While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications, and other applications of the invention may be made. Therefore, the claimed invention as recited in the claims that follow is not limited to the embodiments described herein.

Claims

CLAIMS1. A variable track width vehicle with a lateral stability control system, the vehicle comprising:- a first wheel assembly (9L) connected to a vehicle chassis load-carrying structure (1) and comprising a first wheel (11 L) positioned on a first side of a vehicle longitudinal axis (XO);- a second wheel assembly (9R) connected to the vehicle chassis load-carrying structure (1) and comprising a second wheel (11 R) positioned on a second side of the vehicle longitudinal axis (XO) opposite to the first side;- a first lateral adjustment mechanism (7L) for adjusting a first distance (L1) of the first wheel (11 L) with respect to the vehicle longitudinal axis (XO);- a second lateral adjustment mechanism (7R) for adjusting a second distance (L2) of the second wheel (11 R) with respect to the vehicle longitudinal axis (XO);- wherein the first distance (L1) is adjustable to a different value than the second distance (L2);- wherein the first wheel assembly (9L) is connected to the vehicle chassis loadcarrying structure (1) via a first pivot mechanism (8L) pivotable about a first vertical axis (Z1 L) and further comprises a first pivot sensor (PSL) for generating a first pivot signal (psL) corresponding to a pivot angle of the first pivot mechanism (8L) about the first vertical axis (Z1L), wherein the first distance (L1) is determined as a function of a pivot of the first wheel assembly (9L) about the first vertical axis (Z1 L);- wherein the second wheel assembly (9R) is connected to the vehicle chassis load-carrying structure (1) via a second pivot mechanism (8R) pivotable about a second vertical axis (Z1 R) and further comprises a second pivot sensor (PSR) for generating a second pivot signal (psR) corresponding to a pivot angle of the second pivot mechanism (8R) about the second vertical axis (Z1 R), wherein the second distance (L2) is determined as a function of a pivot of the second wheel assembly (9R) about the second vertical axis (Z1 R);- wherein the first pivot mechanism (8L) comprises a first trailing arm (10L) having its first end connected to the vehicle chassis load-carrying structure (1) such that it is pivotable about a first horizontal axis (Y1L) and about the first vertical axis (Z1L) and having its second end connected to the first wheel (11 L) by means of afirst steering knuckle (13L) such that the first wheel (11 L) is turnable about a third vertical axis (Z2L);- wherein the second pivot mechanism (8R) comprises a second trailing arm (10R) having its first end connected to the vehicle chassis load-carrying structure (1) such that it is pivotable about a second horizontal axis (Y1R) and about the second vertical axis (Z1 R) and having its second end connected to the second wheel (11 R) by means of a second steering knuckle (13R) such that the second wheel (11 R) is turnable about a fourth vertical axis (Z2R);- wherein the first lateral adjustment mechanism (7L) comprises a first trailing arm position control actuator (18L) for adjusting the lateral position of the first trailing arm (10L) with respect to the vehicle longitudinal axis (XO);- wherein the second lateral adjustment mechanism (7R) comprises a second trailing arm position control actuator (18R) for adjusting the lateral position of the second trailing arm (10R) with respect to the vehicle longitudinal axis (XO);- wherein the lateral position of the first trailing arm (1 OL) with respect to the vehicle longitudinal axis (XO) is adjustable to a different value than the lateral position of the second trailing arm (10R) with respect to the vehicle longitudinal axis (XO); - wherein the first pivot mechanism (8L) comprises a first resilient element (24L) connected on its first end to the vehicle load-carrying structure (1) and capable of restraining the vertical movement of the first wheel (11 L);- wherein the second pivot mechanism (8R) comprises a second resilient element (24R) connected on its first end to the vehicle load-carrying structure (1) and capable of restraining the vertical movement of the second wheel (11 R); and - a control unit (C) configured to:- control the first lateral adjustment mechanism (7L) and the second lateral adjustment mechanism (7R) based on the first pivot signal (psL) and the second pivot signal (psR); and- adjust the distances (L1 , L2) by controlling the operation of the first toe angle control mechanism (6L) and the second toe angle control mechanism (6R).

2. The vehicle according to claim 1, wherein the control unit (C) is configured to adjust the first lateral adjustment mechanism (7L) and the second lateral adjustment mechanism (7R) based on readings of the vehicle velocity detected by a velocitysensor (VS) and a turn radius of a steering wheel detected by a steering wheel sensor (SWS).

3. The vehicle according to claim 1 or 2, wherein:- the first lateral adjustment mechanism (7L) comprises a first toe angle control mechanism (6L) for adjusting the turn angle of the first steering knuckle (13L) about the third vertical axis (Z2L); and- the second lateral adjustment mechanism (7R) comprises a second toe angle control mechanism (6R) for adjusting the second steering knuckle (13R) about the fourth vertical axis (Z2R).

4. The vehicle according to claim 3, wherein:- the first toe angle control mechanism (6L) comprises a first toe angle control actuator (15L) with its first end connected to the first steering knuckle (13L) and capable of controlling the angular position of the first steering knuckle (13L);- the second toe angle control mechanism (6R) comprises a second toe angle control actuator (15R) with its first end connected to the second steering knuckle (13R) and capable of controlling the angular position of the second steering knuckle (13R).

5. The vehicle according to claim 4, wherein:- the first toe angle control mechanism (6L) comprises a first toe angle control actuator (15L) with its second end connected to the first yoke element (23L) and capable of controlling the angular position of the first steering knuckle (13L);- the second toe angle control mechanism (6R) comprises a second toe angle control actuator (15R) with its second end connected to the second yoke element (23R) and capable of controlling the angular position of the second steering knuckle (13R).

6. The vehicle according to claim 1 , wherein:- the first pivot mechanism (8L) comprises a first yoke element (23L) connected to the chassis load-carrying structure (1) such that it is pivotable about the first horizontal axis (Y1L), wherein the second end of the first trailing arm (10L) isconnected to the first yoke element (23L) such that the first trailing arm (10L) is pivotable about the first vertical axis (Z1 L);- the second pivot mechanism (8R) comprises a second yoke element (23R) connected to the chassis load-carrying structure (1) such that it is pivotable about the second horizontal axis (Y1R), wherein the second end of the second trailing arm (10R) is connected to the second yoke element (23R) such that the second trailing arm (10R) is pivotable about the second vertical axis (Z1R); and- the second end of the first trailing arm position control actuator (18L) is connected to the first yoke element (23L), and the second end of the second trailing arm position control actuator (18R) is connected to the second yoke element (23R).

7. The vehicle according to claim 6, wherein:- the first pivot mechanism (8L) comprises a first resilient element (24L) connected on its first end to the vehicle load-carrying structure (1), on its second end connected to first yoke element (23L) and capable of restraining the vertical movement of the first wheel (11 L);- the second pivot mechanism (8R) comprises a second resilient element (24R) connected on its first end to the vehicle load-carrying structure (1), on its second end connected to second yoke element (23R) and capable of restraining the vertical movement of the second wheel (11 R).

8. The vehicle according to claim 6, wherein:- the first pivot mechanism (8L) comprises a first resilient element (24L) connected on its first end to the vehicle load-carrying structure (1), on its second end connected to first steering knuckle (13L) and capable of restraining the vertical movement of the first wheel (11 L);- the second pivot mechanism (8R) comprises a second resilient element (24R) connected on its first end to the vehicle load-carrying structure (1), on its second end connected to second steering knuckle (13R) and capable of restraining the vertical movement of the second wheel (11 R).

9. The vehicle according to claim 1 , wherein:- a rotary element (28) is connected to the vehicle load carrying structure by a joint (29), allowing its rotation around a substantially horizontal axis (X1)- the first pivot mechanism (8L) comprises a first resilient element (25L) connected on its first end to the first end of a rotary element (28), on its second end connected to first trailing arm (10L) and capable of restraining the vertical movement of the first wheel (11 L);- the second pivot mechanism (8R) comprises a second resilient element (25R) connected on its first end to the second end of a rotary element (29), on its second end connected to second trailing arm (10R) and capable of restraining the vertical movement of the second wheel (11 R).

10. The vehicle according to any of the previous claims, wherein the resilient elements (25L, 25R) are spring elements.

11. The vehicle according to any of claims 1-9, wherein the resilient elements (25L, 25R) are push rods of a fixed length connected to flexible elements such as torsion bars.

12. The vehicle according to any of the previous claims, wherein the control unit (C) is configured to adjust the first lateral adjustment mechanism (7L) and the second lateral adjustment mechanism (7R) based on accelerometers measuring lateral forces acting on the vehicle.

13. The vehicle according to any of the previous claims, wherein the control unit (C) is configured to adjust the first lateral adjustment mechanism (7L) and the second lateral adjustment mechanism (7R) based on gyroscopes measuring lateral forces acting on the vehicle.

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