A multi-axis steering system with multi-mode steering and a control method thereof

Abstract

The present application relates to the field of vehicle steering systems and discloses a multi-axis steering system with multi-mode steering and a control method thereof. The multi-axis steering system includes a control assembly and multiple steering assemblies, each of which is mounted corresponding to each axle. Each steering assembly includes: a steering gear fixed to the axle housing; a straight tie rod, one end of which is hinged to the steering arm of the steering gear and the other end is hinged to the lower arm of the steering knuckle on either side of the axle; and a transverse tie rod, both ends of which are hinged to the upper arms of the two steering knuckles of the axle. The control assembly is connected to each steering gear, and is used to receive steering commands from the driver and determine the steering angle of each axle based on the steering commands, thereby controlling the steering arm of the steering gear on each axle to rotate to its corresponding target angle. This method eliminates the need for a steering knuckle angle sensor, thereby reducing the production cost of the multi-axis steering system.

Description

Technical Field

[0001] The present invention relates to the field of vehicle steering systems, and in particular to a multi-axis steering system with multi-mode steering and a control method thereof. Background Art

[0002] At present, in order to meet the various steering conditions of multi-axle vehicles such as commercial vehicles and heavy trucks during road driving and site transfer, and to meet the requirements of vehicle handling stability, cornering ability, maneuverability, driving safety, etc., the industry is committed to realizing multi-mode steering in multi-axle steering systems, such as making the multi-axle steering system have the functions of single-group steering, all-wheel steering and oblique steering at the same time.

[0003] In existing technology, to achieve the aforementioned multi-mode steering, a multi-axle steering system requires independent steering control for each axle. Multi-axle steering systems with multi-mode steering typically connect steering cylinders to each axle, each with its own independent control circuit. The steering angle of each axle is controlled by controlling the corresponding cylinder.

[0004] However, to ensure accurate steering of each axle, a steering angle sensor must be installed at the steering knuckle of each wheel to sense the wheel's rotation angle, enabling precise closed-loop steering control. Because steering angle sensors are expensive, vehicles with a large number of axles require a larger number of them, leading to higher production costs for the steering system. Summary of the Invention

[0005] The present application provides a multi-axis steering system with multi-mode steering and a control method thereof, which can eliminate the angle sensor at the steering knuckle, thereby reducing the production cost of the multi-axis steering system.

[0006] In the first aspect, an embodiment of the present application provides a multi-axis steering system with multi-mode steering, which includes a control component and multiple groups of steering components, and the multiple groups of steering components are installed one by one corresponding to each axle, and each group of steering components includes: a steering gear, fixed to the shell of the axle; a straight tie rod, one end of which is hinged to the steering vertical arm of the steering gear, and the other end is hinged to the lower arm of the steering knuckle on either side of the axle; a transverse tie rod, both ends of which are respectively hinged to the upper arms of the two steering knuckles of the axle; the control component is connected to each of the steering gears, and is used to receive the driver's steering command and obtain the steering angle of each axle according to the steering command, and control the steering vertical arm of the steering gear of each axle to rotate to its corresponding target angle.

[0007] By adopting the above embodiment, when the vehicle needs to turn, the driver issues a steering command. Upon receiving the steering command, the control component determines the steering angle of each axle based on the steering command and then controls the corresponding steering arms of each axle to rotate to the target angle. The steering arm, via its corresponding straight tie rod, rotates the lower arm of one steering knuckle. The upper arm of that knuckle, via the tie rod, rotates the other knuckle to the same angle. Under the control of the control component, the steering arm of the steering gear can achieve precise control of its rotation angle. Since both the straight tie rod and the tie rod are rigid components, precise control of the steering arm's rotation angle also precisely controls the steering knuckle's rotation angle. This eliminates the need for installing a steering knuckle angle sensor at the knuckle, thereby reducing the production cost of multi-axis steering systems.

[0008] In combination with the first aspect, in one embodiment, the steering gear is an electro-hydraulic steering gear, and the control component includes: a control unit, which is electrically connected to the electro-hydraulic steering gear of each axle, for receiving the driver's steering instructions, and obtaining the steering angle of each axle according to the steering instructions, and sending corresponding steering angle instructions to the electro-hydraulic steering gear of each axle; a hydraulic pump station, which is electrically connected to the control unit and is allocated with multiple hydraulic pipelines, and the multiple hydraulic pipelines are respectively connected to the hydraulic oil circuits of the oil inlet of the electro-hydraulic steering gear of each axle.

[0009] With this embodiment, when the control unit receives a steering command from the driver, it calculates the steering angle of each axle based on the command. The control unit then issues a steering command to the electro-hydraulic steering gear on each axle. Simultaneously, the hydraulic pump station supplies hydraulic oil to each steering gear through various hydraulic oil circuits, causing the steering drop arm of the electro-hydraulic steering gear to rotate to the target angle. Due to the high control accuracy and large steering torque of the electro-hydraulic steering gear, the steering angle of each axle can be precisely controlled.

[0010] In combination with the first aspect, in one embodiment, the number of axles is N, N is an even number, and N≥2, and the hydraulic pump station includes N / 2 hydraulic pumps, and the oil outlet of each hydraulic pump is connected to a diverter valve, each diverter valve diverts two hydraulic oil circuits, and the two hydraulic oil circuits are respectively connected to the two adjacent steering gear oil inlets.

[0011] By adopting the above embodiment, for an even number of axles, each two adjacent axles use the same hydraulic pump, thereby reducing the number of hydraulic pumps used. Furthermore, because the diverter valve can be manually adjusted to adjust the flow rate between the two hydraulic oil circuits, the diverter valve ratio can be adjusted based on the ratio of the steering angles of the two adjacent axles, ensuring that the steering speeds of the two adjacent axles are similar, thereby effectively maintaining steering angle coordination during the steering process.

[0012] In combination with the first aspect, in one embodiment, the number of axles is N, N is an odd number, and N≥3, and the hydraulic pump station includes ((N-1) / 2)+1 hydraulic pumps, wherein the oil outlets of (N-1) / 2 hydraulic pumps are connected to a diverter valve, each diverter valve diverts two hydraulic oil circuits, and the two hydraulic oil circuits are respectively connected to the oil inlets of two adjacent steering gears, and the oil outlet of the remaining hydraulic pump is connected to the oil inlet of the remaining steering gear through the hydraulic oil circuit.

[0013] By adopting the above embodiment, two adjacent axles can share one hydraulic pump as much as possible, thereby reducing the number of hydraulic pumps used.

[0014] In combination with the first aspect, in one embodiment, the number of axles is N, and N≥2, the hydraulic pump station includes N hydraulic pumps, and the oil outlets of the N hydraulic pumps are respectively connected to the oil inlets of the N steering gears through hydraulic oil circuits.

[0015] By adopting the above embodiment, each axle corresponds to a hydraulic pump, so that each axle can select the flow corresponding to its own hydraulic pump according to actual needs, and can more accurately control the flow of the hydraulic oil circuit corresponding to each steering gear.

[0016] In combination with the first aspect, in one embodiment, it also includes multiple power-assisted cylinders, which are installed one-to-one with each axle. Each power-assisted cylinder is connected in parallel to its corresponding electro-hydraulic steering gear. The end of the power-assisted cylinder housing is hinged to the axle housing, and the end of the telescopic rod is hinged to the lower arm of the steering knuckle on the side away from the straight pull rod. The swing direction of the steering vertical arm of the electro-hydraulic steering gear is consistent with the telescopic direction of the telescopic rod of the power-assisted cylinder.

[0017] By adopting the above embodiment, when the steering gear drives the lower arm of the steering knuckle on one side to rotate through the straight pull rod, the telescopic rod of the power-assisting cylinder can synchronously drive the lower arm of the steering knuckle on the other side to rotate in the same direction, thereby assisting the steering of the axle, thereby further improving the steering performance of the steering system.

[0018] On the second aspect, an embodiment of the present application also provides a control method for a multi-axis steering system with multi-mode steering, which includes the following steps: a control component receives a steering command from a driver; the control component derives the turning angle of each axle based on the steering command; the control component controls the steering vertical arm of each axle steering gear to rotate to its corresponding target angle based on the turning angle of each axle; the steering vertical arm of the steering gear drives the lower arm of the steering knuckle on one side to rotate through its corresponding straight pull rod, and the upper arm of the steering knuckle on this side drives the upper arm of the steering knuckle on the other side to rotate to the same angle through the transverse pull rod.

[0019] In combination with the second aspect, in one embodiment, when the driver's steering command is a single-group steering mode, the control component controls the steering arms of the steering gears of each front axle to rotate to their corresponding target angles, and the target angles of each front axle conform to the Ackermann angle relationship, and the steering arms of the steering gears of each rear axle do not rotate.

[0020] In combination with the second aspect, in one embodiment, when the driver's steering command is the all-wheel steering mode, the control component controls the steering arms of each steering gear of the front axle to rotate to their respective corresponding first target angles, and the first target angles of each axle of the front axle conform to the Ackermann angle relationship; the control component controls the steering arms of each steering gear of the rear axle to rotate to their respective corresponding second target angles, the second target angle and the first target angle are opposite in direction, and the second target angles of each axle of the rear axle conform to the Ackermann angle relationship.

[0021] In combination with the second aspect, in one embodiment, when the driver's steering instruction is a diagonal mode, the control component controls the steering drop arms of the steering machines of all axles to rotate to a target angle, and the target angles of each axle are the same.

[0022] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0023] When the vehicle needs to steer, the driver issues a steering command. Upon receiving the command, the control unit determines the steering angles of each axle based on the steering command. It then issues commands to each steering gear, rotating the steering arms of each gear to the target angles. The steering arms, via their corresponding straight tie rods, rotate the lower arm of one steering knuckle. The upper arm of that knuckle, via the tie rods, rotates the other knuckle to the same angle. Under the control of the control unit, the steering arms of the steering gears can achieve precise control of their rotation angles. Because both the straight tie rods and the tie rods are rigid components, precise control of the steering arm angle also ensures precise control of the steering knuckle angle. This eliminates the need for knuckle angle sensors, reducing the production cost of multi-axle steering systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 This is an overall schematic diagram of the steering structure of one of the axles in the embodiment of the present application;

[0026] Figure 2 A top view of the steering structure of one of the axles in the embodiment of the present application;

[0027] Figure 3 This is a hydraulic principle diagram of the steering system in the embodiment of the present application;

[0028] Figure 4 This is a schematic diagram of the state of the wheels in a single-group steering mode in an embodiment of the present application;

[0029] Figure 5 This is a schematic diagram of the state of the wheels in the all-wheel steering mode in an embodiment of the present application;

[0030] Figure 6 This is a schematic diagram of the status of the wheels in the diagonal driving mode in an embodiment of the present application.

[0031] In the picture:

[0032] 1. Control assembly; 11. Control unit; 12. Hydraulic pump station; 121. Hydraulic pump;

[0033] 2. Steering assembly; 21. Steering gear; 211. Steering drop arm; 22. Straight tie rod; 23. Transverse tie rod;

[0034] 3. Diverter valve;

[0035] 4. Power cylinder;

[0036] 5. Axle; 51. Lower arm; 52. Upper arm. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] An embodiment of the present application provides a multi-axis steering system with multi-mode steering and a control method thereof. Compared with the prior art in which a steering angle sensor needs to be installed at each steering knuckle, the steering system in the embodiment of the present application can eliminate the steering angle sensor at the steering knuckle, thereby reducing the production cost of the multi-axis steering system.

[0039] Reference Figure 1-Figure 3The present application provides an embodiment of a multi-axis steering system with multi-mode steering, which includes a control assembly 1 and multiple sets of steering assemblies 2. The number of steering assemblies 2 is the same as the number of axles 5, and the multiple sets of steering assemblies 2 are installed in a one-to-one correspondence with each axle 5. Each set of steering assemblies 2 includes a steering gear 21, a straight tie rod 22, and a transverse tie rod 23. Specifically, the steering gear 21 is fixed to the housing of the axle 5. One end of the straight tie rod 22 is hinged to the steering arm 211 of the steering gear 21, and the other end is hinged to the lower arm 51 of the steering knuckle on either side of the axle 5. The ends of the transverse tie rod 23 are respectively hinged to the upper arms 52 of the two steering knuckles of the axle 5. The control assembly 1 is connected to each steering gear 21, and is used to receive the driver's steering command and obtain the steering angle of each axle 5 based on the steering command, and control the steering arm 211 of the steering gear 21 of each axle 5 to rotate to its corresponding target angle.

[0040] When the vehicle needs to turn, the driver issues a steering command. Upon receiving the steering command, the control assembly 1 calculates the steering angle of each axle 5 based on the steering command and then issues a command to each steering gear 21, causing the steering arm 21 of each steering gear 21 to rotate to the target angle. The steering arm 211, via its corresponding straight tie rod 22, rotates the lower arm 51 of one steering knuckle. The upper arm 52 of that knuckle, via the tie rod 23, rotates the other knuckle to the same angle. Under the control of the control assembly 1, the steering arm 211 of the steering gear 21 can achieve precise control of its rotation angle. Because both the straight tie rod 22 and the tie rod 23 are rigid components, precise control of the steering arm 211's rotation angle also ensures precise control of the steering knuckle's rotation angle. This eliminates the need for installing a steering knuckle angle sensor, thereby reducing the production cost of the multi-axis steering system.

[0041] Further, refer to Figure 2 and Figure 3 In the preferred embodiment of the present application, the steering gear 21 adopts an electro-hydraulic steering gear 21. Accordingly, the control component 1 includes a control unit 11 ( Figure 2 The control unit 11 is electrically connected to the electro-hydraulic steering gear 21 of each axle 5 and receives steering commands from the driver. Based on these commands, the control unit 11 determines the steering angle of each axle 5 and issues corresponding steering angle commands to the electro-hydraulic steering gear 21 of each axle 5. The hydraulic pump station 12 is equipped with multiple hydraulic lines, which are connected to the hydraulic oil circuits of the electro-hydraulic steering gear 21 of each axle 5.

[0042] By adopting the above embodiment, when the control unit 11 receives a steering command from the driver, it calculates the steering angle of each axle 5 based on the driver's command. The control unit 11 then issues a steering command to the electro-hydraulic steering gear 21 of each axle 5. Simultaneously, the hydraulic pump station 12 supplies hydraulic oil to the oil inlet of each steering gear 21 through various hydraulic oil circuits. The steering drop arm 211 of the electro-hydraulic steering gear 21 rotates to the target angle according to the steering command. Due to the high control accuracy and large steering torque of the electro-hydraulic steering gear 21, the steering angle of each axle 5 can be precisely controlled.

[0043] As can be seen from the above, the hydraulic pump station 12 in the embodiment of the present application allocates multiple hydraulic oil circuits. In one embodiment of the embodiment of the present application, when the number of axles 5 is N, N is an even number, and N ≥ 2, the hydraulic pump station 12 includes N / 2 hydraulic pumps 121, and the oil outlet of each hydraulic pump 121 is connected to a diverter valve 3. Each diverter valve 3 diverts two hydraulic oil circuits, and the two hydraulic oil circuits are respectively connected to the oil inlets of two adjacent steering gears 21. For example, when the number of axles 5 in the embodiment of the present application is 4, there are two axles 5 on the front axle and two axles 5 on the rear axle. In this case, the two steering gears 21 on the front axle share one diverter valve 3, and the two steering gears 21 on the rear axle share one diverter valve 3. The hydraulic station includes two hydraulic pumps 121, and the two hydraulic pumps 121 are respectively connected to the two diverter valves 3. In actual implementation, in order to further make the hydraulic pumps 121 more compact, the two hydraulic pumps 121 can also be replaced by a double pump. It can be seen that for the case of an even number of axles 5, every two adjacent axles 5 use the same hydraulic pump 121, thereby reducing the number of hydraulic pumps 121 used and the space occupied by the hydraulic pump station 12. Due to the reduction in the number of hydraulic pumps 121, the cost of the steering system is reduced.

[0044] It should be noted that the diverter valve 3 in the embodiment of the present application can be set to a diversion ratio as needed, so that the two hydraulic oil circuits diverted by the diverter valve 3 are diverted according to a certain flow ratio. When the steering system performs a steering operation, in which a certain angle ratio of two adjacent axles 5 accounts for the majority, the diversion ratio of the diverter valve 3 can be set in advance to the angle ratio. For example, in most cases, in which the angle ratio of two adjacent axles 5 is 4:3, then the diversion ratio of the diverter valve 3 corresponding to the two axles 5 can be set to 4:3. Through such a setting, the steering speeds of the two adjacent axles 5 are close, thereby better maintaining the angle coordination during the steering process. Similarly, if in most cases, the steering system adopts an oblique mode, that is, the angles of each axle 5 are the same, at this time, the diversion ratio of the diverter valve 3 is 1:1, thereby better ensuring that the steering speeds of the two adjacent axles 5 are close, and better achieving angle coordination in the oblique mode.

[0045] In the embodiment of the present application, the hydraulic pump station 12 allocates multiple hydraulic oil circuits. In another embodiment of the embodiment of the present application, when the number of axles 5 is N, N is an odd number, and N ≥ 3, the hydraulic pump station 12 includes ((N-1) / 2)+1 hydraulic pumps 121, wherein the oil outlets of the (N-1) / 2 hydraulic pumps 121 are all connected to the diverter valve 3, and each diverter valve 3 diverts two hydraulic oil circuits, and the two hydraulic oil circuits are respectively connected to the oil inlets of two adjacent steering gears 21, and the oil outlet of the remaining hydraulic pump 121 is connected to the oil inlet of the remaining steering gear 21 through the hydraulic oil circuit. For example, when the number of axles 5 is 5, there are 2 axles 5 on the front axle and 3 axles 5 on the rear axle. Then the hydraulic pump station 12 includes 3 hydraulic pumps 121, wherein 2 hydraulic pumps 121 are both connected to the diverter valve 3, and the remaining hydraulic pump 121 is directly connected to the steering gear 21. Specifically, the first hydraulic pump 121 is connected to the diverter valve 3, which then branches out into two hydraulic oil circuits, each of which is connected to the two steering gears 21 of the front axle. The second hydraulic pump 121 is connected to the diverter valve 3, which then branches out into two hydraulic oil circuits, each of which is connected to the two adjacent steering gears 21 of the rear axle. The third hydraulic pump 121 is directly connected to the remaining steering gear 21 via a hydraulic oil circuit. By adopting the above embodiment, as many adjacent axles 5 as possible can share one hydraulic pump 121, thereby reducing the number of hydraulic pumps 121 used and the space occupied by the hydraulic pump station 12. Due to the reduction in the number of hydraulic pumps 121, the cost of the steering system is reduced.

[0046] In the embodiment of the present application, the hydraulic pump station 12 allocates multiple hydraulic oil circuits. In another embodiment, when the number of axles 5 is N, and N ≥ 2, the hydraulic pump station 12 includes N hydraulic pumps 121, and the oil outlets of the N hydraulic pumps 121 are respectively connected to the oil inlets of the N steering gears 21 through hydraulic oil circuits. For example, if the number of axles 5 is 4, there are 4 hydraulic pumps 121, and the oil outlets of the four hydraulic pumps 121 are respectively connected to the oil inlets of the four steering gears 21 through hydraulic oil circuits. By adopting the above embodiment, each axle 5 corresponds to a hydraulic pump 121, so that each axle 5 can select the flow rate corresponding to its own hydraulic pump 121 according to actual needs, and can more accurately control the flow rate of the hydraulic oil circuit corresponding to each steering gear 21.

[0047] Further, refer to Figure 1-Figure 3The steering system of the present application further includes a plurality of power-assisting cylinders 4, which are mounted one-to-one in correspondence with each axle 5. Each power-assisting cylinder 4 is connected in parallel to its corresponding electro-hydraulic steering gear 21. The end of the power-assisting cylinder 4 housing is hinged to the housing of the axle 5, and the end of the telescopic rod is hinged to the lower arm 51 of the steering knuckle on the side away from the straight tie rod 22. The swing direction of the steering drop arm 211 of the electro-hydraulic steering gear 21 is consistent with the telescopic rod extension direction of the power-assisting cylinder 4. With this arrangement, when the steering gear 21 drives the lower arm 51 of one steering knuckle to rotate via the straight tie rod 22, the telescopic rod of the power-assisting cylinder 4 can simultaneously drive the lower arm 51 of the other steering knuckle to rotate in the same direction, thereby assisting the steering of the axle 5 and further improving the steering performance of the steering system.

[0048] Specifically, the electro-hydraulic steering gear 21 includes an oil inlet, an oil outlet, a first parallel interface, and a second parallel interface. The power-assisting cylinder 4 includes a first cylinder interface and a second cylinder interface. The oil inlet is used to supply oil to the electro-hydraulic steering gear 21, and the oil outlet is used to return oil to the hydraulic pump station 12. The first parallel interface is connected to the first cylinder interface, and the second parallel interface is connected to the second cylinder interface.

[0049] When the steering arm 211 of the electro-hydraulic steering gear 21 rotates in a certain direction, the hydraulic oil of the hydraulic pump 121 enters the electro-hydraulic steering gear 21 from the oil inlet, and the hydraulic oil flows back to the hydraulic pump station 12 from the oil outlet. The hydraulic oil of the first parallel interface enters the first cylinder interface of the power-assisted oil cylinder 4, and the hydraulic oil at the second cylinder interface enters the second parallel interface. The telescopic rod of the power-assisted oil cylinder 4 is extended and retracted in the same direction as that of the steering arm 211. When the steering arm 211 of the electro-hydraulic steering gear 21 rotates in the opposite direction, the hydraulic oil of the hydraulic pump 121 enters the electro-hydraulic steering gear 21 from the oil inlet, and the hydraulic oil flows back to the hydraulic pump station 12 from the oil outlet. The hydraulic oil of the first parallel interface enters the second cylinder interface of the power-assisted oil cylinder 4, and the hydraulic oil at the second cylinder interface enters the first parallel interface. The telescopic rod of the power-assisted oil cylinder 4 is extended and retracted in the same direction as that of the steering arm 211.

[0050] Based on the above-mentioned multi-axis steering system with multi-mode steering, the present application also discloses a control method for the multi-axis steering system with multi-mode steering, which is characterized by comprising the following steps:

[0051] S1. Control component 1 receives a steering instruction from a driver.

[0052] S2. The control component 1 obtains the turning angle of each axle 5 according to the steering instruction.

[0053] S3. The control component 1 controls the steering drop arm 211 of the steering gear 21 of each axle 5 to rotate to the corresponding target angle according to the rotation angle of each axle 5.

[0054] S4. The steering vertical arm 211 of the steering gear 21 drives the lower arm 51 of one steering knuckle to rotate through its corresponding straight tie rod 22, and the upper arm 52 of the steering knuckle on that side drives the upper arm 52 of the other steering knuckle to rotate the same angle through the transverse tie rod 23.

[0055] Since the steering system is a multi-mode steering system, it specifically includes the following three modes:

[0056] Mode 1: When the driver's steering command is a single-group steering mode, the steering system is controlled as follows:

[0057] The control component 1 controls the steering arms 211 of the steering gears 21 of each front axle 5 to rotate to their respective corresponding target angles, and the target angles of each front axle 5 conform to the Ackermann angle relationship, and the steering arms 211 of the steering gears 21 of each rear axle 5 do not rotate.

[0058] Combine Figure 3 and Figure 4 , Figure 4 The small and medium rectangles represent wheels. Opposite sets of wheels are mounted at both ends of an axle. The front axle includes two axles 5, and the rear axle includes two axles 5. When the driver's steering command is for single-set steering mode, the target angles of the two axles 5 on the front axle conform to the Ackermann angle relationship, and the steering gears 21 of the two axles 5 on the rear axle do not operate, thereby achieving single-set steering.

[0059] Mode 2: When the driver's steering command is all-wheel steering mode, the steering system is controlled as follows:

[0060] The control component 1 controls the steering drop arms 211 of the steering gears 21 of the front axles to rotate to their respective corresponding first target angles, and the first target angles of the front axles 5 conform to the Ackerman angle relationship.

[0061] The control component 1 controls the steering drop arms 211 of the steering gears 21 of the rear axles to rotate to their respective corresponding second target angles. The second target angles are opposite to the first target angles, and the second target angles of the rear axles 5 conform to the Ackerman angle relationship.

[0062] Combine Figure 3 and Figure 5 , Figure 5 The small and medium rectangles represent wheels. Opposite sets of wheels are mounted at both ends of an axle. The front axle includes two axles 5, and the rear axle includes two axles 5. When the driver's steering command is for all-wheel steering mode, the target angles of the two axles 5 on the front axle conform to the Ackermann angle relationship. The steering drop arms 211 of the steering gears 21 of the two axles 5 on the rear axle rotate in the opposite direction to that of the front axle, and the target angles of the two axles 5 on the rear axle conform to the Ackermann angle relationship, thereby achieving all-wheel steering.

[0063] Mode 3: When the driver's steering command is the oblique mode, the steering system is controlled as follows:

[0064] The control assembly 1 controls the steering drop arms 211 of the steering gears 21 of all axles 5 to rotate to a target angle, and the target angles of each axle are the same.

[0065] Combine Figure 3 and Figure 6 , Figure 6 The small and medium rectangles represent wheels. Opposite sets of wheels are mounted at both ends of an axle. The front axle includes two axles 5, and the rear axle includes two axles 5. When the driver's steering command is for a diagonal steering mode, the control assembly 1 controls the steering drop arms 211 of the steering gears 21 of the four axles 5 to rotate to the same target angle. The steering angles of each axle 5 are the same, thus achieving a diagonal steering mode.

[0066] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0067] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0068] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A multi-axis steering system with multi-mode steering, characterized in that: include: A control assembly (1) and a plurality of steering assemblies (2), wherein the plurality of steering assemblies (2) are installed in a one-to-one correspondence with each axle (5), and each steering assembly (2) includes: A steering gear (21) fixed to the housing of the axle (5); A straight pull rod (22), one end of which is hinged to the steering vertical arm (211) of the steering gear (21), and the other end of which is hinged to the lower arm (51) of the steering knuckle on either side of the axle (5); A tie rod (23), both ends of which are respectively hinged to the upper arms (52) of the two steering knuckles of the axle (5); The control component (1) is connected to each of the steering machines (21) and is used to receive a steering instruction from a driver and obtain the turning angle of each axle (5) according to the steering instruction, and control the steering drop arm (211) of the steering machine (21) of each axle (5) to rotate to a corresponding target angle. The steering gear (21) is an electro-hydraulic steering gear (21), and the control component (1) comprises: A control unit (11) is electrically connected to the electro-hydraulic steering machine (21) of each axle (5), and is used to receive a steering instruction from a driver, obtain a steering angle of each axle (5) according to the steering instruction, and send a corresponding steering angle instruction to the electro-hydraulic steering machine (21) of each axle (5); A hydraulic pump station (12) is electrically connected to the control unit (11) and is provided with multiple hydraulic pipelines, each of which is connected to the hydraulic oil circuits of the oil inlet of the electro-hydraulic steering gear (21) of each axle (5); The number of axles (5) is N, N is an even number, and N≥2. The hydraulic pump station (12) includes N / 2 hydraulic pumps (121). The oil outlet of each hydraulic pump (121) is connected to a diverter valve (3). Each diverter valve (3) diverts oil into two hydraulic oil circuits. The two hydraulic oil circuits are respectively connected to the oil inlets of two adjacent steering gears (21).

2. The multi-axis steering system with multi-mode steering according to claim 1, characterized in that: The number of axles (5) is N, N is an odd number, and N≥3. The hydraulic pump station (12) includes ((N-1) / 2)+1 hydraulic pumps (121), wherein the oil outlets of (N-1) / 2 hydraulic pumps (121) are all connected to a diverter valve (3), and each diverter valve (3) diverts two hydraulic oil circuits, and the two hydraulic oil circuits are respectively connected to the oil inlets of two adjacent steering gears (21), and the oil outlet of the remaining hydraulic pump (121) is connected to the oil inlet of the remaining steering gear (21) through the hydraulic oil circuit.

3. The multi-axis steering system with multi-mode steering according to claim 1, characterized in that: The invention also includes a plurality of power-assisting oil cylinders (4), which are installed one-to-one with each axle (5). Each power-assisting oil cylinder (4) is connected in parallel to its corresponding electro-hydraulic steering gear (21). The end of the power-assisting oil cylinder (4) housing is hinged to the axle (5) housing. The end of the telescopic rod is hinged to the lower arm (51) of the steering knuckle on the side away from the straight pull rod (22). The swing direction of the steering vertical arm (211) of the electro-hydraulic steering gear (21) is consistent with the telescopic direction of the telescopic rod of the power-assisting oil cylinder (4).

4. A control method for a multi-axis steering system based on the multi-mode steering according to any one of claims 1 to 3, characterized in that: The following steps are involved: The control component (1) receives a steering instruction from the driver; The control component (1) obtains the turning angle of each axle (5) according to the steering instruction; The control component (1) controls the steering drop arm (211) of the steering gear (21) of each axle (5) to rotate to a corresponding target angle according to the rotation angle of each axle (5); The steering vertical arm (211) of the steering gear (21) drives the lower arm (51) of one steering knuckle to rotate through its corresponding straight tie rod (22), and the upper arm (52) of the steering knuckle on the side drives the upper arm (52) of the other steering knuckle to rotate by the same angle through the transverse tie rod (23).

5. The control method of a multi-axis steering system with multi-mode steering according to claim 4, characterized in that: When the driver's steering command is a single-group steering mode, the control component (1) controls the steering drop arms (211) of the steering machines (21) of the front axles (5) to rotate to their respective corresponding target angles, and the target angles of the front axles (5) conform to the Ackerman angle relationship, while the steering drop arms (211) of the steering machines (21) of the rear axles (5) do not rotate.

6. The control method of a multi-axis steering system with multi-mode steering according to claim 4, characterized in that: When the driver's steering command is an all-wheel steering mode, the control component (1) controls the steering drop arms (211) of each steering machine (21) of the front axle to rotate to their respective corresponding first target angles, and the first target angles of each axle (5) of the front axle conform to the Ackerman angle relationship; The control component (1) controls the steering drop arms (211) of the steering gears (21) of the rear axles to rotate to respective corresponding second target angles, the second target angles being opposite to the first target angles, and the second target angles of the rear axles (5) conforming to an Ackerman angle relationship.

7. The multi-axis steering system with multi-mode steering and the control method thereof according to claim 4, characterized in that: When the driver's steering instruction is a diagonal mode, the control component (1) controls the steering drop arms (211) of the steering machines (21) of all axles (5) to rotate to a target angle, and the target angles of each axle (5) are the same.

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