High-integration driving unit integrating active variable kingpin lateral offset function and kingpin steering function

Abstract

The invention discloses a high-integration traveling unit integrating an active variable kingpin transverse offset function and a kingpin steering function. The high-integration traveling unit comprises a wheel assembly, a steering system, a suspension system and an active variable offset system. The running unit integrates a driving system, a braking system, a rotating system and a suspending system, wherein the driving system and the braking system are both integrated on the wheel assembly; and the steering system and the suspension system respectively adopt an independent steering form of main pin steering and a double-bulb double-wishbone suspension form. In addition, the driving unit is additionally provided with the active variable offset system between the steering knuckle and the lower control arm of the suspension system, and the virtual kingpin inclination angle is changed by actively adjusting the distance between double ball heads of the lower control arm. The contradiction that after a steering system breaks down, the kingpin offset of a faulted wheel needs to be increased to conduct driving and braking longitudinal force steering fault-tolerant control, but the kingpin offset of a non-faulted wheel needs to be reduced to avoid the situation that the steering angle tracking performance of the wheel on the side is affected by synchronous and rapid changing wheel longitudinal force is avoided.

Description

Technical Field

[0001] The present invention relates to the field of intelligent by - wire chassis for electric vehicles, and particularly to a highly integrated driving unit integrating the functions of active variable kingpin lateral offset and kingpin steering. Background Art

[0002] With the rapid development of the automotive industry, four - wheel independent steering technology has become the focus of future by - wire chassis research and development due to its higher flexibility compared with traditional steering forms. However, due to the lack of mechanical connection between the left and right wheels and between the wheels and the steering wheel, the reliability of four - wheel independent steering technology has always been an important factor restricting its development. The differential error - tolerance technology makes use of the characteristics of distributed drive of future by - wire chassis. After the steering system fails, through the intervention of the drive system, it ensures that the wheel angle can still follow the target angle without instability. In this process, the kingpin offset of the suspension system plays a crucial role. It is the existence of the kingpin offset that makes the driving force generate a steering moment around the kingpin, thereby realizing the control of the wheel angle. If the vehicle kingpin offset is zero, the driving force will not be able to perform the corresponding differential error - tolerance control.

[0003] In actual control, for the faulty wheel using differential error - tolerance control, its driving force often changes frequently to ensure the desired steering angle. However, since the control frequencies of the vehicle's desired driving torque and desired yaw torque are significantly lower than the differential error - tolerance control frequency, this leads to rapid high - frequency changes in the driving force of the non - faulty wheels. Due to the existence of the lateral offset, the rapidly changing driving force will cause significant interference to the non - faulty wheels. Therefore, to solve the contradiction that the faulty wheels in differential error - tolerance control require kingpin offset, while the non - faulty wheels do not, a structure that can achieve active variable offset is urgently needed. Compared with the scheme of directly changing the wheelbase, to ensure the vehicle's operation, the process of active variable offset should avoid wheel side - slip and minimize the change of other wheel alignment parameters, especially the wheel camber angle. Summary of the Invention

[0004] To improve the safety and reliability of four - wheel independent steering vehicles and ensure the tracking performance of non - faulty wheels when the vehicle's steering system fails, the present invention proposes a highly integrated driving unit integrating the functions of active variable kingpin lateral offset and kingpin steering. It is characterized by including:

[0005] A wheel assembly (1000) for carrying the vehicle load and driving or braking the vehicle. The wheel assembly internally integrates a drive system and a braking system for vehicle longitudinal control. Among them, the drive system adopts the drive form of an outer - rotor hub motor, and the braking system adopts a by - wire braking form;

[0006] Steering system (2000), used to drive the wheels to generate a deflection movement around the kingpin axis. The steering system includes a steering motor assembly and a constant velocity joint, adopting an independent steering form of kingpin steering. The center of the constant velocity joint is the upper end point on the kingpin axis. The steering motor assembly includes a steering motor, a steering reducer, and a steering motor assembly housing;

[0007] Suspension system (3000), used to achieve buffering and vibration reduction of the wheels. The suspension system adopts a double-ball-joint double-wishbone suspension form, including a steering knuckle, a front lower control arm, a rear lower control arm, an upper control arm, and a shock absorber assembly. The steering motor assembly is installed on the steering knuckle. The steering knuckle is connected to the upper control arm through the constant velocity joint of the steering system. The intersection point of the extension lines of the front lower control arm and the rear lower control arm is the lower end point of the kingpin, which together with the upper end point on the kingpin axis determines the virtual kingpin axis. When the virtual kingpin is designed, it should have reasonable kingpin inclination and a non-zero kingpin offset;

[0008] Active kingpin offset system (4000), used to actively change the lateral offset of the kingpin axis. The active kingpin offset system includes an actuator assembly, a front swing arm, and a rear swing arm. The front and rear swing arms are installed between the steering knuckle of the suspension system and the front and rear lower control arms, and are respectively connected to the front and rear lower control arms through ball joints. The active kingpin offset system realizes the change of the double-ball-joint spacing of the lower control arm by controlling the movement of the front and rear swing arms, and then changes the angle between the front lower control arm and the rear lower control arm to realize the adjustment of the position of the lower end point of the kingpin, so as to realize the active change of the kingpin offset. And the actuator assembly has a self-locking function after adjustment to ensure driving safety.

[0009] Preferably, the wheel assembly (1000) is characterized by including:

[0010] Wheel hub (1020), which is integrally divided into a rim and a spoke. The rim is annular and used to install the tire (1010). Outer edges are provided on both sides to prevent the tire from falling off. The rim is composed of multiple spokes. A wheel axle through-hole is provided at the center of the spoke connection. The wheel axle through-hole should have a good machined surface that meets the requirements of fitting with the hub motor bearing. A plurality of drive motor threaded through-holes are provided around the wheel axle through-hole. The threaded through-holes are all counterbore holes and are fixedly connected to the outer rotor of the outer-rotor hub motor through bolts;

[0011] Wheel axle (1030), with threads tapped at the head, is limit-connected to the wheel hub through an end nut and a hub motor bearing. Splines and a shoulder are provided in the middle, and a flange is provided at the tail. The flange is provided with a plurality of threaded holes for installing the steering knuckle. The whole wheel axle should have a good machined surface that meets the requirements of fitting with the hub motor bearing;

[0012] The drive motor (1040) is an outer-rotor in-wheel motor. The stator is installed at the spline in the middle of the wheel shaft through splines. On the wheel-side end face of the outer rotor, there are multiple hub threaded holes, which are fixedly connected to the threaded through holes of the drive motor on the hub through screws, used to transmit the output torque of the drive motor to the hub and drive the vehicle to travel. On the body-side end face of the outer rotor of the drive motor, there are multiple brake disc threaded holes;

[0013] The braking system (1050) includes a brake disc and a brake caliper. The brake disc is installed on the brake disc threaded holes on the body-side end face of the outer rotor of the drive motor through screws and rotates together with the outer rotor of the drive motor and the hub. The brake caliper is fixed on two lugs of the steering knuckle; the braking system adopts a by-wire floating caliper form, and the brake caliper clamps on the outer edge of the brake disc with a proper braking gap left.

[0014] Preferably, the steering system (2000) is characterized by including:

[0015] A quasi-constant velocity universal joint (2010) is used to transmit the load between the steering knuckle and the upper control arm in the suspension system. The quasi-constant velocity universal joint is a three-ball pin type universal joint. The input end is successively provided with a shoulder, a thread and a spline, and the output end is successively provided with a shoulder, a spline and a thread. The input end is connected to the steering knuckle of the suspension system through a shoulder and a nut, and the output shaft is connected to the upper control arm of the suspension system through a shoulder, a spline and a nut;

[0016] The steering motor assembly (2020) is cylindrical as a whole. The steering motor assembly is connected to the steering knuckle through screws. The output end at the top of the steering motor assembly is connected to the spline of the input end of the quasi-constant velocity universal joint to transmit the steering torque.

[0017] Preferably, the steering motor assembly (2020) is characterized by including:

[0018] The steering motor assembly housing, the steering motor and the steering reducer;

[0019] Among them, the steering motor assembly housing is cylindrical as a whole, with bosses provided in the middle of the front and rear sides. There are threaded holes on the top of the bosses. Inside the steering motor assembly housing, there is a support frame for fixing the steering motor and the steering reducer; the steering motor is a permanent magnet synchronous motor, its stator is fixed on the support frame of the steering motor housing, and the rotor is connected to the input shaft of the steering reducer through a flat key; the output shaft and the input shaft of the steering reducer are on the same axis, used to amplify the output torque of the steering motor, and its output shaft is the output shaft of the steering motor assembly, with a spline groove provided at the top.

[0020] Preferably, the suspension system (3000) is characterized by including:

[0021] The knuckle (3010) is in the shape of an irregular plate as a whole. A weight-reducing hole is provided at the center, and countersunk holes for installing the wheel shaft are provided around it. The knuckle is connected to the flange of the wheel shaft through bolts and has an axial clearance from the brake disc. Both the weight-reducing hole and the through hole for installing the brake disc are located on the boss protruding towards the vehicle body side. At the top and bottom of the knuckle, "L"-shaped arms bent towards the vehicle body side are provided, namely the upper control arm and the active variable offset system arm respectively. A through hole is provided on the upper control arm for passing through the input end of the constant velocity universal joint of the steering system. Front and rear gear shaft through holes are provided on the active variable offset system arm, and these two through holes should have good machined surfaces to ensure the mating characteristics. At the outer edge of the front side of the knuckle, a pair of brake caliper lugs are provided, and through holes for installing the brake caliper are provided thereon, and a boss for ensuring a reasonable braking clearance of the brake caliper is provided on the wheel side. On the upper part of the vehicle body side of the knuckle, a pair of steering motor lugs are provided, and through holes for installing the steering motor assembly are provided thereon. At the lower part of the vehicle body side of the knuckle, three execution assembly bosses, namely the front, middle and rear bosses, are provided respectively, and threaded holes are provided thereon for installing the execution assembly. The front and rear execution assembly bosses are both arranged on the corresponding knuckle lugs.

[0022] The front lower control arm (3020) and the rear lower control arm (3030) are rod-shaped as a whole. Ball seats for installing ball joints are provided on the wheel sides of the front and rear lower control arms, and are connected to the corresponding swing arms through ball joints. Pin holes are provided on the vehicle body sides and are connected to the vehicle body or the subframe through pins and bushings. The bushings should ensure the normal movement of the front and rear lower control arms without interference during the active variable offset process. The pin holes of the two control arms should be coaxially arranged. The distance between the two ball seats should be less than the distance between the two pin holes. Lightweight grooves are provided on both sides of the front lower control arm and the rear lower control arm.

[0023] The upper control arm (3040) is in the shape of a "Y" as a whole and is composed of two intersecting arms. A universal joint spline groove is provided at the intersection of the arms and is spline-connected to the spline of the universal joint output shaft. A pair of shock absorber lugs are provided at the top, and through holes for installation are provided on the lugs. The design of the shock absorber lugs should ensure that there is no movement interference between the upper control arm and the shock absorber when the suspension system is working normally. Pin holes are provided at the ends of the two intersecting arms and are connected to the vehicle body or the subframe through pins and bushings. The pin holes of the two intersecting arms should be coaxially arranged.

[0024] The shock absorber assembly (3050) is used to mitigate road surface impacts and weaken the vibration amplitude. It includes a telescopic shock absorber and a coil spring, which are coaxially arranged. A shock absorber support rod is provided at the bottom of the shock absorber assembly. Lugs are provided at the ends of the support rod and at the top of the shock absorber, and the lugs are respectively connected to the shock absorber lugs of the upper control arm and the vehicle body through pins.

[0025] Preferably, the active variable offset system (4000) is characterized by comprising:

[0026] An execution assembly (4010) for driving the front and rear swing arms to move to achieve the active variable offset function of the traveling unit. The whole is an irregular cube, including a first housing, a second housing, an execution motor, a worm shaft, a worm gear, an active gear shaft, and a driven gear shaft. It is connected to the front, middle, and rear execution assembly bosses on the steering knuckle through screws passing through the through holes provided on the first housing and the second housing; the bottom of the execution assembly is provided with a front output shaft and a rear output shaft, both of which are sequentially provided with shoulders, splines, and threads. The front and rear output shafts respectively pass through the front and rear gear shaft through holes provided on the active variable offset system arms of the steering knuckle and are axially fixed through shoulders.

[0027] A front swing arm (4020) and a rear swing arm (4030) for transmitting the torque output by the execution assembly to the front and rear lower control arm ball seat positions; the front swing arm and the rear swing arm are both rod-shaped as a whole, and are respectively provided with spline grooves at the top on the wheel side, and are connected to the front and rear output shafts of the execution through splines and nuts. Threaded holes are respectively provided at the bottom on the vehicle body side, and are respectively connected to the front and rear lower control arm ball seats through ball joints.

[0028] Preferably, the execution assembly (4010) is characterized by comprising:

[0029] A first housing (4011) and a second housing (4012), both of which are irregular cubes, and are respectively provided with empty grooves on the vehicle body side and the wheel side that can ensure the normal meshing operation of the execution motor, the worm shaft, the worm gear, the active gear shaft, and the driven gear shaft, namely an execution motor groove, a worm shaft groove, a worm gear groove, an active gear shaft groove, and a driven gear shaft groove. Among them, an execution motor through hole is provided at the rear of the execution motor groove. The tops of the active gear shaft groove, the driven gear shaft groove, and the front of the worm shaft groove should all have good machining surfaces to ensure the shaft bush matching characteristics. The first housing and the second housing are both provided with three front, middle, and rear installation through holes to be connected to the steering knuckle through screws. The three installation through holes are all provided with bosses on the vehicle body side of the second housing. The front installation through hole is installed on the corresponding steering knuckle lug, and the rear installation through hole and the execution motor through hole are the same through hole.

[0030] An execution motor (4013), which is a brushless DC motor. The stator is provided with a lug at the tail, and an installation through hole is provided thereon to be fixedly connected to the rear installation through hole of the first housing and the rear installation through hole of the second housing through screws. The rotor is provided with a flat key groove.

[0031] Worm shaft (4014), with a worm in the middle, a flat keyway at the tail for connection with the flat keyway of the actuator motor, a head with a good machined surface to ensure mating characteristics, and mating with the worm shaft grooves of the first housing and the second housing through a bearing bush;

[0032] Worm gear (4015), meshing with the worm on the worm shaft, and a spline groove at the center;

[0033] Drive gear shaft (4016), with a spur gear in the middle, shoulders provided both above and below the spur gear, and both should have a good machined surface to ensure mating characteristics. The top mates with the worm shaft grooves of the first housing and the second housing through a bearing bush, the bottom mates with the through hole of the front steering knuckle gear shaft, and splines and threads are provided both at the top and the bottom. The top of the drive gear shaft is fixedly connected to the worm gear through a spline and a nut, and the bottom extends out of the first housing and the second housing to serve as the front output shaft, and is fixedly connected to the spline groove of the front swing arm through a spline and a nut;

[0034] Driven gear shaft (4017), with a spur gear at the upper middle part meshing with the spur gear of the drive gear shaft, shoulders provided both above and below the spur gear, and both should have a good mating surface to ensure mating characteristics. The top mates with the worm shaft grooves of the first housing and the second housing through a bearing bush, the bottom mates with the through hole of the rear steering knuckle gear shaft, and a spline and a thread are provided at the bottom, extending out of the first housing and the second housing to serve as the rear output shaft, and is fixedly connected to the spline groove of the rear swing arm through a spline and a nut.

[0035] Preferably, the active variable offset system (4000) is characterized in that:

[0036] The active variable offset system can ensure that the lateral offset of the kingpin axis is reduced to zero and there is no movement interference during the working process;

[0037] The designed lengths and initial angles of the front swing arm and the rear swing arm should ensure that during the active variable offset process, while the included angle of the front and rear lower control arms changes to a certain extent, the wheel camber angle remains unchanged.

[0038] Preferably, the highly integrated driving unit can implement an active variable offset control method for a steering failure process, characterized in that;

[0039] S0: Start;

[0040] S1: The control unit detects the fault signal of the steering system;

[0041] S2: The control unit determines whether there is a fault in the steering system. If there is a fault, execute S3; if there is no fault, return to S1;

[0042] S3: The control unit deactivates the steering system of the faulty wheel;

[0043] S4: The control unit activates the differential fault tolerance control of the faulty wheel, that is, the drive-brake longitudinal force steering fault tolerance control;

[0044] S5: The control unit activates the active variable offset system of the non-faulty wheels, and actively reduces the lateral offset of the non-faulty wheels;

[0045] S6: End;

[0046] Wherein the differential fault tolerance control is to generate a steering torque that forces the wheel to rotate around the kingpin axis through the longitudinal force control of the wheel, thereby realizing the tracking control of the target wheel angle and realizing the differential steering function; the steering torque is proportional to the product of the wheel longitudinal force and the kingpin offset.

[0047] Preferably, the high-integration driving unit can implement an active variable offset control method for a non-steering fault process, characterized in that;

[0048] When there is no steering fault, according to the current vehicle handling and stability control requirements, the active variable offset systems of the left and right driving units simultaneously increase or decrease the kingpin lateral offset to improve the steering flexibility under large-angle conditions during low-speed driving and the straight-line driving stability during drive-brake driving at high speed.

[0049] Advantages of the present invention:

[0050] 1. The present invention proposes a high-integration driving unit integrating the functions of active variable kingpin lateral offset and kingpin steering. Adopting four-wheel independent steering technology, it can effectively improve the vehicle freedom, expand the vehicle control boundary, and realize special steering technologies that traditional vehicles cannot achieve.

[0051] 2. The present invention proposes a high-integration driving unit integrating the functions of active variable kingpin lateral offset and kingpin steering. It can realize the active change of the vehicle lateral offset on the premise that the wheels do not have side slip and other wheel alignment parameters, especially the wheel camber angle, do not change significantly. It effectively solves the contradiction that in the steering system fault, the faulty wheel needs the kingpin offset for differential fault tolerance control, while the non-faulty wheels do not need the kingpin offset to reduce the influence of the rapidly changing longitudinal force on the wheel angle tracking performance.

[0052] 3. The present invention proposes a high-integration driving unit integrating the functions of active variable kingpin lateral offset and kingpin steering. It uses a universal joint to replace the spline connection between the steering motor and the steering knuckle in the traditional kingpin steering structure, thereby ensuring that the vehicle can passively adapt to the inevitable kingpin inclination change during the active variable offset process. Description of the Drawings

[0053] Figure 1 The assembly schematic diagram of a highly integrated driving unit that integrates the functions of actively varying the kingpin lateral offset and kingpin steering according to the present invention.

[0054] Figure 2 The sectional view of a highly integrated driving unit that integrates the functions of actively varying the kingpin lateral offset and kingpin steering according to the present invention.

[0055] Figure 3 The exploded view of parts of a highly integrated driving unit that integrates the functions of actively varying the kingpin lateral offset and kingpin steering according to the present invention.

[0056] Figure 4 The schematic diagram of the maximum offset of a highly integrated driving unit that integrates the functions of actively varying the kingpin lateral offset and kingpin steering according to the present invention.

[0057] Figure 5 The schematic diagram of the minimum offset of a highly integrated driving unit that integrates the functions of actively varying the kingpin lateral offset and kingpin steering according to the present invention. Specific implementation solutions

[0058] The following further elaborates on the present invention in conjunction with the accompanying drawings, so that those skilled in the art can implement it with reference to the text of the specification.

[0059] The present invention provides a highly integrated driving unit that integrates the functions of actively varying the kingpin lateral offset and kingpin steering, which is characterized by including: a wheel assembly (1000), a steering system (2000), a suspension system (3000), and an active offset system (4000), as Figure 1 shown.

[0060] Among them, the wheel assembly (1000) includes a tire (1010), a wheel hub (1020), a wheel axle (1030), a drive motor (1040), and a braking system (1050), and is used for carrying vehicle loads and longitudinal control of the vehicle. Among them, the drive system adopts the drive form of an outer-rotor in-wheel motor, and the braking system adopts the form of electronic brake control;

[0061] Among them, the wheel hub (1020) is integrally divided into a rim and spokes. The rim is annular and is used to mount the tire (1010). Outer edges are provided on both sides to prevent the tire from falling off. The rim is composed of multiple spokes. A wheel axle through-hole is provided at the center of the connection of the spokes. In terms of the shape design of the spokes, it should be ensured that there is no interference with the brake caliper during the normal rotation of the vehicle. At the same time, good aerodynamic characteristics of the spokes should be ensured. The wheel axle through-hole should have a good machined surface that meets the requirements of mating with the hub motor bearing. A plurality of drive motor threaded through-holes are provided around the wheel axle through-hole. The threaded through-holes are all countersunk holes. Similarly, to ensure good aerodynamic characteristics, the tire can be either a traditional pneumatic tire, a non-pneumatic tire or other new types of tires;

[0062] Among them, for the wheel axle (1030), its head is tapped with threads and is connected to the hub in a limited way through an end nut and a hub motor bearing, and is connected to the wheel axle through-hole of the hub in a limited way through an end nut and a first hub motor bearing. The end nut is used to determine the axial displacement of the first hub motor bearing. A spline and a shoulder are provided in the middle of the wheel axle. The shoulder ensures that the second hub motor bearing has no axial displacement. A flange is provided at the tail. The flange is provided with a plurality of threaded holes for installing the steering knuckle. The whole wheel axle should have a good machined surface that meets the requirements of mating with the hub motor bearing;

[0063] Among them, for the drive motor (1040), it is an outer rotor motor. The motor should ensure good shell stiffness, be used to be fixedly connected to the outer rotor and help transmit its torque. The inner stator should be hollow and have an internal spline, and is installed at the spline of the wheel axle through the internal spline to limit the tangential displacement of the stator. The hub and the brake disc limit their axial displacement through contact. Hub threaded holes are provided on the outer side of the outer rotor motor shell and are fixedly connected to the drive motor threaded holes of the hub through bolts, so as to transmit the driving torque to the hub and the tire. Brake disc threaded holes are provided on the inner side of the outer rotor motor shell. The selected outer rotor drive motor should have characteristics such as high specific power, strong anti-electromagnetic interference ability, not sensitive to temperature changes, able to resist wheel vibration, simple control and low cost;

[0064] Among them, the braking system (105) includes a brake disc and a brake caliper. A flange is provided inside the brake disc. The outer side of the flange is installed on the brake disc threaded holes of the drive motor shell through bolts, is fixedly connected to the outer rotor of the drive motor, and rotates together with the hub. The inside of the brake disc flange is assembled to the wheel axle through a second hub motor bearing and transmits the axial load between the wheel axle and the drive motor. The brake caliper should be selected as electro-mechanical or electro-hydraulic brake actuation, and is clamped at the outer edge of the brake disc with a proper braking gap. The braking form should be a floating caliper type. At the same time, brake caliper lugs are provided at the outer edge of the brake caliper for installation;

[0065] Among them, the steering system (2000) is used to drive the wheels to generate a rotational movement around the kingpin axis. The steering system includes a steering motor assembly (2020) and a constant velocity joint (2010), adopting an independent steering form of kingpin steering. The center of the constant velocity joint is the upper endpoint on the kingpin axis. The steering motor assembly includes a steering motor, a steering reducer, and a steering motor assembly housing.

[0066] Among them, the constant velocity joint (2010) is used to transmit the load between the steering knuckle and the upper control arm in the suspension system. The constant velocity joint is a three-ball pin type universal joint. The input end is sequentially provided with a shoulder, a thread, and a spline, and the output end is sequentially provided with a shoulder, a spline, and a thread. The input end is connected to the steering knuckle of the suspension system through a shoulder and a nut, and the output shaft is connected to the upper control arm of the suspension system through a shoulder, a spline, and a nut. The center of the universal joint is the upper endpoint of the kingpin axis; in some examples, the three-ball pin type constant velocity joint can also be replaced by a double-offset type universal joint or a cross-slot type universal joint. The constant velocity joint replaces the position of the upper ball joint in the traditional double-wishbone suspension, that is, it ensures that the steering motor can still provide a steering torque during the wheel jounce process, and also ensures passive adaptation to different kingpin angles during the active variable offset process.

[0067] Among them, the steering motor assembly (2020) includes a steering motor assembly housing, a steering motor, and a steering reducer, and is cylindrical as a whole. The steering motor assembly is connected to the steering knuckle through screws. The top output end of the steering motor assembly is provided with a spline groove to connect with the input end of the constant velocity joint to transmit the steering torque. The steering motor assembly should have a certain sealing function to prevent external dust and rainwater from seeping in and interfering with the operation of the steering motor.

[0068] The housing of the steering motor assembly is cylindrical as a whole, with bosses provided in the middle of the front and rear sides. Threaded holes are provided at the tops of the bosses. A support frame for fixing the steering motor and the steering reducer is provided inside the housing of the steering motor assembly; the steering motor is a permanent magnet synchronous motor. The selection of the steering motor should ensure the characteristics of high torque output, fast response, high efficiency, low noise, low vibration, and high reliability. Its stator is fixed on the support frame of the housing of the steering motor, and the rotor is connected to the input shaft of the steering reducer through a flat key. The connection between the steering motor and the support frame should, while ensuring the support strength, also ensure that the steering motor still has sufficient heat dissipation capacity to avoid functional failure caused by overheating of the steering motor. At the same time, since the steering motor assembly is directly installed on the steering knuckle without the buffering of the suspension system, the support frame should also have a certain buffering and vibration damping effect to reduce the impact on the steering motor during the wheel bounce; the output shaft and the input shaft of the steering reducer are on the same axis and are used to amplify the torque of the steering reducer. Its output shaft is the output shaft of the steering motor assembly, and a spline groove is provided at the top. The steering reducer can adopt a planetary gear reducer, a harmonic reducer, a cycloid pinwheel reducer, or other coaxial reducers.

[0069] The suspension system (3000) is used to achieve the buffering and vibration damping of the wheels. The suspension system adopts a double-ball-head double-wishbone form and includes a steering knuckle (3010), a front lower control arm (3020), a rear lower control arm (3030), an upper control arm (3040), and a shock absorber assembly (3050). The steering motor assembly is installed on the steering knuckle. The steering knuckle is connected to the upper control arm through the constant velocity universal joint of the steering system. The intersection of the extension lines of the front lower control arm and the rear lower control arm is the lower endpoint of the kingpin, which together with the upper endpoint of the kingpin axis determines the virtual kingpin axis;

[0070] Among them, the knuckle (3010) is an irregular plate as a whole, with a weight-reducing hole at the center, and countersunk holes for installing the wheel axle are provided around it, which are connected to the flange of the wheel axle through bolts and have an axial clearance from the brake disc. The weight-reducing hole and the through hole for installing the brake disc are both located on the boss protruding towards the vehicle body side. "L"-shaped arms bent towards the vehicle body side are provided at the top and bottom of the knuckle, which are the upper control arm and the active variable offset system arm respectively. A through hole is provided on the upper control arm for passing the input end of the quasi-constant velocity universal joint of the steering system. Front and rear gear axle through holes are provided on the active variable offset system arm. The through holes should have good machined surfaces to ensure the mating characteristics. A pair of brake caliper lugs are provided at the outer edge of the front side of the knuckle, and through holes for installing the brake caliper are provided thereon, and a boss for ensuring a reasonable braking clearance of the brake caliper is provided on the wheel side. A pair of steering motor lugs are provided at the upper part of the knuckle on the vehicle body side, and through holes for installing the steering motor assembly are provided thereon. At the lower part of the knuckle on the vehicle body side, three execution assembly bosses, namely a front one, a middle one and a rear one, are provided respectively, and threaded holes are provided thereon for installing the execution assembly. The front and rear execution assembly bosses are both arranged on the corresponding lugs. The knuckle should be provided with fillets or chamfers in the stress concentration areas. The knuckle is a key component in the process of transmitting loads for the wheel and should be made of a metal material with good load-bearing capacity;

[0071] Among them, the front lower control arm (3020) and the rear lower control arm (3030) are rod-shaped as a whole. The intersection point of the connection line between the two determines the lower end point of the kingpin axis. At the beginning of the virtual kingpin design, it should have reasonable kingpin inclination and a non-zero kingpin offset. Ball head seats for installing ball joints are provided on the wheel sides of the front and rear lower control arms, and are connected to the corresponding swing arms through ball joints. Pin holes are provided on the vehicle body sides and are connected to the vehicle body or the subframe through pins and bushings. The bushings should be able to ensure the normal movement of the front and rear lower control arms without interference during the active variable offset process. The pin holes should be coaxially arranged. The distance between the two ball head seats should be less than the distance between the two pin holes. Lightweight grooves are provided on both sides of the front lower control arm and the rear lower control arm. The front lower control arm and the rear lower control arm are key components in the process of transmitting loads for the wheel and should be made of a metal material with good load-bearing capacity;

[0072] Among them, the upper control arm (3040) is "Y"-shaped as a whole and consists of two intersecting arms. A universal joint spline groove is provided at the intersection of the arms and is fixedly connected to the output shaft of the universal joint. A pair of shock absorber lugs are provided at the top, and through holes for installation are provided on the lugs. The design of the shock absorber lugs should ensure that there is no movement interference between the upper control arm and the shock absorber when the suspension system is working properly. Pin holes are provided at the ends of the intersecting arms and are connected to the vehicle body or the subframe through pins and bushings. The upper control arm is a key component in the process of transmitting loads for the wheel and should be made of a metal material with good load-bearing capacity;

[0073] The shock absorber assembly (3050) is used to mitigate road surface impacts and weaken the vibration amplitude. It includes a telescopic shock absorber and a coil spring, which are arranged coaxially. A shock absorber support rod is provided at the bottom of the shock absorber assembly. Lugs are provided at the ends of the support rod and the top of the shock absorber, and are respectively connected to the shock absorber lug of the upper control arm and the vehicle body through a pin shaft. In some instances, the telescopic shock absorber can be replaced with a CDC shock absorber or an MRC shock absorber; in some instances, the coil spring can be replaced with an air spring or an oil-gas spring; in some instances, an active actuator can also be added outside the shock absorber assembly.

[0074] The active variable offset system (4000) is used to actively change the lateral offset of the kingpin axis. It includes an actuator assembly (4010), a front swing arm (4020), and a rear swing arm (4030). The front and rear swing arms are installed between the steering knuckle and the front and rear lower control arms of the suspension system, and are connected to the front and rear lower control arms through ball joints. The active variable offset system realizes the change of the distance between the two ball joints of the lower control arm by controlling the movement of the swing arms, thereby changing the position of the lower end point of the kingpin and realizing the active change of the kingpin offset. And the actuator assembly has a self-locking function.

[0075] The actuator assembly (4010) is used to drive the swing arms to move to realize the active variable offset function of the driving unit. It is an irregular cube as a whole, and includes a first housing (4011), a second housing (4012), an actuator motor (4013), a worm shaft (4014), a worm gear (4015), an active gear shaft (4016), and a driven gear shaft (4017). It is connected to the front, middle, and rear actuator assembly bosses on the steering knuckle through screws through the through holes provided on the first housing and the second housing. The bottom of the actuator assembly is provided with a front output shaft and a rear output shaft, which are sequentially provided with shoulders, splines, and threads. The front and rear output shafts respectively pass through the front and rear gear shaft through holes on the active variable offset system support arms of the steering knuckle and are axially fixed through shoulders;

[0076] Among them, the first housing (4011) and the second housing (4012) are both irregular cubes, and are respectively provided with empty slots on the vehicle body side and the wheel side to ensure the normal meshing operation of the actuator motor, worm shaft, worm gear, driving gear shaft and driven gear shaft, namely the actuator motor slot, worm shaft slot, worm gear slot, driving gear shaft slot and driven gear shaft slot. The rear part of the actuator motor slot is provided with an actuator motor through hole. The tops of the driving gear shaft slot, the driven gear shaft slot and the front part of the worm shaft slot should all have good machined surfaces to ensure the bearing bush matching characteristics. The first housing and the second housing are both provided with three front, middle and rear mounting through holes to be connected to the steering knuckle by screws. The three mounting through holes are all provided with bosses on the vehicle body side of the second housing. The front mounting through hole is mounted on the corresponding lug. The rear mounting through hole and the actuator motor through hole are the same through hole. Among them, the first housing and the second housing should be provided with rounded corners or chamfers in the stress concentration areas. At the same time, to ensure normal lightweighting, lightweighting slots should be started at appropriate positions. The contact surfaces of the first housing and the second housing should have good machining characteristics, and good lubrication effects should be ensured in the bearing bush installation areas.

[0077] Among them, the actuator motor (4013) is a brushless DC motor. The stator tail is provided with a lug, and an installation through hole is provided thereon to be fixedly connected to the first housing and the second housing by screws. The rotor is provided with a flat keyway. The layout of the actuator motor should ensure its good heat dissipation effect;

[0078] Among them, the worm shaft (4014) is provided with a worm in the middle, and a flat keyway at the tail is connected to the flat keyway of the actuator motor. The head has a good machined surface to ensure the matching characteristics, and is matched with the worm shaft slots of the first housing and the second housing through bearing bushes;

[0079] Among them, the worm gear (4015) meshes with the worm on the worm shaft, and a spline groove is provided at the center;

[0080] Among them, the driving gear shaft (4016) is provided with a spur gear in the middle. Both the upper and lower parts of the spur gear are provided with shoulders, and both should have good machined surfaces to ensure the matching characteristics. The top is matched with the worm shaft slots of the first housing and the second housing through bearing bushes. The bottom is matched with the through hole of the front gear shaft of the steering knuckle. Both the top and the bottom are additionally provided with splines and threads. Among them, the top of the driving gear shaft is fixedly connected to the worm gear through splines and nuts. The bottom extends out of the first housing and the second housing and serves as the front output shaft, and is fixedly connected to the spline groove of the front swing arm through splines and nuts;

[0081] Among them, for the driven gear shaft (4017), a spur gear is provided in the upper middle part and meshes with the spur gear on the driving gear shaft. Shoulder shafts are provided both above and below the spur gear, and both should have good mating surfaces to ensure mating characteristics. The top is fitted with a journal bearing in the worm shaft grooves of the first housing and the second housing, and the bottom is fitted with the through hole of the front knuckle gear shaft. Additionally, a spline and a thread are provided at the bottom, extending out of the first housing and the second housing to serve as the rear output shaft, and are fixedly connected to the spline groove of the rear swing arm through a spline and a nut.

[0082] Among them, the front swing arm (4020) and the rear swing arm (4030) are used to transmit the torque output by the actuator assembly to the ball joint seats of the front and rear lower control arms. They are overall rod-shaped. A spline groove is provided at the top on the wheel side and is connected to the front and rear output shafts of the actuator through a spline and a nut. A threaded hole is provided at the bottom on the vehicle body side and is connected to the ball joint seats of the front and rear lower control arms through a ball hinge.

[0083] The active variable offset system can ensure that the lateral offset of the kingpin axis is reduced to zero and there is no movement interference during the working process.

[0084] The designed lengths and initial angles of the front swing arm and the rear swing arm should ensure that during the active variable offset process, the camber angle of the wheel and the change angles of the front and rear lower control arms are minimized.

[0085] Among them, for a highly integrated driving unit integrating the functions of active variable kingpin lateral offset and kingpin steering, an active variable offset control method for the steering failure process is proposed, characterized in that;

[0086] S0: Start;

[0087] S1: The control unit detects the fault signal of the steering system;

[0088] S2: The control unit determines whether there is a fault in the steering system. If there is a fault, execute S3; if there is no fault, execute S1;

[0089] S3: The control unit deactivates the steering system of the faulty wheel;

[0090] S4: The control unit enables the differential fault tolerance control of the faulty wheel;

[0091] S5: The control unit enables the active variable offset system of the non-faulty wheels and actively reduces the lateral offset of the non-faulty wheels;

[0092] S6: End.

[0093] The differential error tolerance control generates a steering torque about the kingpin axis through the longitudinal force control of the wheel, thereby achieving the tracking control of the target wheel angle. The steering torque is proportional to the wheel longitudinal force and the kingpin offset.

[0094] A highly integrated driving unit integrating the functions of actively changing the kingpin lateral offset and the kingpin steering function proposes an active offset control method for the non-steering fault process, characterized in that;

[0095] When there is no steering fault, according to the current vehicle handling and stability control requirements, the active offset systems of the left and right driving units increase or decrease the kingpin lateral offset simultaneously to improve the steering flexibility under large-angle conditions during low-speed driving and the straight-line driving stability during driving with acceleration and braking at high speed.

[0096] The working principles of each system are as follows:

[0097] Drive system: After receiving the drive signal issued by the driver or the control unit, the outer rotor motor outputs a driving torque through the outer rotor. This torque is first transmitted to the drive motor housing fixed to the outer rotor, then transmitted to the wheel hub through the hub threaded holes on the drive motor housing, and finally the wheel hub transmits the driving torque to the ground through the tire, thereby driving the vehicle to move forward.

[0098] Braking system: After receiving the drive signal issued by the driver or the control unit, the braking system generates a braking force to push the brake caliper to clamp the brake disc, forcing the brake disc to generate a brake torque. The brake disc transmits the brake torque to the drive motor housing through the drive motor threaded holes in the middle. The drive motor housing transmits the brake torque to the ground through the wheel hub and tire fixed to it to generate a braking torque, thereby forcing the vehicle to brake.

[0099] Suspension system: When the wheel is subjected to a vertical load, due to the presence of the upper and lower control arms, the shock absorber assembly generates relative movement, thereby generating damping force and elastic force. This resistance will be transmitted to the upper control arm through the shock absorber support rod, thereby restricting the further swing of the upper control arm. The upper control arm transmits the resistance to the steering knuckle through the quasi-constant velocity universal joint. After receiving the resistance, the steering knuckle transmits the damping to the wheel axle. The wheel axle transmits the resistance to the wheel hub and the brake disc respectively through the first and second hub motor bearings on it. Among them, the brake disc transmits the resistance to the wheel hub through the same transmission path as in the braking process. The wheel hub transmits the resistance to the tire, thereby restricting the vertical movement of the wheel, achieving the function of buffering impact and weakening vibration. Similarly, if an actuator is installed in the suspension system, the actuator driving force can be transmitted to the wheel through a similar transmission route to generate vertical movement.

[0100] Active Variable Offset System: After receiving the variable offset command from the control unit, the actuating motor generates an actuating motion, which is transmitted to the worm shaft through the output shaft flat key, and then the actuating motion is transmitted to the driving gear shaft through the spline of the worm gear meshed with the worm. At the same time, the driven gear shaft generates the same actuating motion as the driving gear shaft through the meshed spur gear, and then the motion is transmitted to the front and rear swing arms through the spline, so as to convert the actuating motion into an increase in the distance between the ball pins of the front and rear lower control arms. Since the connection between the front and rear lower control arms and the vehicle body or subframe is through elastic bushings, they can receive the slight rotation of the front and rear lower control arms. At the same time, due to the change in the relative positions of the front and rear lower control arms, the intersection point of their extension lines moves towards the wheel side, but the upper endpoint of the kingpin remains unchanged, thus increasing the kingpin inclination angle and reducing the kingpin offset to zero. During this process, except for the obvious changes in the kingpin inclination angle and kingpin offset, there are no obvious changes in the wheel camber angle, wheel toe angle and kingpin caster angle, as shown in Figure 4 , 5 . At the same time, due to the self-locking characteristic of the worm and worm gear pair, no additional energy is consumed to maintain the angles of the front and rear swing arms during the non-variable offset process, which not only ensures the reliability of the active variable offset function but also reduces the vehicle energy consumption.

[0101] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and the examples shown and described here.

Claims

1. A highly integrated driving unit integrating active variable kingpin lateral offset function and kingpin steering function, characterized in that: include: A wheel assembly (1000) is used to carry a vehicle load and drive or brake a moving vehicle, wherein a drive system and a brake system for longitudinal control of the vehicle are integrated inside the wheel assembly, wherein the drive system adopts an outer rotor hub motor drive mode, and the brake system adopts a wire control brake mode; A steering system (2000) for driving a wheel to generate a deflection motion around a kingpin axis, the steering system comprising a steering motor assembly and a quasi-constant velocity universal joint, adopting an independent steering form of kingpin steering, the center of the quasi-constant velocity universal joint being the upper end point of the kingpin axis, the steering motor assembly comprising a steering motor, a steering reducer and a steering motor assembly housing; A suspension system (3000) is used to achieve wheel buffering and vibration reduction. The suspension system adopts a double ball head type double wishbone suspension form, including a steering knuckle, a front lower control arm, a rear lower control arm, an upper control arm and a shock absorber assembly. The steering knuckle is mounted with the steering motor assembly. The steering knuckle and the upper control arm are connected via a quasi-constant velocity universal joint of the steering system. The intersection of the extended lines of the front lower control arm and the rear lower control arm is the lower end point of the kingpin, which together with the upper end point of the kingpin axis defines a virtual kingpin axis. The virtual kingpin should have a reasonable kingpin inclination and a non-zero kingpin offset when it is initially designed. An active variable offset system (4000) is used to actively change the lateral offset of the kingpin axis. The active variable offset system includes an actuator assembly, a front swing arm and a rear swing arm. The front and rear swing arms are installed between the steering knuckle of the suspension system and the front and rear lower control arms, and are connected to the front and rear lower control arms through ball joints respectively. The active variable offset system changes the distance between the double ball joints of the lower control arms by controlling the movement of the front and rear swing arms, and then changes the angle between the front lower control arm and the rear lower control arm to adjust the position of the kingpin lower end point, thereby achieving active change of the kingpin offset. The actuator assembly has a self-locking function after adjustment to ensure driving safety.

2. A highly integrated driving unit integrating active variable kingpin lateral offset function and kingpin steering function according to claim 1, characterized in that: The wheel assembly (1000) is characterized by comprising: The wheel hub (1020) is divided into a rim and a spoke as a whole. The rim is annular and used for mounting a tire (1010). Outer edges are provided on both sides to prevent the tire from falling off. The rim is composed of a plurality of spokes. A wheel axle through hole is provided at the center of the spoke connection. The wheel axle through hole should have a good processing surface that meets the requirements for matching with the wheel hub motor bearing. A plurality of drive motor threaded through holes are provided around the wheel axle through hole. The threaded through holes are all countersunk holes and are fixedly connected to the outer rotor of the outer rotor wheel hub motor by bolts. The wheel shaft (1030) has a threaded head, is limitedly connected to the wheel hub through an end nut and a wheel hub motor bearing, is provided with a spline and a shaft shoulder in the middle, and is provided with a flange at the rear. The flange is provided with a plurality of threaded holes for installing a steering knuckle. The wheel shaft as a whole should have a good processing surface that meets the matching requirements with the wheel hub motor bearing; The drive motor (1040) is an outer rotor hub motor, the stator is installed at the spline in the middle of the wheel shaft through a spline, the wheel side end face of the outer rotor is provided with a plurality of wheel hub threaded holes, and is fixedly connected to the drive motor threaded through holes on the wheel hub through screws, so as to transmit the output torque of the drive motor to the wheel hub to drive the vehicle to travel, and the vehicle body side end face of the drive motor outer rotor is provided with a plurality of brake disc threaded holes; The brake system (1050) comprises a brake disc and a brake caliper, wherein the brake disc is mounted on a brake disc threaded hole on the vehicle body side end face of the drive motor outer rotor by means of screws and rotates together with the drive motor outer rotor and the wheel hub, and the brake caliper is fixed on two lugs at the steering knuckle; the brake system adopts a wire-controlled floating caliper form, and the brake caliper is clamped at the outer edge of the brake disc and leaves a suitable braking gap.

3. The highly integrated driving unit with active variable kingpin lateral offset function and kingpin steering function according to claim 1, characterized in that: The steering system (2000) is characterized by comprising: A quasi-constant velocity universal joint (2010), used for transmitting the load between the steering knuckle and the upper control arm in the suspension system, the quasi-constant velocity universal joint is a tripod-type universal joint, the input end is provided with a shaft shoulder, a thread and a spline in sequence, the output end is provided with a shaft shoulder, a spline and a thread in sequence, the input end is connected to the steering knuckle of the suspension system through a shaft shoulder and a nut, and the output shaft is connected to the upper control arm of the suspension system through a shaft shoulder, a spline and a nut; The steering motor assembly (2020) is cylindrical in shape as a whole. The steering motor assembly is connected to the steering knuckle via screws. The top output end of the steering motor assembly is spline-connected to the input end of the quasi-constant velocity universal joint to transmit steering torque.

4. The steering system (2000) according to claim 3, characterized in that: The steering motor assembly (2020) is characterized by comprising: Steering motor assembly housing, steering motor and steering reducer; The steering motor assembly housing is cylindrical as a whole, with bosses provided in the middle of the front and rear sides, and threaded holes provided on the tops of the bosses. A support frame for fixing the steering motor and the steering reducer is provided inside the steering motor assembly housing; the steering motor is a permanent magnet synchronous motor, whose stator is fixed on the support frame of the steering motor housing, and the rotor is connected to the steering reducer input shaft through a flat key; the steering reducer output shaft is located on the same axis as the input shaft, and is used to amplify the output torque of the steering motor, and its output shaft is the output shaft of the steering motor assembly, and a spline groove is provided on the top.

5. The highly integrated driving unit integrating active variable kingpin lateral offset function and kingpin steering function according to claim 1, characterized in that: The suspension system (3000) is characterized by comprising: The steering knuckle (3010) is in an irregular plate shape as a whole, with a weight-reducing hole at the center, and wheel axle mounting countersunk holes are arranged around it, which are connected to the wheel axle flange by bolts, and an axial gap is left with the brake disc, the weight-reducing hole and the brake disc mounting through hole are both located on a boss protruding toward the vehicle body side, and the top and bottom of the steering knuckle are both provided with "L"-shaped support arms bent toward the vehicle body side, which are an upper control arm support arm and an active variable offset system support arm, respectively, the upper control arm support arm is provided with a through hole for passing through the quasi-constant velocity universal joint input end of the steering system, and the active variable offset system support arm is provided with a front, The rear gear shaft through hole, the two through holes should have a good processing surface to ensure the matching characteristics; a pair of brake caliper lugs are provided at the outer edge of the front side of the steering knuckle, on which a through hole for installing the brake caliper is provided, and a boss is provided on the wheel side to ensure a reasonable braking clearance of the brake caliper; a pair of steering motor lugs are provided on the upper part of the steering knuckle body side, on which a through hole for installing the steering motor assembly is provided; the lower part of the steering knuckle body side is respectively provided with front, middle and rear three execution assembly bosses, all of which are provided with threaded holes for installing the execution assembly, and the front and rear execution assembly bosses are both arranged on the corresponding steering knuckle lugs; The front lower control arm (3020) and the rear lower control arm (3030) are rod-shaped as a whole. The wheel side of the front and rear lower control arms are provided with ball head seats for installing ball joints, which are connected to the corresponding swing arms through the ball joints. The vehicle body side is provided with pin shaft holes connected to the vehicle body or subframe through pin shafts and bushings. The bushings should be able to ensure that the normal movement of the front and rear lower control arms can be ensured without interference during the process of actively changing the offset distance. The pin shaft holes of the two control arms should be coaxially arranged, and the distance between the two ball head seats should be less than the distance between the two pin shaft holes. Lightweight grooves are provided on both sides of the front lower control arm and the rear lower control arm; The upper control arm (3040) is in a "Y" shape as a whole and is composed of two crossed arms. A universal joint spline groove is provided at the intersection of the arms and is spline-connected with the universal joint output shaft. A pair of shock absorber lugs are provided on the top. The lugs are provided with mounting through holes. The design of the shock absorber lugs should ensure that there is no motion interference between the upper control arm and the shock absorber when the suspension system is working normally. The ends of the crossed arms are provided with pin holes and are connected to the vehicle body or subframe through pins and bushings. The pin holes of the two crossed arms should be coaxially arranged. The shock absorber assembly (3050) is used to mitigate road impact and reduce vibration amplitude, and includes a cylindrical shock absorber and a coil spring, which are coaxially arranged. A shock absorber support rod is provided at the bottom of the shock absorber assembly, and lugs are provided at the end of the support rod and the top of the shock absorber. The lugs are respectively connected to the shock absorber lugs of the upper control arm and the vehicle body through pins.

6. A highly integrated driving unit integrating active variable kingpin lateral offset function and kingpin steering function according to claim 5, characterized in that: The active variable offset system (4000) is characterized by comprising: The execution assembly (4010) is used to drive the front and rear swing arms to move and realize the active variable offset function of the travel unit. The whole is an irregular cube, including a first housing, a second housing, an execution motor, a worm shaft, a worm wheel, a driving gear shaft and a driven gear shaft. The execution assembly is connected to the front, middle and rear execution assembly bosses on the steering knuckle through screws through the through holes provided on the first housing and the second housing. The bottom of the execution assembly is provided with a front output shaft and a rear output shaft, both of which are provided with shaft shoulders, splines and threads in sequence. The front and rear output shafts respectively pass through the front and rear gear shaft through holes provided on the support arms of the active variable offset system of the steering knuckle, and are axially fixed through the shaft shoulders. The front swing arm (4020) and the rear swing arm (4030) are used to transmit the torque output by the actuator assembly to the front and rear lower control arm ball head seats; the front swing arm and the rear swing arm are both rod-shaped as a whole, and are provided with spline grooves on the top of the wheel side, which are respectively connected to the front and rear output shafts of the actuator through splines and nuts, and are provided with threaded holes on the bottom of the body side, which are respectively connected to the front and rear lower control arm ball head seats through ball joints.

7. The active variable offset system (4000) according to claim 6, characterized in that: The execution assembly (4010) is characterized by comprising: The first shell (4011) and the second shell (4012) are both irregular cubes, and are respectively provided with empty slots on the vehicle body side and the wheel side to ensure the normal meshing of the actuator motor, worm shaft, worm wheel, driving gear shaft and driven gear shaft, which are respectively the actuator motor slot, worm shaft slot, worm wheel slot, driving gear shaft slot and driven gear shaft slot, wherein the rear part of the actuator motor slot is provided with an actuator motor through hole, the top of the driving gear shaft slot, the top of the driven gear shaft slot and the front part of the worm shaft slot should all have good processing surfaces to ensure the matching characteristics of the bearing bush, the first shell and the second shell are both provided with front, middle and rear three mounting through holes connected to the steering knuckle by screws, the three mounting through holes are each provided with a boss on the vehicle body side of the second shell, the front mounting through hole is installed on the corresponding steering knuckle lug, and the rear mounting through hole is the same through hole as the actuator motor through hole. The execution motor (4013) is a brushless DC motor, the tail of the stator is provided with a lug, a mounting through hole is provided on the lug, and the lug is fixedly connected to the rear mounting through hole of the first housing and the rear mounting through hole of the second housing by screws, and the rotor is provided with a flat keyway; A worm shaft (4014) is provided with a worm in the middle, a flat keyway is provided at the tail to be connected with the flat keyway of the actuator motor, and the head has a good processing surface to ensure the matching characteristics, and is matched with the worm shaft grooves of the first housing and the second housing through a bearing bush; A worm wheel (4015) meshes with the worm on the worm shaft and has a spline groove at the center; A driving gear shaft (4016) is provided with a spur gear in the middle, the spur gear is provided with shaft shoulders at the top and bottom, and both have good machined surfaces to ensure matching characteristics, the top is matched with the worm shaft groove of the first housing and the second housing through a bearing bush, and the bottom is matched with the through hole of the front gear shaft of the steering knuckle, and the top and bottom are further provided with splines and threads, wherein the top of the driving gear shaft is fixedly connected with the worm gear through a spline and a nut, and the bottom extends out of the first housing and the second housing as the front output shaft, and is fixedly connected with the spline groove of the front swing arm through a spline and a nut; The driven gear shaft (4017) has a spur gear in the upper middle part which meshes with the spur gear of the driving gear shaft. The spur gear is provided with shaft shoulders at the top and bottom, and both should have good matching surfaces to ensure matching characteristics. The top is matched with the worm shaft groove of the first housing and the second housing through a bearing bush, and the bottom is matched with the through hole of the rear gear shaft of the steering knuckle. The bottom is further provided with splines and threads, extending out of the first housing and the second housing, serving as the rear output shaft, and is fixedly connected to the spline groove of the rear swing arm through a spline and a nut.

8. The active variable offset system (4000) according to claim 6, characterized in that: The active variable offset system can ensure that the lateral offset of the kingpin axis is reduced to zero, and no motion interference occurs during operation; The design lengths and initial angles of the front swing arm and the rear swing arm should ensure that during the process of actively changing the offset, the angles of the front and rear lower control arms change to a certain extent while the camber angle of the wheel does not change.

9. The highly integrated driving unit integrating active variable kingpin lateral offset function and kingpin steering function according to claim 1, characterized in that: The highly integrated driving unit can realize an active variable offset control method for a steering failure process, which is characterized by: S0: Start; S1: A control unit detects a fault signal of the steering system; S2: The control unit determines whether there is a fault in the steering system. If there is a fault, it executes S3. If there is no fault, it returns to S1. S3: The control unit deactivates the steering system of the faulty wheel; S4: The control unit enables the differential fault-tolerant control of the faulty wheel, that is, the driving and braking longitudinal force steering fault-tolerant control; S5: The control unit activates the active variable offset system of the non-faulty wheel to actively reduce the lateral offset of the non-faulty wheel; S6: End; The differential fault-tolerant control, that is, the longitudinal force control of the wheel, generates a steering torque that forces the wheel to rotate around the kingpin axis, thereby achieving tracking control of the target wheel angle and realizing the differential steering function; the steering torque is proportional to the product of the longitudinal force of the wheel and the kingpin offset.

10. The highly integrated driving unit integrating active variable kingpin lateral offset function and kingpin steering function according to claim 1, characterized in that: The highly integrated driving unit can realize an active variable offset control method for a non-steering fault process, which is characterized by: When there is no steering failure, the active variable offset system of the left and right driving units can be controlled according to the current vehicle handling stability control requirements, and the kingpin lateral offset can be increased or decreased at the same time, which can improve the steering flexibility in large turning angle conditions during low-speed driving and the straight-line driving stability during driving and braking during high-speed driving.

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