A wheel-leg robot and its leg joint driving device

Abstract

The present invention discloses a wheel-leg robot and a leg joint driving device thereof, belonging to the technical field of wheel-leg robots, and including a hydraulic control system; the hydraulic control system includes a hydraulic cylinder, a piston rod, a main oil circuit, a secondary oil circuit, a servo motor and a hydraulic pump; a load-bearing chamber and a non-load-bearing chamber are arranged in the hydraulic cylinder; the piston rod separates the load-bearing chamber and the non-load-bearing chamber; the servo motor is used to drive the hydraulic pump; the non-load-bearing chamber, the main oil circuit, the hydraulic pump, the secondary oil circuit and the load-bearing chamber are connected in sequence; the extension of the piston rod relative to the hydraulic cylinder changes with the change of the hydraulic oil capacity in the load-bearing chamber and the non-load-bearing chamber. The wheel-leg robot and the leg joint driving device of the present invention have no overflow loss, no throttling loss, save system power, and the hydraulic system has high transmission efficiency, high energy utilization, good buffering performance and long service life.

Description

Technical Field

[0001] The present invention belongs to the technical field of wheel-legged robots, and in particular relates to a wheel-legged robot and a leg joint driving device thereof. Background Art

[0002] Wheel-legged robots are robots with wheels added to the ends of their legs. This type of robot fully combines the advantages of wheels and legs, and can not only pass through vehicle roads quickly and efficiently, but also use the gait of the legs to climb over obstacles and pass through non-structural environments. Compared with foot-type robots, they have a faster travel speed in road environments, so the research on wheel-legged robots has received more and more attention.

[0003] At present, the research on wheel-leg robots is mainly concentrated on small wheel-leg robot platforms. The robot body and load capacity are relatively small, and a motor and a reducer combination can be used to drive the leg joints. For the leg joints of medium / large wheel-leg robots, servo valve-controlled cylinders are used for driving. The servo valve is installed on the hydraulic cylinder, and the hydraulic cylinder piston rod drives the leg joints through a connecting rod. The pressure oil of the servo valve is supplied by a centralized pump station. The output force / speed of the hydraulic cylinder is controlled by controlling the direction and size of the servo valve core opening, thereby controlling the torque / speed of the leg joints.

[0004] The use of servo valve-controlled cylinders as joint drive devices in medium / large wheel-legged robots has the following problems:

[0005] 1. In the hydraulic system that uses servo valve-controlled cylinders as the joint actuators of the wheel-legged robot, a centralized pump station is used as the power source. In order to maintain a constant system pressure, the pump station needs to use an overflow valve to overflow to maintain a constant pressure. This method causes overflow loss in the pump station, which leads to power loss in the system.

[0006] 2. The servo valve controlled cylinder achieves precise output force / speed control of the hydraulic cylinder through the throttling of the servo valve. There is a large throttling power loss, low transmission efficiency of the hydraulic system, and low effective energy utilization of the robot. Generally, when the wheel-legged robot is driving, the output torque of its joint drive device needs to overcome its own gravity and inertia, so a larger torque is required at this time, and a hydraulic actuator is required to drive it, which can achieve a higher power density ratio; but when the wheel-legged robot is performing a gait to cross an obstacle, the joint drive device only needs to overcome the weight of the leg, so the output torque of the joint drive device required at this time is relatively small. If a servo valve controlled cylinder actuator is used, a huge pressure difference will be generated at the servo valve port, resulting in a large throttling loss.

[0007] 3. The joint drive device system composed of a servo valve-controlled cylinder and a centralized pump station is complex, and the servo valve has poor resistance to oil contamination, resulting in poor reliability of the entire joint drive device.

[0008] 4. The servo valve-controlled cylinder is a rigid actuator composed of a servo valve and a hydraulic cylinder. When the wheel-legged robot encounters a protrusion while driving on the ground, it will produce an instantaneous force impact on the joint actuator. Since the servo valve-controlled cylinder has no passive buffer device, an instantaneous pressure peak will be generated inside the hydraulic cylinder under this instantaneous force impact. This pressure peak will damage the hydraulic components and seals.

[0009] 5. Once the robot system loses power, the servo valve-controlled cylinder drive device will not work normally, making it inconvenient to transport.

[0010] 6. The joint drive system composed of a servo valve-controlled cylinder and a centralized pump station is complex, and the servo valve has poor resistance to oil contamination, resulting in poor reliability of the entire joint drive system. Summary of the invention

[0011] The purpose of the present invention is to provide a wheel-legged robot and its leg joint drive device in view of the above shortcomings, and to solve the problems of how to cancel the servo valve control cylinder in the leg joint drive of medium / large wheel-legged robots to achieve no throttling loss, and at the same time improve the efficiency of the joint drive during vibration reduction during driving, improve the effective energy utilization rate of the robot, and extend the cruising time of the robot. To achieve the above purpose, the present invention provides the following technical solutions:

[0012] A wheel-leg robot leg joint drive device includes a hydraulic control system; the hydraulic control system includes a hydraulic cylinder 1, a piston rod 2, a main oil circuit, a secondary oil circuit, a servo motor 7 and a hydraulic pump 8; a load-bearing chamber 9 and a non-load-bearing chamber 10 are provided in the hydraulic cylinder 1; the piston rod 2 separates the load-bearing chamber 9 and the non-load-bearing chamber 10; the servo motor 7 is used to drive the hydraulic pump 8; the non-load-bearing chamber 10, the main oil circuit, the hydraulic pump 8, the secondary oil circuit and the load-bearing chamber 9 are connected in sequence; the elongation of the piston rod 2 relative to the hydraulic cylinder 1 changes with the change of the hydraulic oil capacity in the load-bearing chamber 9 and the non-load-bearing chamber 10.

[0013] Furthermore, the hydraulic control system also includes a first overflow valve 11 and a second overflow valve 12; the inlet of the first overflow valve 11 is connected to the main oil circuit; the outlet of the first overflow valve 11 is connected to the secondary oil circuit; the inlet of the second overflow valve 12 is connected to the secondary oil circuit; and the outlet of the second overflow valve 12 is connected to the main oil circuit.

[0014] Furthermore, the hydraulic control system also includes an oil replenishment accumulator 13; the hydraulic control system also includes a first one-way valve 14 and a second one-way valve 15; the outlet of the oil replenishment accumulator 13 is connected to the inlet of the first one-way valve 14 and the inlet of the second one-way valve 15; the outlet of the first one-way valve 14 is connected to the main oil circuit; the outlet of the second one-way valve 15 is connected to the secondary oil circuit.

[0015] Furthermore, the hydraulic control system also includes a high-pressure accumulator 16, a high-pressure oil circuit and a low-pressure oil circuit; the outlet of the oil replenishment accumulator 13 is connected to the non-load-bearing chamber 10 through the low-pressure oil circuit; the outlet of the high-pressure accumulator 16 is connected to the load-bearing chamber 9 through the high-pressure oil circuit.

[0016] Furthermore, the hydraulic control system further comprises a first solenoid valve 22 and a second solenoid valve 21; the low-pressure oil circuit comprises a fifth oil circuit 17 and a sixth oil circuit 18; the high-pressure oil circuit comprises a seventh oil circuit 19 and an eighth oil circuit 20; the second solenoid valve 21 is a two-position four-way solenoid switch valve; the second solenoid valve 21 comprises a2 port, b2 port, c2 port and d2 port; the two ends of the fifth oil circuit 17 are respectively connected to a2 port and an oil replenishment accumulator 13; the two ends of the sixth oil circuit 18 are respectively connected to b2 port and a non-load-bearing chamber 10; the two ends of the seventh oil circuit 19 are respectively connected to c2 port and a high-pressure accumulator 16; the two ends of the eighth oil circuit 20 are respectively connected to d2 port and a load-bearing chamber 9; when the second solenoid valve 21 is in a de-energized state, except that a2 port and b2 port are connected, and c2 port and d2 port are connected, the other ports are not connected; the When the second solenoid valve 21 is in the state of gaining potential, all ports are not connected; the main oil circuit includes the first oil circuit 3 and the second oil circuit 4; the secondary oil circuit includes the third oil circuit 5 and the fourth oil circuit 6; the first solenoid valve 22 is a two-position four-way solenoid switch valve; the first solenoid valve 22 includes port a1, port b1, port c1 and port d1; the two ends of the first oil circuit 3 are connected to port a1 and the non-load-bearing chamber 10 respectively; the two ends of the second oil circuit 4 are connected to port b1 and the hydraulic pump 8 respectively; the two ends of the third oil circuit 5 are connected to port c1 and the hydraulic pump 8 respectively; the two ends of the fourth oil circuit 6 are connected to port d1 and the load-bearing chamber 9 respectively; when the first solenoid valve 22 is in the state of gaining potential, except that port a1 and port b1 are connected, and port c1 and port d1 are connected, the other ports are not connected; when the first solenoid valve 22 is in the state of losing potential, all ports are not connected.

[0017] Furthermore, the hydraulic control system also includes a third solenoid valve 24; the main oil circuit includes the first oil circuit 3 and the second oil circuit 4; the secondary oil circuit includes the third oil circuit 5 and the fourth oil circuit 6; the third solenoid valve 24 is a two-position four-way solenoid switch valve; the third solenoid valve 24 includes a3 port, b3 port, c3 port and d3 port; the two ends of the first oil circuit 3 are respectively connected to the a3 port and the non-load-bearing chamber 10; the two ends of the second oil circuit 4 are respectively connected to the b3 port and the hydraulic pump 8; the two ends of the third oil circuit 5 are respectively connected to the c3 port and the hydraulic pump 8; the two ends of the fourth oil circuit 6 are respectively connected to the d3 port and the load-bearing chamber 9; when the third solenoid valve 24 is in a potential-earthing state, except that the a3 port and the b3 port are connected, and the c3 port and the d3 port are connected, the other ports are not connected; when the third solenoid valve 24 is in a potential-losing state, except that the a3 port and the d3 port are connected, the other ports are not connected.

[0018] Furthermore, the hydraulic control system further includes a second high-pressure accumulator 26 ; the second high-pressure accumulator 26 is connected to the bearing chamber 9 through an oil circuit.

[0019] Furthermore, the hydraulic control system also includes a controller and a force sensor; the force sensor, the third solenoid valve 24, and the servo motor 7 are electrically connected to the controller respectively; the force sensor is used to monitor the load signal of the piston rod 2 and transmit the load signal to the controller; the controller is used to control the switch position of the third solenoid valve 24 and the speed and direction of the servo motor 7.

[0020] Furthermore, a guide rod 27 is provided in the hydraulic cylinder 1; the piston rod 2 is hollow inside and is sleeved on the guide rod 27; the load-bearing chamber 9 is located at the top of the guide rod 27 and is surrounded by the rod portion of the piston rod 2; a guide passage 28 is provided in the guide rod 27; the guide passage 28 connects the load-bearing chamber 9 and the fourth oil circuit 6; a spring 29 is sleeved on the guide rod 27; the spring 29 is compressed between the plug portion of the piston rod 2 and the bottom of the hydraulic cylinder 1; the non-load-bearing chamber 10 is located between the rod portion of the piston rod 2 and the hydraulic cylinder 1.

[0021] Furthermore, the hydraulic control system also includes a fourth solenoid valve 30 and a motor gear control system; the main oil circuit includes the first oil circuit 3 and the second oil circuit 4; the secondary oil circuit includes the third oil circuit 5 and the fourth oil circuit 6; the fourth solenoid valve 30 is a two-position two-way solenoid switch valve; the fourth solenoid valve 30 includes an a4 port and a b4 port; the non-load-bearing chamber 10, the first oil circuit 3, the second oil circuit 4, the hydraulic pump 8, the third oil circuit 5, the fourth oil circuit 6 and the load-bearing chamber 9 are connected in sequence; the first oil circuit 3 and the second oil circuit 4 are connected to the a4 port; the third oil circuit 5 and the fourth oil circuit 6 are connected to the b4 port together; when the fourth solenoid valve 30 is in a potential state, the a4 port and the b4 port are not connected; when the fourth solenoid valve 30 is in a potential-free state, the a4 port and the b4 port are connected; the motor gear control system includes a driving motor 31, a reducer 32, a self-rotating gear 33 and a fixed gear 34; the self-rotating gear 33 and the fixed gear 34 are meshed; the driving motor 31 is used to drive the reducer 32 to drive the self-rotating gear 33 to rotate; when the self-rotating gear 33 rotates, the self-rotating gear 33 rotates relatively around the fixed gear 34.

[0022] A wheel-legged robot comprises a body 35, a thigh 36, a shank 37, a wheel 38 and two hydraulic control systems; the hydraulic control system adopts the hydraulic control system of the above-mentioned wheel-legged robot leg joint drive device; one end of the thigh 36 is hinged to the body 35, and the other end of the thigh 36 is hinged to one end of the shank 37; the other end of the shank 37 is provided with a wheel 38; the two hydraulic control systems respectively control the angle between the body 35 and the thigh 36, and the angle between the thigh 36 and the shank 37.

[0023] The beneficial effects of the present invention are:

[0024] The present invention discloses a wheel-leg robot and a leg joint driving device thereof, belonging to the technical field of wheel-leg robots, and including a hydraulic control system; the hydraulic control system includes a hydraulic cylinder, a piston rod, a main oil circuit, a secondary oil circuit, a servo motor and a hydraulic pump; a load-bearing chamber and a non-load-bearing chamber are arranged in the hydraulic cylinder; the piston rod separates the load-bearing chamber and the non-load-bearing chamber; the servo motor is used to drive the hydraulic pump; the non-load-bearing chamber, the main oil circuit, the hydraulic pump, the secondary oil circuit and the load-bearing chamber are connected in sequence; the extension of the piston rod relative to the hydraulic cylinder changes with the change of the hydraulic oil capacity in the load-bearing chamber and the non-load-bearing chamber. The wheel-leg robot and the leg joint driving device of the present invention have no overflow loss, no throttling loss, save system power, and the hydraulic system has high transmission efficiency, high energy utilization, good buffering performance and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of the structure of the hydraulic control system in the passive vibration reduction step of the present invention in the first embodiment;

[0026] Figure 2 is a schematic diagram of the structure of a hydraulic control system in the posture adjustment step of the present invention in the first embodiment;

[0027] Figure 3 It is a structural schematic diagram of a hydraulic control system in an active gait step of the present invention in the first embodiment;

[0028] Figure 4 It is a schematic structural diagram of the active / passive vibration reduction step and the posture adjustment step of the wheel-legged robot of the present invention in the first, second and fourth embodiments;

[0029] Figure 5 It is a schematic structural diagram of the wheel-legged robot of the present invention in the active gait step in embodiments one, two and four;

[0030] Figure 6 This is a schematic diagram of the structure of the hydraulic control system of the present invention in Embodiment 2;

[0031] Figure 7 It is a schematic diagram of the structure of the hydraulic control system of the present invention in Embodiment 3;

[0032] Figure 8 This is a schematic structural diagram of the wheel-legged robot of the present invention in the active vibration reduction step and the posture adjustment step in the third embodiment;

[0033] Fig. 9 This is a schematic diagram of the structure of the wheel-legged robot in the active gait step of the present invention in the third embodiment;

[0034] Fig.10 It is a schematic diagram of the structure of the hydraulic control system of the present invention in the fourth embodiment;

[0035] In the attached figure: 1-hydraulic cylinder, 2-piston rod, 3-first oil circuit, 4-second oil circuit, 5-third oil circuit, 6-fourth oil circuit, 7-servo motor, 8-hydraulic pump, 9-load-bearing chamber, 10-non-load-bearing chamber, 11-first overflow valve, 12-second overflow valve, 13-oil replenishing accumulator, 14-first check valve, 15-second check valve, 16-high-pressure accumulator, 17-fifth oil circuit, 18-sixth oil circuit, 19-seventh oil circuit , 20-eighth oil circuit, 21-second solenoid valve, 22-first solenoid valve, 23-first throttle valve, 24-third solenoid valve, 25-second throttle valve, 26-second high-pressure accumulator, 27-guide rod, 28-guide path, 29-spring, 30-fourth solenoid valve, 31-drive motor, 32-reducer, 33-rotating gear, 34-fixed gear, 35-body, 36-thigh, 37-calf, 38-wheel. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, but the present invention is not limited to the following embodiments.

[0037] Embodiment 1:

[0038] See attached Figures 1 to 5 A leg joint driving device of a wheel-legged robot includes a hydraulic control system; the hydraulic control system includes a hydraulic cylinder 1, a piston rod 2, a main oil circuit, a secondary oil circuit, a servo motor 7 and a hydraulic pump 8; a load-bearing chamber 9 and a non-load-bearing chamber 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates the load-bearing chamber 9 and the non-load-bearing chamber 10; the servo motor 7 is used to drive the hydraulic pump 8; the non-load-bearing chamber 10, the main oil circuit, the hydraulic pump 8, the secondary oil circuit and the load-bearing chamber 9 are connected in sequence; the extension of the piston rod 2 relative to the hydraulic cylinder 1 changes with the change of the hydraulic oil capacity in the load-bearing chamber 9 and the non-load-bearing chamber 10. It can be seen from the above structure that if the circuits formed by the non-load-bearing chamber 10, the main oil circuit, the hydraulic pump 8, the secondary oil circuit and the load-bearing chamber 9 are connected in sequence, the servo motor 7 rotates forward, the hydraulic oil in the load-bearing chamber 9 is sucked into the non-load-bearing chamber 10 by the hydraulic pump 8, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the angle between the car body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; the servo motor 7 rotates reversely, the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, the piston rod 2 is extended relative to the extension of the hydraulic cylinder 1, and the angle between the car body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased. The servo valve control cylinder is eliminated to achieve no throttling loss.

[0039] The hydraulic control system also includes an oil replenishment accumulator 13, a high-pressure accumulator 16, a high-pressure oil circuit and a low-pressure oil circuit; the outlet of the oil replenishment accumulator 13 is connected to the non-load-bearing chamber 10 through the low-pressure oil circuit; the outlet of the high-pressure accumulator 16 is connected to the load-bearing chamber 9 through the high-pressure oil circuit. It can be seen from the above structure that the outlet of the oil replenishment accumulator 13 leads to the non-load-bearing chamber 10 through the low-pressure oil circuit; the outlet of the high-pressure accumulator 16 leads to the load-bearing chamber 9 through the high-pressure oil circuit; when the wheel 38 touches the ground and rotates, it drives the wheel-leg robot to travel; when the wheel-leg robot travels on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 becomes larger, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the hydraulic oil pressure in the load-bearing chamber 9 increases. The hydraulic oil with increased pressure enters the high-pressure accumulator 16 through the high-pressure oil circuit, so that the increase in the hydraulic oil pressure in the load-bearing chamber 9 is buffered. At the same time, the hydraulic oil of the oil replenishment accumulator 13 replenishes oil to the non-load-bearing chamber 10 through the low-pressure oil circuit; When the wheel-leg robot travels on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 becomes smaller, the piston rod 2 extends relative to the extension of the hydraulic cylinder 1, the hydraulic oil pressure in the load-bearing chamber 9 decreases, and the hydraulic oil in the high-pressure accumulator 16 enters the load-bearing chamber 9 through the high-pressure oil circuit to replenish the oil, so that the hydraulic oil pressure reduction in the load-bearing chamber 9 is buffered. At the same time, the hydraulic oil in the non-load-bearing chamber 10 flows to the oil replenishing accumulator 13 through the low-pressure oil circuit; the oil replenishing accumulator 13 and the high-pressure accumulator 16 realize vibration reduction during the driving process of the wheel-leg robot to ensure the stability of the vehicle body, absorb vibration energy, reduce the impact on the wheel-leg robot, and increase the service life of the wheel-leg robot.

[0040] The hydraulic control system also includes a second solenoid valve 21; the low-pressure oil circuit includes a fifth oil circuit 17 and a sixth oil circuit 18; the high-pressure oil circuit includes a seventh oil circuit 19 and an eighth oil circuit 20; the second solenoid valve 21 is a two-position four-way solenoid switch valve; the second solenoid valve 21 includes a2 port, b2 port, c2 port and d2 port; the two ends of the fifth oil circuit 17 are respectively connected to the a2 port and the oil replenishment accumulator 13; the two ends of the sixth oil circuit 18 are respectively connected to the b2 port and the non-load-bearing chamber 10; the two ends of the seventh oil circuit 19 are respectively connected to the c2 port and the high-pressure accumulator 16; the two ends of the eighth oil circuit 20 are respectively connected to the d2 port and the load-bearing chamber 9; when the second solenoid valve 21 is in a de-energized state, except that the a2 port and the b2 port are connected, and the c2 port and the d2 port are connected, the other ports are not connected; when the second solenoid valve 21 is in an energized state, all ports are not connected. It can be seen from the above structure that when the second solenoid valve 21 is in the de-energized state, except that the a2 port and the b2 port are connected, and the c2 port and the d2 port are connected, the other ports are not connected, that is, the a2 port and the c2 port and the d2 port are not connected, and the b2 port and the c2 port and the d2 port are not connected. The outlet of the oil replenishment accumulator 13 is connected to the non-load-bearing chamber 10 through the fifth oil circuit 17 and the sixth oil circuit 18 in sequence; the outlet of the high-pressure accumulator 16 is connected to the load-bearing chamber 9 through the seventh oil circuit 19 and the eighth oil circuit 20 in sequence; the oil replenishment accumulator 13 and the high-pressure accumulator 16 can play a buffering role, and the hydraulic oil pressure of the oil replenishment accumulator 13 changes with the hydraulic oil pressure of the non-load-bearing chamber 10; the hydraulic oil pressure of the high-pressure accumulator 16 changes with the hydraulic oil pressure of the load-bearing chamber 9; when the second solenoid valve 21 is in the energized state, all ports are not connected, and the oil replenishment accumulator 13 and the high-pressure accumulator no longer play a vibration buffering role.

[0041] The hydraulic control system also includes a first solenoid valve 22; the main oil circuit includes a first oil circuit 3 and a second oil circuit 4; the secondary oil circuit includes a third oil circuit 5 and a fourth oil circuit 6; the first solenoid valve 22 is a two-position four-way solenoid switch valve; the first solenoid valve 22 includes a1 port, b1 port, c1 port and d1 port; the two ends of the first oil circuit 3 are respectively connected to a1 port and a non-load-bearing chamber 10; the two ends of the second oil circuit 4 are respectively connected to b1 port and a hydraulic pump 8; the two ends of the third oil circuit 5 are respectively connected to c1 port and a hydraulic pump 8; the two ends of the fourth oil circuit 6 are respectively connected to d1 port and a load-bearing chamber 9; when the first solenoid valve 22 is in a potential-earthing state, except that a1 port and b1 port are connected, and c1 port and d1 port are connected, the other ports are not connected; when the first solenoid valve 22 is in a potential-losing state, all ports are not connected. It can be seen from the above structure that when the first solenoid valve 22 is in the potential-gaining state, except that the a1 port and the b1 port are connected, and the c1 port and the d1 port are connected, the other ports are not connected, that is, the a1 port and the c1 port and the d1 port are not connected, and the b1 port and the c1 port and the d1 port are not connected. The circuit formed by the non-load-bearing chamber 10, the first oil circuit 3, the second oil circuit 4, the hydraulic pump 8, the third oil circuit 5, the fourth oil circuit 6 and the load-bearing chamber 9 is connected, and the hydraulic pump 8 can change the flow direction of the hydraulic oil in the load-bearing chamber 9 and the non-load-bearing chamber 10; when the first solenoid valve 22 is in the potential-losing state, the first oil circuit 3 and the second oil circuit 4 are not connected; the third oil circuit 5 and the fourth oil circuit 6 are not connected; the servo motor 7 and the hydraulic pump 8 are in a non-working state.

[0042] The oil replenishment accumulator 13 is connected to the oil drain port of the hydraulic pump 8; the hydraulic control system also includes a first one-way valve 14 and a second one-way valve 15; the outlet of the oil replenishment accumulator 13 is connected to the inlet of the first one-way valve 14 and the inlet of the second one-way valve 15; the outlet of the first one-way valve 14 is connected to the main oil circuit; the outlet of the second one-way valve 15 is connected to the secondary oil circuit. It can be seen from the above structure that the oil replenishment accumulator 13 is connected to the oil drain port of the hydraulic pump 8, and the oil replenishment accumulator 13 can collect the hydraulic oil leaked from the hydraulic pump 8 to reduce oil consumption; if the hydraulic oil pressure in the load-bearing chamber 9 is too low, the oil replenishment accumulator 13 replenishes oil to the hydraulic pump 8 through the second one-way valve 15 to ensure that the hydraulic pump 8 continuously absorbs hydraulic oil; if the hydraulic oil pressure in the non-load-bearing chamber 10 is too low, the oil replenishment accumulator 13 replenishes oil to the hydraulic pump 8 through the first one-way valve 14 to ensure that the hydraulic pump 8 continuously absorbs hydraulic oil; thereby improving energy utilization and reaction speed.

[0043] The hydraulic control system further includes a first relief valve 11 and a second relief valve 12; the inlet of the first relief valve 11 is connected to the main oil circuit; the outlet of the first relief valve 11 is connected to the secondary oil circuit; the inlet of the second relief valve 12 is connected to the secondary oil circuit; the outlet of the second relief valve 12 is connected to the main oil circuit. As can be seen from the above structure, if the hydraulic oil pressure in the load-bearing chamber 9 is too high, the second relief valve 12 will release the pressure; if the hydraulic oil pressure in the non-load-bearing chamber 10 is too high, the first relief valve 11 will release the pressure; to ensure the safe operation of the hydraulic control system.

[0044] The high-pressure oil circuit is provided with a first throttle valve 23. As can be seen from the above structure, the first throttle valve 23 slows down the speed of the exchange between the hydraulic oil in the bearing chamber 9 and the high-pressure accumulator 16, and enhances the buffering effect of the high-pressure accumulator 16.

[0045] The hydraulic cylinder 1 and the piston rod 2 are combined into a symmetrical double-rod hydraulic cylinder.

[0046] A driving method for a leg joint driving device of a wheel-legged robot, comprising a passive vibration reduction step; the passive vibration reduction step is specifically as follows: when the wheel 38 touches the ground and rotates, the wheel-legged robot is driven to travel; the low-pressure oil circuit is connected, and the outlet of the oil replenishment accumulator 13 is connected through the low-pressure oil circuit and the non-load-bearing chamber 10; the high-pressure oil circuit is connected, and the outlet of the high-pressure accumulator 16 is connected through the high-pressure oil circuit and the load-bearing chamber 9; the hydraulic oil is not exchanged between the load-bearing chamber 9 and the non-load-bearing chamber 10; when the wheel-legged robot travels on flat ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 does not fluctuate, the vehicle body 35 does not vibrate, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 remains unchanged, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 remain unchanged; when the wheel-legged robot travels on uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 becomes larger, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the load The hydraulic oil pressure in cavity 9 increases, and the hydraulic oil with increased pressure enters the high-pressure accumulator 16 through the high-pressure oil circuit, so that the increase in the hydraulic oil pressure in the load-bearing cavity 9 is buffered. At the same time, the hydraulic oil in the oil replenishing accumulator 13 replenishes oil to the non-load-bearing cavity 10 through the low-pressure oil circuit, and the angle between the car body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; when the wheel-legged robot travels on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 decreases, the piston rod 2 is extended relative to the elongation of the hydraulic cylinder 1, the hydraulic oil pressure in the load-bearing cavity 9 is reduced, and the hydraulic oil in the high-pressure accumulator 16 enters the load-bearing cavity 9 through the high-pressure oil circuit to replenish oil, so that the decrease in the hydraulic oil pressure in the load-bearing cavity 9 is buffered. At the same time, the hydraulic oil in the non-load-bearing cavity 10 flows to the oil replenishing accumulator 13 through the low-pressure oil circuit, and the angle between the car body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased.

[0047] It also includes an active gait step; the active gait step is specifically as follows: when the wheel-legged robot encounters an obstacle while driving, the low-pressure oil circuit is disconnected, and the outlet of the oil-making accumulator 13 cannot be connected to the non-load-bearing chamber 10 through the low-pressure oil circuit; the high-pressure oil circuit is disconnected, and the outlet of the high-pressure accumulator 16 cannot be connected to the load-bearing chamber 9 through the high-pressure oil circuit; hydraulic oil is forcibly exchanged between the load-bearing chamber 9 and the non-load-bearing chamber 10; when the wheel-legged robot is in the process of lifting its legs, the hydraulic oil in the load-bearing chamber 9 is sucked into the non-load-bearing chamber 10, the piston rod 2 is shortened relative to the elongation of the hydraulic cylinder 1, and the angle between the body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; when the wheel-legged robot is in the process of lowering its legs, the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, the piston rod 2 is extended relative to the elongation of the hydraulic cylinder 1, and the angle between the body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased.

[0048] It also includes a posture adjustment step; the posture adjustment step is specifically as follows: when the wheel-legged robot needs to adjust the height of the vehicle body 35, the low-pressure oil circuit is connected, and the outlet of the oil-replenishing accumulator 13 is connected through the low-pressure oil circuit and the non-load-bearing chamber 10; the high-pressure oil circuit is connected, and the outlet of the high-pressure accumulator 16 is connected through the high-pressure oil circuit and the load-bearing chamber 9; the hydraulic oil is forcibly exchanged between the load-bearing chamber 9 and the non-load-bearing chamber 10; when the wheel-legged robot needs to increase the height of the vehicle body 35, the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, and the piston rod 2 is extended relative to the extension of the hydraulic cylinder 1 longer, the angle between the body 35 and the thigh 36, as well as the angle between the thigh 36 and the calf 37, both become larger; when the wheel-legged robot needs to lower the height of the body 35, the hydraulic oil in the load-bearing chamber 9 is sucked into the non-load-bearing chamber 10 by the hydraulic pump 8, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the angle between the body 35 and the thigh 36, as well as the angle between the thigh 36 and the calf 37, both become smaller; the hydraulic oil pressure in the oil replenishment accumulator 13 is balanced with the non-load-bearing chamber 10; the hydraulic oil pressure in the high-pressure accumulator 16 is balanced with the load-bearing chamber 9. As can be seen from the above structure, the present invention has multiple working modes. In the posture adjustment step, the height of the vehicle body 35 can be adjusted according to the road conditions to be driven; in the passive vibration reduction step, the driving vibration reduction on uphill and downhill roads can be effectively achieved to ensure the stability of the wheel-legged robot during driving; in the active gait step, the leg can be quickly lifted and lowered, obstacles can be crossed, and the stability of the vehicle body 35 can be ensured; the oil replenishment function of the oil replenishment accumulator 13 and the safety protection function of the first overflow valve 11 and the second overflow valve 12 make the wheel-legged robot run safer and more reliable, and increase its service life. The servo valve control cylinder is eliminated to achieve no throttling loss, and at the same time, a buffer device with absorption force is provided to greatly improve the efficiency of joint drive, improve the effective energy utilization rate of the robot, and extend the life of the robot.

[0049] Embodiment 2:

[0050] See attached Figures 4 to 6 A leg joint driving device of a wheel-legged robot includes a hydraulic control system; the hydraulic control system includes a hydraulic cylinder 1, a piston rod 2, a main oil circuit, a secondary oil circuit, a servo motor 7 and a hydraulic pump 8; a load-bearing chamber 9 and a non-load-bearing chamber 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates the load-bearing chamber 9 and the non-load-bearing chamber 10; the servo motor 7 is used to drive the hydraulic pump 8; the non-load-bearing chamber 10, the main oil circuit, the hydraulic pump 8, the secondary oil circuit and the load-bearing chamber 9 are connected in sequence; the extension of the piston rod 2 relative to the hydraulic cylinder 1 changes with the change of the hydraulic oil capacity in the load-bearing chamber 9 and the non-load-bearing chamber 10. It can be seen from the above structure that if the circuits formed by the non-load-bearing chamber 10, the main oil circuit, the hydraulic pump 8, the secondary oil circuit and the load-bearing chamber 9 are connected in sequence, the servo motor 7 rotates forward, the hydraulic oil in the load-bearing chamber 9 is sucked into the non-load-bearing chamber 10 by the hydraulic pump 8, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the angle between the car body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; the servo motor 7 rotates reversely, the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, the piston rod 2 is extended relative to the extension of the hydraulic cylinder 1, and the angle between the car body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased. The servo valve control cylinder is eliminated to achieve no throttling loss.

[0051] The hydraulic control system further includes a second high-pressure accumulator 26 ; the second high-pressure accumulator 26 is connected to the bearing chamber 9 through an oil circuit. It can be seen from the above structure that when the wheel 38 touches the ground and rotates, it drives the wheel-leg robot to travel; when the wheel-leg robot travels on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 becomes larger, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the hydraulic oil pressure in the load-bearing chamber 9 increases, and the hydraulic oil with increased pressure enters the second high-pressure accumulator 26 through the oil circuit, so that the increase in the hydraulic oil pressure in the load-bearing chamber 9 is buffered; when the wheel-leg robot travels on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 becomes smaller, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the hydraulic oil pressure in the load-bearing chamber 9 is reduced, and the hydraulic oil in the second high-pressure accumulator 26 enters the load-bearing chamber 9 through the oil circuit to replenish oil, so that the decrease in the hydraulic oil pressure in the load-bearing chamber 9 is buffered; the second high-pressure accumulator 26 realizes vibration reduction during the driving process of the wheel-leg robot to ensure the stability of the vehicle body, absorbs vibration energy, reduces the impact on the wheel-leg robot, and increases the service life of the wheel-leg robot.

[0052] The hydraulic control system also includes a third solenoid valve 24; the main oil circuit includes the first oil circuit 3 and the second oil circuit 4; the secondary oil circuit includes the third oil circuit 5 and the fourth oil circuit 6; the third solenoid valve 24 is a two-position four-way solenoid switch valve; the third solenoid valve 24 includes port a3, port b3, port c3 and port d3; the two ends of the first oil circuit 3 are connected to port a3 and a non-load-bearing chamber 10 respectively; the two ends of the second oil circuit 4 are connected to port b3 and a hydraulic pump 8 respectively; the two ends of the third oil circuit 5 are connected to port c3 and a hydraulic pump 8 respectively; the two ends of the fourth oil circuit 6 are connected to port d3 and a load-bearing chamber 9 respectively; when the third solenoid valve 24 is in a potential-earthing state, except that port a3 and port b3 are connected, and port c3 and port d3 are connected, the other ports are not connected; when the third solenoid valve 24 is in a potential-losing state, except that port a3 and port d3 are connected, the other ports are not connected. It can be seen from the above structure that when the third solenoid valve 24 is in the state of gaining potential, except that the a3 port and the b3 port are connected, and the c3 port and the d3 port are connected, the other ports are not connected, that is, the a3 port and the c3 port and the d3 port are not connected, and the b3 port and the c3 port and the d3 port are not connected. The circuit formed by the non-load-bearing chamber 10, the first oil circuit 3, the second oil circuit 4, the hydraulic pump 8, the third oil circuit 5, the fourth oil circuit 6 and the load-bearing chamber 9 is already connected, and the hydraulic pump 8 can change the flow direction of the hydraulic oil in the load-bearing chamber 9 and the non-load-bearing chamber 10; when the third solenoid valve 24 is in the state of losing potential, except that the a3 port and the d3 port are connected, the other ports are not connected, and the load-bearing chamber 9 is connected to the non-load-bearing chamber 10 through the first oil circuit 3, the fourth oil circuit 6; the high-pressure hydraulic oil in the load-bearing chamber 9 can flow to the non-load-bearing chamber 10, so that the vehicle body 35 descends, and when the power is lost, the wheel-legged robot becomes smaller, which is convenient for transportation.

[0053] When the third solenoid valve 24 is in a de-energized state, a second throttle valve 25 is provided on the path connecting the a3 port and the d3 port. As can be seen from the above structure, the second throttle valve 25 slows down the speed of the hydraulic oil in the load-bearing chamber 9 and the non-load-bearing chamber 10. The load-bearing chamber 9 is connected to the non-load-bearing chamber 10 through the first oil path 3 and the fourth oil path 6; the high-pressure hydraulic oil in the load-bearing chamber 9 flows to the non-load-bearing chamber 10 and is throttled by the second throttle valve 25, so that the vehicle body 35 slowly descends.

[0054] The hydraulic control system further includes a first relief valve 11 and a second relief valve 12; the inlet of the first relief valve 11 is connected to the main oil circuit; the outlet of the first relief valve 11 is connected to the secondary oil circuit; the inlet of the second relief valve 12 is connected to the secondary oil circuit; the outlet of the second relief valve 12 is connected to the main oil circuit. As can be seen from the above structure, if the hydraulic oil pressure in the load-bearing chamber 9 is too high, the second relief valve 12 will release the pressure; if the hydraulic oil pressure in the non-load-bearing chamber 10 is too high, the first relief valve 11 will release the pressure; to ensure the safe operation of the hydraulic control system.

[0055] The hydraulic cylinder 1 is an asymmetric hydraulic cylinder.

[0056] The hydraulic control system also includes a controller and a force sensor; the force sensor, the third solenoid valve 24, and the servo motor 7 are electrically connected to the controller respectively; the force sensor is used to monitor the load signal of the piston rod 2 and transmit the load signal to the controller; the controller is used to control the switch position of the third solenoid valve 24 and the speed and direction of the servo motor 7. It can be seen from the above structure that when the wheel-legged robot travels on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 increases, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the hydraulic oil pressure in the bearing chamber 9 increases, and the hydraulic oil with increased pressure enters the second high-pressure accumulator 26 through the oil circuit, so that the increase in the hydraulic oil pressure in the bearing chamber 9 is buffered. At the same time, the force sensor monitors the load signal of the increased load force of the piston rod 2 and transmits the load signal to the controller; the controller controls the servo motor 7 to rotate forward, and the hydraulic oil in the bearing chamber 9 is sucked to the non-bearing chamber 10 by the hydraulic pump 8, so that the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly shortened, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both becomes smaller; when the wheel-leg robot travels on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 becomes smaller, the piston rod 2 extends relative to the elongation of the hydraulic cylinder 1, the hydraulic oil pressure in the load-bearing chamber 9 decreases, and the hydraulic oil in the second high-pressure accumulator 26 enters the load-bearing chamber 9 through the oil circuit to replenish oil, so that the hydraulic oil pressure reduction in the load-bearing chamber 9 is buffered. At the same time, the force sensor detects the load signal of the reduced load force of the piston rod 2 and transmits the load signal to the controller; the controller controls the servo motor 7 to reverse, and the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, so that the piston rod 2 extends rapidly relative to the elongation of the hydraulic cylinder 1, and the angle between the body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased.

[0057] A driving method for a leg joint driving device of a wheel-legged robot, comprising an active vibration reduction step; the active vibration reduction step is specifically as follows: when the wheel 38 touches the ground and rotates, the wheel-legged robot is driven to travel; when the wheel-legged robot travels on flat ground, the hydraulic oil is temporarily not forcibly exchanged between the load-bearing chamber 9 and the non-load-bearing chamber 10; the load force borne by the hydraulic cylinder 1 and the piston rod 2 does not fluctuate, the vehicle body 35 does not vibrate, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 remains unchanged, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 remain unchanged; when the wheel-legged robot travels on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 increases, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 decreases, the hydraulic oil pressure in the load-bearing chamber 9 increases, and the hydraulic oil with increased pressure enters the second high-pressure accumulator 26 through the oil circuit, so that the increase in the hydraulic oil pressure in the load-bearing chamber 9 is buffered, and at the same time, the load-bearing chamber 9 and the non-load-bearing chamber 10 The hydraulic oil is forced to be exchanged between the load-bearing chamber 9, and the hydraulic oil in the load-bearing chamber 9 is sucked into the non-load-bearing chamber 10 by the hydraulic pump 8, so that the extension of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly shortened, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; when the wheel-legged robot travels on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the hydraulic oil pressure in the load-bearing chamber 9 is reduced, and the hydraulic oil in the second high-pressure accumulator 26 enters the load-bearing chamber 9 through the oil circuit to replenish the oil, so that the hydraulic oil pressure reduction in the load-bearing chamber 9 is buffered. At the same time, the hydraulic oil is forced to be exchanged between the load-bearing chamber 9 and the non-load-bearing chamber 10, and the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, so that the extension of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly extended, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased.

[0058] It also includes an active gait step; the active gait step is specifically as follows: when the wheel-legged robot encounters an obstacle while driving, the hydraulic oil is forcibly exchanged between the load-bearing cavity 9 and the non-load-bearing cavity 10; when the wheel-legged robot is in the process of lifting its legs, the hydraulic oil in the load-bearing cavity 9 is sucked into the non-load-bearing cavity 10 by the hydraulic pump 8, so that the piston rod 2 is rapidly shortened relative to the elongation of the hydraulic cylinder 1, and the angle between the body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; when the wheel-legged robot is in the process of lowering its legs, the hydraulic oil in the non-load-bearing cavity 10 is sucked into the load-bearing cavity 9 by the hydraulic pump 8, so that the piston rod 2 is rapidly extended relative to the elongation of the hydraulic cylinder 1, and the angle between the body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased.

[0059] It also includes a posture adjustment step; the posture adjustment step is specifically as follows: when the wheel-legged robot needs to adjust the height of the vehicle body 35, the hydraulic oil is forcibly exchanged between the load-bearing cavity 9 and the non-load-bearing cavity 10; when the wheel-legged robot needs to increase the height of the vehicle body 35, the hydraulic oil in the non-load-bearing cavity 10 is sucked into the load-bearing cavity 9 by the hydraulic pump 8, and the piston rod 2 is extended relative to the elongation of the hydraulic cylinder 1, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased; when the wheel-legged robot needs to lower the height of the vehicle body 35, the hydraulic oil in the load-bearing cavity 9 is sucked into the non-load-bearing cavity 10 by the hydraulic pump 8, and the piston rod 2 is shortened relative to the elongation of the hydraulic cylinder 1, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced.

[0060] It also includes a power-off step; the power-off step is specifically as follows: when the wheel-legged robot loses power, the hydraulic oil is freely exchanged between the load-bearing chamber 9 and the non-load-bearing chamber 10; the high-pressure hydraulic oil in the load-bearing chamber 9 flows to the non-load-bearing chamber 10, causing the vehicle body 35 to slowly descend; at the same time, the second high-pressure accumulator 26 performs vibration reduction by exchanging hydraulic oil with the load-bearing chamber 9. It can be seen from the above structure that the present invention has multiple working modes. In the posture adjustment step, the height of the vehicle body 35 can be adjusted according to the road conditions to be driven; in the active vibration reduction step, the driving vibration reduction on uphill and downhill roads can be effectively achieved to ensure the stability of the wheel-legged robot during driving; in the active gait step, the leg can be quickly lifted and lowered, obstacles can be crossed, and the stability of the vehicle body 35 can be ensured; the buffering function of the second high-pressure accumulator 26 and the safety protection function of the first overflow valve 11 and the second overflow valve 12 make the wheel-legged robot run safer and more reliable, and increase its service life. The servo valve controlled cylinder is eliminated to achieve zero throttling loss. At the same time, a buffer device with absorbing force is provided to greatly improve the efficiency of the joint driver, improve the effective energy utilization rate of the robot, and extend the life of the robot joint driver.

[0061] Embodiment three:

[0062] See attached Figures 7 to 9A leg joint driving device of a wheel-legged robot includes a hydraulic control system; the hydraulic control system includes a hydraulic cylinder 1, a piston rod 2, a main oil circuit, a secondary oil circuit, a servo motor 7 and a hydraulic pump 8; a load-bearing chamber 9 and a non-load-bearing chamber 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates the load-bearing chamber 9 and the non-load-bearing chamber 10; the servo motor 7 is used to drive the hydraulic pump 8; the non-load-bearing chamber 10, the main oil circuit, the hydraulic pump 8, the secondary oil circuit and the load-bearing chamber 9 are connected in sequence; the extension of the piston rod 2 relative to the hydraulic cylinder 1 changes with the change of the hydraulic oil capacity in the load-bearing chamber 9 and the non-load-bearing chamber 10. It can be seen from the above structure that if the circuits formed by the non-load-bearing chamber 10, the main oil circuit, the hydraulic pump 8, the secondary oil circuit and the load-bearing chamber 9 are connected in sequence, the servo motor 7 rotates forward, the hydraulic oil in the load-bearing chamber 9 is sucked into the non-load-bearing chamber 10 by the hydraulic pump 8, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the angle between the car body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; the servo motor 7 rotates reversely, the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, the piston rod 2 is extended relative to the extension of the hydraulic cylinder 1, and the angle between the car body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased. The servo valve control cylinder is eliminated to achieve no throttling loss.

[0063] The hydraulic control system also includes a motor gear control system; one hydraulic control system controls the angle between the vehicle body 35 and the thigh 36 by controlling the extension of the piston rod 2 relative to the hydraulic cylinder 1 or through the motor gear control system; the other hydraulic control system controls the angle between the thigh 36 and the calf 37 by controlling the extension of the piston rod 2 relative to the hydraulic cylinder 1 or through the motor gear control system. It can be seen from the above structure that the angle between the vehicle body 35 and the thigh 36 can be controlled by the motor gear control system. The motor gear control system uses a motor and a gear drive assembly to drive the relative rotation between the vehicle body 35 and the thigh 36. When the vehicle body 35 and the thigh 36 are subjected to a large load, the hydraulic cylinder 1 and the piston rod 2 are selected to change the angle between the vehicle body 35 and the thigh 36. When the vehicle body 35 and the thigh 36 are subjected to a small load or no load, the motor gear control system is selected to change the angle between the vehicle body 35 and the thigh 36. This selectable driving mode saves system power, has high transmission efficiency, and high energy utilization rate; in the hydraulic control system corresponding to the thigh 36 and the calf 37, the two ends of the hydraulic cylinder 1 and the piston rod 2 matching assembly are respectively hinged to the thigh 36 and the calf 37, so that the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the angle between the thigh 36 and the calf 37 becomes smaller, and the piston rod 2 is extended relative to the elongation of the hydraulic cylinder 1, and the angle between the thigh 36 and the calf 37 becomes The angle between the thigh 36 and the calf 37 remains unchanged; the angle between the thigh 36 and the calf 37 can also be controlled by a motor gear control system. The motor gear control system uses a motor and a gear drive assembly to drive the relative rotation between the thigh 36 and the calf 37. When a large load is borne between the thigh 36 and the calf 37, the hydraulic cylinder 1 and the piston rod 2 are selected to change the angle between the thigh 36 and the calf 37. When a small load or no load is borne between the thigh 36 and the calf 37, the motor gear control system is selected to change the angle between the thigh 36 and the calf 37. This selectable drive mode saves system power, has high transmission efficiency, and high energy utilization rate; in this way, both hydraulic control systems have two drive modes to control the angle between the vehicle body 35 and the thigh 36, and the angle between the thigh 36 and the calf 37, so that the wheel 38 moves forward, backward, upward, and downward relative to the vehicle body 35 for adjustment.The hydraulic cylinder 1 is provided with a load-bearing chamber 9 and a non-load-bearing chamber 10; the piston rod 2 separates the load-bearing chamber 9 and the non-load-bearing chamber 10; the extension of the piston rod 2 relative to the hydraulic cylinder 1 changes with the change of the hydraulic oil capacity in the load-bearing chamber 9 and the non-load-bearing chamber 10; when the hydraulic oil capacity of the load-bearing chamber 9 increases and the hydraulic oil capacity of the non-load-bearing chamber 10 decreases, the extension of the piston rod 2 relative to the hydraulic cylinder 1 increases, and when the hydraulic oil capacity of the load-bearing chamber 9 decreases and the hydraulic oil capacity of the non-load-bearing chamber 10 increases, the extension of the piston rod 2 relative to the hydraulic cylinder 1 decreases; when the hydraulic oil capacity of the load-bearing chamber 9 and the non-load-bearing chamber 10 remains unchanged, the extension of the piston rod 2 relative to the hydraulic cylinder 1 remains unchanged. The dual-drive structure of the present invention selects a suitable drive mode from a hydraulic actuator with a high power density ratio and an electric transmission to drive the joint according to the working characteristics of the wheel-leg robot, so as to achieve a higher spatial trajectory tracking accuracy and improve the efficiency of the joint driver, thereby improving the effective energy utilization rate of the robot.

[0064] The hydraulic control system also includes a fourth solenoid valve 30; the main oil circuit includes the first oil circuit 3 and the second oil circuit 4; the secondary oil circuit includes the third oil circuit 5 and the fourth oil circuit 6; the fourth solenoid valve 30 is a two-position two-way solenoid switch valve; the fourth solenoid valve 30 includes a4 port and b4 port; the non-load-bearing chamber 10, the first oil circuit 3, the second oil circuit 4, the hydraulic pump 8, the third oil circuit 5, the fourth oil circuit 6 and the load-bearing chamber 9 are connected in sequence; the first oil circuit 3 and the second oil circuit 4 are connected to the a4 port in common; the third oil circuit 5 and the fourth oil circuit 6 are connected to the b4 port in common; when the fourth solenoid valve 30 is in the potential-earthing state, the a4 port and the b4 port are not conducting; when the fourth solenoid valve 30 is in the potential-losing state, the a4 port and the b4 port are conducting. It can be seen from the above structure that the fourth solenoid valve 30 is in a state of gaining potential, and the a4 port and the b4 port are not conducting; the circuit formed by the non-load-bearing chamber 10, the first oil circuit 3, the second oil circuit 4, the hydraulic pump 8, the third oil circuit 5, the fourth oil circuit 6 and the load-bearing chamber 9 is connected; the hydraulic pump 8 can change the flow direction of the hydraulic oil in the load-bearing chamber 9 and the non-load-bearing chamber 10; when the wheel-leg robot loses power, the fourth solenoid valve 30 is in a state of losing potential, and the a4 port and the b4 port are conducting; the non-load-bearing chamber 10 is connected to the load-bearing chamber 9 through the first oil circuit 3, the fourth oil circuit 6 and the load-bearing chamber 9; the servo motor 7 and the hydraulic pump 8 are in a non-working state; when power is lost, the high-pressure hydraulic oil in the load-bearing chamber 9 flows to the non-load-bearing chamber 10, causing the vehicle body 35 to descend, and the wheel-legged robot becomes smaller for easy transportation; when using the motor gear control system, the high-pressure hydraulic oil in the load-bearing chamber 9 flows to the non-load-bearing chamber 10, which facilitates effective adjustment of the electric drive.

[0065] The motor gear control system includes a driving motor 31, a speed reducer 32, a self-rotating gear 33 and a fixed gear 34; the self-rotating gear 33 is meshed with the fixed gear 34; the driving motor 31 is used to drive the speed reducer 32 to drive the self-rotating gear 33 to rotate; when the self-rotating gear 33 rotates, the self-rotating gear 33 rotates relatively around the fixed gear 34. It can be seen from the above structure that in the motor gear control system of the hydraulic control system corresponding to the vehicle body 35 and the thigh 36, the fixed gear 34 is fixed to the hinge shaft between the vehicle body 35 and the thigh 36, the hinge shaft and the vehicle body 35 are fixed, the self-rotating gear 33 is rotatably arranged at one end of the thigh 36 and meshed with the fixed gear 34, the speed reducer 32 is fixed on the thigh 36, the output shaft of the speed reducer 32 and the self-rotating gear 33 are fixed, the driving motor 31 is used to drive the speed reducer 32 to drive the self-rotating gear 33 to rotate, the self-rotating gear 33 rotates relatively around the fixed gear 34, the thigh 36 swings relative to the vehicle body 35, and the space between the vehicle body 35 and the thigh 36 The angle changes; in the motor gear control system of the hydraulic control system corresponding to the thigh 36 and the calf 37, the fixed gear 34 is fixed to the hinge shaft between the thigh 36 and the calf 37, the hinge shaft and the calf 37 are fixed, the autorotation gear 33 is rotatably arranged at the other end of the thigh 36 and meshes with the fixed gear 34, the reducer 32 is fixed on the thigh 36, the output shaft of the reducer 32 and the autorotation gear 33 are fixed, and the drive motor 31 is used to drive the reducer 32 to drive the autorotation gear 33 to rotate, the autorotation gear 33 rotates relatively around the fixed gear 34, the calf 37 swings relative to the thigh 36, and the angle between the thigh 36 and the calf 37 changes.

[0066] The hydraulic control system further includes a first relief valve 11 and a second relief valve 12; the inlet of the first relief valve 11 is connected to the main oil circuit; the outlet of the first relief valve 11 is connected to the secondary oil circuit; the inlet of the second relief valve 12 is connected to the secondary oil circuit; the outlet of the second relief valve 12 is connected to the main oil circuit. As can be seen from the above structure, if the hydraulic oil pressure in the load-bearing chamber 9 is too high, the second relief valve 12 will release the pressure; if the hydraulic oil pressure in the non-load-bearing chamber 10 is too high, the first relief valve 11 will release the pressure; to ensure the safe operation of the hydraulic control system.

[0067] The hydraulic control system further includes an oil replenishment accumulator 13, which is connected to the oil drain port of the hydraulic pump 8. As can be seen from the above structure, the oil replenishment accumulator 13 is connected to the oil drain port of the hydraulic pump 8, and the oil replenishment accumulator 13 can collect the hydraulic oil leaked from the hydraulic pump 8 to reduce oil consumption.

[0068] The hydraulic control system further includes a first one-way valve 14 and a second one-way valve 15; the outlet of the oil replenishment accumulator 13 is connected to the inlet of the first one-way valve 14 and the inlet of the second one-way valve 15; the outlet of the first one-way valve 14 is connected to the main oil circuit; the outlet of the second one-way valve 15 is connected to the secondary oil circuit. It can be seen from the above structure that if the hydraulic oil pressure in the load-bearing chamber 9 is too low, the oil replenishment accumulator 13 replenishes oil to the hydraulic pump 8 through the second one-way valve 15 to ensure that the hydraulic pump 8 continuously inhales hydraulic oil; if the hydraulic oil pressure in the non-load-bearing chamber 10 is too low, the oil replenishment accumulator 13 replenishes oil to the hydraulic pump 8 through the first one-way valve 14 to ensure that the hydraulic pump 8 continuously inhales hydraulic oil, thereby improving energy utilization and reaction speed.

[0069] The hydraulic control system also includes a second controller and a second force sensor; the second force sensor, the fourth solenoid valve 30, and the servo motor 7 are electrically connected to the second controller respectively; the second force sensor is used to monitor the load signal of the piston rod 2 and transmit the load signal to the second controller; the second controller is used to control the switch position of the fourth solenoid valve 30, the drive motor 31 and the speed and direction of the servo motor 7. It can be seen from the above structure that when the wheel-legged robot travels on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 increases, the second force sensor detects the load signal of the increased load force of the piston rod 2, and transmits the load signal to the second controller; the second controller controls the servo motor 7 to rotate forward, and the hydraulic oil in the load-bearing chamber 9 is sucked to the non-load-bearing chamber 10 by the hydraulic pump 8, so that the extension of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly shortened, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; when the wheel-legged robot travels on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 decreases, the second force sensor detects the load signal of the reduced load force of the piston rod 2, and transmits the load signal to the second controller; the second controller controls the servo motor 7 to rotate reversely, and the hydraulic oil in the non-load-bearing chamber 10 is sucked to the load-bearing chamber 9 by the hydraulic pump 8, so that the piston rod 2 is rapidly extended relative to the extension of the hydraulic cylinder 1, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased.

[0070] A driving method for a leg joint driving device of a wheel-legged robot includes an active vibration reduction step; the active vibration reduction step is specifically as follows: when the wheel 38 touches the ground and rotates, the wheel-legged robot is driven to travel; when the wheel-legged robot travels on a flat ground, the hydraulic oil is temporarily not forcibly exchanged between the load-bearing cavity 9 and the non-load-bearing cavity 10; the load force borne by the hydraulic cylinder 1 and the piston rod 2 does not fluctuate, the vehicle body 35 does not vibrate, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 remains unchanged, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 remain unchanged; when the wheel-legged robot travels on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 becomes larger, and the load-bearing cavity 9 and the non-load-bearing cavity 1 0, the hydraulic oil is forced to exchange between the load-bearing chamber 9 and the non-load-bearing chamber 10, the hydraulic oil in the non-load-bearing chamber 10 is sucked by the hydraulic pump 8 to the load-bearing chamber 9, so that the extension of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly shortened, and the angle between the vehicle body 35 and the thigh 36, as well as the angle between the thigh 36 and the calf 37 are both reduced; when the wheel-legged robot travels on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the hydraulic oil is forced to exchange between the load-bearing chamber 9 and the non-load-bearing chamber 10, the hydraulic oil in the non-load-bearing chamber 10 is sucked by the hydraulic pump 8 to the load-bearing chamber 9, so that the extension of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly extended, and the angle between the vehicle body 35 and the thigh 36, as well as the angle between the thigh 36 and the calf 37 are both increased.

[0071] It also includes an active gait step; the active gait step is specifically as follows: when the wheel-legged robot encounters an obstacle while traveling, hydraulic oil is freely exchanged between the load-bearing cavity 9 and the non-load-bearing cavity 10; when the wheel-legged robot is in the process of lifting its legs, the motor gear control systems corresponding to the two hydraulic control systems respectively reduce the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37; when the wheel-legged robot is in the process of lowering its legs, the motor gear control systems corresponding to the two hydraulic control systems respectively increase the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37.

[0072] It also includes a posture adjustment step; the posture adjustment step is specifically as follows: when the wheel-legged robot needs to adjust the height of the vehicle body 35, the hydraulic oil is forcibly exchanged between the load-bearing cavity 9 and the non-load-bearing cavity 10; when the wheel-legged robot needs to increase the height of the vehicle body 35, the hydraulic oil in the non-load-bearing cavity 10 is sucked into the load-bearing cavity 9 by the hydraulic pump 8, and the piston rod 2 is extended relative to the elongation of the hydraulic cylinder 1, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased; when the wheel-legged robot needs to lower the height of the vehicle body 35, the hydraulic oil in the load-bearing cavity 9 is sucked into the non-load-bearing cavity 10 by the hydraulic pump 8, and the piston rod 2 is shortened relative to the elongation of the hydraulic cylinder 1, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced.

[0073] It also includes a power-off step; the power-off step is specifically as follows: when the wheel-legged robot loses power, the hydraulic oil is freely exchanged between the load-bearing chamber 9 and the non-load-bearing chamber 10; the high-pressure hydraulic oil in the load-bearing chamber 9 flows to the non-load-bearing chamber 10, causing the vehicle body 35 to descend. As can be seen from the above structure, the present invention has multiple working modes. In the posture adjustment step, the height of the vehicle body 35 can be adjusted according to the road conditions to be driven; in the active vibration reduction step, the driving vibration reduction on uphill and downhill roads can be effectively achieved to ensure the stability of the wheel-legged robot during driving; in the active gait step, the leg can be quickly lifted and lowered, obstacles can be crossed, and the stability of the vehicle body 35 can be ensured; the oil replenishment function of the oil replenishment accumulator 13 and the safety protection function of the first overflow valve 11 and the second overflow valve 12 make the wheel-legged robot run safer and more reliable, and increase its service life. The servo valve control cylinder is cancelled to achieve no throttling loss. The dual-drive structure of the present invention selects a suitable drive mode from the hydraulic actuator and electric transmission with a high power density ratio to drive the joints according to the working characteristics of the wheel-legged robot, thereby achieving higher spatial trajectory tracking accuracy and improving the efficiency of the joint driver, thereby improving the effective energy utilization of the robot.

[0074] Embodiment 4:

[0075] See attached Figure 4 , 5 , 10. A leg joint driving device of a wheel-legged robot, comprising a hydraulic control system; the hydraulic control system comprises a hydraulic cylinder 1, a piston rod 2, a main oil circuit, a secondary oil circuit, a servo motor 7 and a hydraulic pump 8; a load-bearing chamber 9 and a non-load-bearing chamber 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates the load-bearing chamber 9 and the non-load-bearing chamber 10; the servo motor 7 is used to drive the hydraulic pump 8; the non-load-bearing chamber 10, the main oil circuit, the hydraulic pump 8, the secondary oil circuit and the load-bearing chamber 9 are connected in sequence; the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 changes with the change of the hydraulic oil capacity in the load-bearing chamber 9 and the non-load-bearing chamber 10. It can be seen from the above structure that if the circuits formed by the non-load-bearing chamber 10, the main oil circuit, the hydraulic pump 8, the secondary oil circuit and the load-bearing chamber 9 are connected in sequence, the servo motor 7 rotates forward, the hydraulic oil in the load-bearing chamber 9 is sucked into the non-load-bearing chamber 10 by the hydraulic pump 8, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the angle between the car body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; the servo motor 7 rotates reversely, the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, the piston rod 2 is extended relative to the extension of the hydraulic cylinder 1, and the angle between the car body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased. The servo valve control cylinder is eliminated to achieve no throttling loss.

[0076] The hydraulic cylinder 1 is provided with a load-bearing chamber 9 , a non-load-bearing chamber 10 and a spring 29 ; the spring 29 is used to make the rod portion of the piston rod 2 tend to extend out of the hydraulic cylinder 1 . It can be seen from the above structure that when the wheel 38 touches the ground and rotates, it drives the wheel-leg robot to travel; when the wheel-leg robot travels on flat ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 does not fluctuate, the body 35 does not vibrate, and the spring 29 stably bears the pressure of the piston rod 2, reducing the pressure borne by the hydraulic oil in the bearing chamber 9; when the wheel-leg robot travels on uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 becomes larger, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the hydraulic oil pressure in the bearing chamber 9 increases, and the compression of the spring 29 increases, so that the increase in the hydraulic oil pressure in the bearing chamber 9 is buffered; when the wheel-leg robot travels on downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 becomes smaller, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the hydraulic oil pressure in the bearing chamber 9 is reduced, the compression of the spring 29 is reduced, and the rod part of the auxiliary piston rod 2 extends out of the hydraulic cylinder 1; the spring 29 realizes vibration reduction during the travel of the wheel-leg robot to ensure the stability of the body, absorbs vibration energy, reduces the impact on the wheel-leg robot, and improves the service life of the wheel-leg robot. The spring is cleverly used to reduce the input power requirement of the joint drive device, reduce the demand for input energy, greatly improve the efficiency of the joint drive, improve the effective energy utilization of the robot, and extend the cruising time of the robot.

[0077] A guide rod 27 is provided in the hydraulic cylinder 1; the piston rod 2 is hollow inside and is sleeved on the guide rod 27; the load-bearing chamber 9 is located at the top of the guide rod 27 and is surrounded by the rod portion of the piston rod 2; a guide passage 28 is provided in the guide rod 27; the guide passage 28 connects the load-bearing chamber 9 and the secondary oil circuit; a spring 29 is sleeved on the guide rod 27; the non-load-bearing chamber 10 is located between the rod portion of the piston rod 2 and the hydraulic cylinder 1. As can be seen from the above structure, the piston rod 2 is hollow inside and is covered on the guide rod 27. The guide rod 27 guides the extension and shortening movement of the piston rod 2 relative to the hydraulic cylinder 1. A guide passage 28 is provided in the guide rod 27. The guide passage 28 connects the load-bearing chamber 9 and the secondary oil circuit. When the piston rod 2 is shortened relative to the elongation of the hydraulic cylinder 1, the hydraulic oil pressure in the load-bearing chamber 9 increases, the plug pressure of the piston rod 2 borne by the spring 29 increases, the compression of the spring 29 increases, and the hydraulic oil in the load-bearing chamber 9 flows to the secondary oil circuit through the guide passage 28 and is sucked into the non-load-bearing chamber 10 by the hydraulic pump 8. When the piston rod 2 is extended relative to the elongation of the hydraulic cylinder 1, the hydraulic oil pressure in the load-bearing chamber 9 decreases, the plug pressure of the piston rod 2 borne by the spring 29 decreases, and the compression of the spring 29 decreases, the rod portion of the auxiliary piston rod 2 extends out of the hydraulic cylinder 1, and the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, so that the piston rod 2 is rapidly extended relative to the elongation of the hydraulic cylinder 1. A spring 29 is disposed on the guide rod 27 so that the spring 29 is always compressed between the plug portion of the piston rod 2 and the bottom of the hydraulic cylinder 1 .

[0078] The hydraulic control system also includes a third solenoid valve 24; the main oil circuit includes the first oil circuit 3 and the second oil circuit 4; the secondary oil circuit includes the third oil circuit 5 and the fourth oil circuit 6; the third solenoid valve 24 is a two-position four-way solenoid switch valve; the third solenoid valve 24 includes port a3, port b3, port c3 and port d3; the two ends of the first oil circuit 3 are connected to port a3 and the non-load-bearing chamber 10 respectively; the two ends of the second oil circuit 4 are connected to port b3 and the hydraulic pump 8 respectively; the two ends of the third oil circuit 5 are connected to port c3 and the hydraulic pump 8 respectively; the two ends of the fourth oil circuit 6 are connected to port d3 and the guide path 28 respectively; when the third solenoid valve 24 is in a potential-gaining state, except that port a3 and port b3 are connected, and port c3 and port d3 are connected, the other ports are not connected; when the third solenoid valve 24 is in a potential-losing state, except that port a3 and port d3 are connected, the other ports are not connected. It can be seen from the above structure that when the third solenoid valve 24 is in the state of gaining potential, except that the a3 port and the b3 port are connected, and the c3 port and the d3 port are connected, the other ports are not connected, that is, the a3 port and the c3 port and the d3 port are not connected, and the b3 port and the c3 port and the d3 port are not connected. The circuit formed by the non-load-bearing chamber 10, the first oil circuit 3, the second oil circuit 4, the hydraulic pump 8, the third oil circuit 5, the fourth oil circuit 6 and the load-bearing chamber 9 is already connected, and the hydraulic pump 8 can change the flow direction of the hydraulic oil in the load-bearing chamber 9 and the non-load-bearing chamber 10; when the third solenoid valve 24 is in the state of losing potential, except that the a3 port and the d3 port are connected, the other ports are not connected, and the load-bearing chamber 9 is connected to the non-load-bearing chamber 10 through the first oil circuit 3, the fourth oil circuit 6; the high-pressure hydraulic oil in the load-bearing chamber 9 can flow to the non-load-bearing chamber 10, so that the vehicle body 35 descends, and when the power is lost, the wheel-legged robot becomes smaller, which is convenient for transportation.

[0079] When the third solenoid valve 24 is in a de-energized state, a second throttle valve 25 is provided on the path connecting the a3 port and the d3 port. As can be seen from the above structure, the second throttle valve 25 slows down the speed of the hydraulic oil in the load-bearing chamber 9 and the non-load-bearing chamber 10. The load-bearing chamber 9 is connected to the non-load-bearing chamber 10 through the first oil path 3 and the fourth oil path 6; the high-pressure hydraulic oil in the load-bearing chamber 9 flows to the non-load-bearing chamber 10 and is throttled by the second throttle valve 25, so that the vehicle body 35 slowly descends.

[0080] The hydraulic control system further includes an oil replenishment accumulator 13, which is connected to the oil drain port of the hydraulic pump 8. As can be seen from the above structure, the oil replenishment accumulator 13 is connected to the oil drain port of the hydraulic pump 8, and the oil replenishment accumulator 13 can collect the hydraulic oil leaked from the hydraulic pump 8 to reduce oil consumption.

[0081] The hydraulic control system further includes a first one-way valve 14 and a second one-way valve 15; the outlet of the oil replenishment accumulator 13 is connected to the inlet of the first one-way valve 14 and the inlet of the second one-way valve 15; the outlet of the first one-way valve 14 is connected to the main oil circuit; the outlet of the second one-way valve 15 is connected to the secondary oil circuit. It can be seen from the above structure that if the hydraulic oil pressure in the load-bearing chamber 9 is too low, the oil replenishment accumulator 13 replenishes oil to the hydraulic pump 8 through the second one-way valve 15 to ensure that the hydraulic pump 8 continuously inhales hydraulic oil; if the hydraulic oil pressure in the non-load-bearing chamber 10 is too low, the oil replenishment accumulator 13 replenishes oil to the hydraulic pump 8 through the first one-way valve 14 to ensure that the hydraulic pump 8 continuously inhales hydraulic oil, thereby improving energy utilization and reaction speed.

[0082] The hydraulic control system further includes a first relief valve 11 and a second relief valve 12; the inlet of the first relief valve 11 is connected to the main oil circuit; the outlet of the first relief valve 11 is connected to the secondary oil circuit; the inlet of the second relief valve 12 is connected to the secondary oil circuit; the outlet of the second relief valve 12 is connected to the main oil circuit. As can be seen from the above structure, if the hydraulic oil pressure in the load-bearing chamber 9 is too high, the second relief valve 12 will release the pressure; if the hydraulic oil pressure in the non-load-bearing chamber 10 is too high, the first relief valve 11 will release the pressure; to ensure the safe operation of the hydraulic control system.

[0083] The hydraulic control system also includes a controller and a force sensor; the force sensor, the third solenoid valve 24, and the servo motor 7 are electrically connected to the controller respectively; the force sensor is used to monitor the load signal of the piston rod 2 and transmit the load signal to the controller; the controller is used to control the switch position of the third solenoid valve 24 and the speed and direction of the servo motor 7. It can be seen from the above structure that when the wheel-legged robot travels on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 increases, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the hydraulic oil pressure in the bearing chamber 9 increases, and the compression of the spring 29 increases, so that the increase in the hydraulic oil pressure in the bearing chamber 9 is buffered. At the same time, the force sensor monitors the load signal of the increased load force of the piston rod 2 and transmits the load signal to the controller; the controller controls the servo motor 7 to rotate forward, and the hydraulic oil in the bearing chamber 9 is sucked to the non-bearing chamber 10 by the hydraulic pump 8, so that the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly shortened, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 The sizes of both become smaller; when the wheel-leg robot travels on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 becomes smaller, the piston rod 2 extends relative to the elongation of the hydraulic cylinder 1, the hydraulic oil pressure in the load-bearing chamber 9 decreases, the compression of the spring 29 decreases, and the rod part of the auxiliary piston rod 2 extends out of the hydraulic cylinder 1. At the same time, the force sensor detects the load signal of the reduced load force of the piston rod 2 and transmits the load signal to the controller; the controller controls the servo motor 7 to reverse, and the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, so that the piston rod 2 extends rapidly relative to the elongation of the hydraulic cylinder 1, and the angle between the body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 both become larger.

[0084] A driving method for a leg joint driving device of a wheel-legged robot, comprising an active vibration reduction step; the active vibration reduction step is specifically as follows: when the wheel 38 touches the ground and rotates, the wheel-legged robot is driven to travel; when the wheel-legged robot travels on a flat ground, the hydraulic oil is not temporarily forced to be exchanged between the load-bearing cavity 9 and the non-load-bearing cavity 10; the load force borne by the hydraulic cylinder 1 and the piston rod 2 does not fluctuate, the vehicle body 35 does not vibrate, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 remains unchanged, the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 remain unchanged, and the spring 29 bears the pressure of the piston rod 2; when the wheel-legged robot travels on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 increases, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 decreases, the hydraulic oil pressure in the load-bearing cavity 9 increases, the compression of the spring 29 increases, so that the increase in the hydraulic oil pressure in the load-bearing cavity 9 is buffered, and at the same time the load-bearing The hydraulic oil is forcibly exchanged between the load-bearing chamber 9 and the non-load-bearing chamber 10, and the hydraulic oil in the load-bearing chamber 9 is sucked into the non-load-bearing chamber 10 by the hydraulic pump 8, so that the extension of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly shortened, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; when the wheel-legged robot travels on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the hydraulic oil pressure in the load-bearing chamber 9 is reduced, the compression of the spring 29 is reduced, and the rod part of the auxiliary piston rod 2 extends out of the hydraulic cylinder 1. At the same time, the hydraulic oil is forcibly exchanged between the load-bearing chamber 9 and the non-load-bearing chamber 10, and the hydraulic oil in the non-load-bearing chamber 10 is sucked into the load-bearing chamber 9 by the hydraulic pump 8, so that the extension of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly extended, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased.

[0085] It also includes an active gait step; the active gait step is specifically as follows: when the wheel-legged robot encounters an obstacle while driving, the hydraulic oil is forcibly exchanged between the load-bearing cavity 9 and the non-load-bearing cavity 10; when the wheel-legged robot is in the process of lifting its legs, the hydraulic oil in the load-bearing cavity 9 is sucked into the non-load-bearing cavity 10 by the hydraulic pump 8, so that the piston rod 2 is rapidly shortened relative to the elongation of the hydraulic cylinder 1, and the angle between the body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; when the wheel-legged robot is in the process of lowering its legs, the hydraulic oil in the non-load-bearing cavity 10 is sucked into the load-bearing cavity 9 by the hydraulic pump 8, so that the piston rod 2 is rapidly extended relative to the elongation of the hydraulic cylinder 1, and the angle between the body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased.

[0086] It also includes a posture adjustment step; the posture adjustment step is specifically as follows: when the wheel-legged robot needs to adjust the height of the vehicle body 35, the hydraulic oil is forcibly exchanged between the load-bearing cavity 9 and the non-load-bearing cavity 10; when the wheel-legged robot needs to increase the height of the vehicle body 35, the hydraulic oil in the non-load-bearing cavity 10 is sucked into the load-bearing cavity 9 by the hydraulic pump 8, and the piston rod 2 is extended relative to the elongation of the hydraulic cylinder 1, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both increased; when the wheel-legged robot needs to lower the height of the vehicle body 35, the hydraulic oil in the load-bearing cavity 9 is sucked into the non-load-bearing cavity 10 by the hydraulic pump 8, and the piston rod 2 is shortened relative to the elongation of the hydraulic cylinder 1, and the angle between the vehicle body 35 and the thigh 36 and the angle between the thigh 36 and the calf 37 are both reduced; the spring 29 always bears the pressure of the piston rod 2.

[0087] It also includes a power-off step; the power-off step is specifically as follows: when the wheel-legged robot loses power, the hydraulic oil is freely exchanged between the load-bearing chamber 9 and the non-load-bearing chamber 10; the high-pressure hydraulic oil in the load-bearing chamber 9 flows to the non-load-bearing chamber 10, causing the vehicle body 35 to slowly descend; at the same time, the spring 29 performs vibration reduction. It can be seen from the above structure that the present invention has multiple working modes. In the posture adjustment step, the height of the vehicle body 35 can be adjusted according to the road conditions to be driven; in the active vibration reduction step, the driving vibration reduction on uphill and downhill roads can be effectively achieved to ensure the stability of the wheel-legged robot during driving; in the active gait step, the leg can be quickly lifted and lowered, obstacles can be crossed, and the stability of the vehicle body 35 can be ensured; the buffering function of the spring 29 and the safety protection function of the first overflow valve 11 and the second overflow valve 12 make the wheel-legged robot run safer and more reliable, and increase its service life. The present invention eliminates the servo valve controlled cylinder, realizes zero throttling loss, and at the same time, during vibration reduction during driving, cleverly utilizes springs to reduce the input power requirement of the joint drive device, reduces the demand for input energy, greatly improves the efficiency of the joint drive, improves the effective energy utilization rate of the robot, and prolongs the cruising time of the robot.

[0088] Embodiment five:

[0089] See attached Figures 1 to 10A wheel-legged robot comprises a body 35, a thigh 36, a shank 37, a wheel 38 and two hydraulic control systems; the hydraulic control system adopts the hydraulic control system of the wheel-legged robot leg joint driving device as described in the above embodiment; one end of the thigh 36 is hinged to the body 35, and the other end of the thigh 36 is hinged to one end of the shank 37; the other end of the shank 37 is provided with a wheel 38; the two hydraulic control systems respectively control the angle between the body 35 and the thigh 36, and the angle between the thigh 36 and the shank 37. It can be seen from the above structure that the vehicle body 35 is the body part of the wheel-legged robot, and the moving state of the vehicle body 35 is mainly completed by the legs of the wheel-legged robot. The legs can have one pair or two pairs, and the legs are a combination of thighs 36, calves 37, and wheels 38; one end of the thigh 36 is hinged to the vehicle body 35, and this hinge can be directly hinged through a rotating shaft, or it can be indirectly hinged through a hip joint; the other end of the thigh 36 is hinged to one end of the calf 37, and this hinge can be directly hinged through a rotating shaft, or it can be indirectly hinged through a knee joint; the other end of the calf 37 is provided with a wheel 38, and the rotation of the wheel 38 enables the leg to carry the vehicle body 35 forward or backward The leg part is provided with two hydraulic control systems; one hydraulic control system controls the angle between the vehicle body 35 and the thigh 36, for example, keeps the angle unchanged, increases or decreases; the other hydraulic control system controls the angle between the thigh 36 and the calf 37, for example, keeps the angle unchanged, increases or decreases; the two hydraulic control systems respectively control the angle between the vehicle body 35 and the thigh 36, and the angle between the thigh 36 and the calf 37, so that the wheel 38 can be adjusted to move forward, backward, upward or downward relative to the vehicle body 35; the corresponding hydraulic control systems of the vehicle body 35 and the thigh 36 , the two ends of the matching assembly of the hydraulic cylinder 1 and the piston rod 2 are respectively hinged to the vehicle body 35 and the thigh 36, so that the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the angle between the vehicle body 35 and the thigh 36 becomes smaller, and the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is extended, and the angle between the vehicle body 35 and the thigh 36 becomes larger, and the elongation of the piston rod 2 relative to the hydraulic cylinder 1 remains unchanged, and the angle between the vehicle body 35 and the thigh 36 remains unchanged; in the hydraulic control system corresponding to the thigh 36 and the shank 37, the two ends of the matching assembly of the hydraulic cylinder 1 and the piston rod 2 are respectively hinged to the thigh 36 and the shank 37, so that the piston rod 2 relative to the hydraulic cylinder When the extension of the hydraulic cylinder 1 is shortened, the angle between the thigh 36 and the shank 37 becomes smaller. When the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the angle between the thigh 36 and the shank 37 becomes larger. When the extension of the piston rod 2 relative to the hydraulic cylinder 1 remains unchanged, the angle between the thigh 36 and the shank 37 remains unchanged. In this way, two hydraulic control systems are implemented to control the angle between the vehicle body 35 and the thigh 36, and the angle between the thigh 36 and the shank 37, respectively, so that the wheel 38 can be adjusted to move forward, backward, upward, and downward relative to the vehicle body 35. A load-bearing chamber 9 and a non-load-bearing chamber 10 are provided in the hydraulic cylinder 1.The piston rod 2 separates the load-bearing chamber 9 and the non-load-bearing chamber 10; the extension of the piston rod 2 relative to the hydraulic cylinder 1 changes with the change of the hydraulic oil capacity in the load-bearing chamber 9 and the non-load-bearing chamber 10; if the hydraulic oil capacity of the load-bearing chamber 9 increases and the hydraulic oil capacity of the non-load-bearing chamber 10 decreases, the extension of the piston rod 2 relative to the hydraulic cylinder 1 increases; if the hydraulic oil capacity of the load-bearing chamber 9 decreases and the hydraulic oil capacity of the non-load-bearing chamber 10 increases, the extension of the piston rod 2 relative to the hydraulic cylinder 1 decreases; if the hydraulic oil capacity of the load-bearing chamber 9 and the non-load-bearing chamber 10 remains unchanged, the extension of the piston rod 2 relative to the hydraulic cylinder 1 remains unchanged.;

[0090] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A leg joint driving device for a wheel-legged robot, characterized in that: The invention comprises a hydraulic control system; the hydraulic control system comprises a hydraulic cylinder (1), a piston rod (2), a main oil circuit, a secondary oil circuit, a servo motor (7) and a hydraulic pump (8); a load-bearing chamber (9) and a non-load-bearing chamber (10) are arranged in the hydraulic cylinder (1); the piston rod (2) separates the load-bearing chamber (9) and the non-load-bearing chamber (10); the servo motor (7) is used to drive the hydraulic pump (8); the non-load-bearing chamber (10), the main oil circuit, the hydraulic pump (8), the secondary oil circuit and the load-bearing chamber (9) are connected in sequence; the extension amount of the piston rod (2) relative to the hydraulic cylinder (1) changes with the change of the hydraulic oil capacity in the load-bearing chamber (9) and the non-load-bearing chamber (10); the hydraulic control system further comprises a first relief valve (11) and a second relief valve (12); the inlet of the first relief valve (11) is connected to the main oil circuit; the outlet of the first relief valve (11) is connected to the secondary oil circuit; the inlet of the second relief valve (12) is connected to the secondary oil circuit; the outlet of the second relief valve (12) is connected to the secondary oil circuit; the outlet of the second relief valve (12) is connected to the secondary oil circuit. The outlet is connected to the main oil circuit; the hydraulic control system also includes a third solenoid valve (24); the main oil circuit includes the first oil circuit (3) and the second oil circuit (4); the secondary oil circuit includes the third oil circuit (5) and the fourth oil circuit (6); the third solenoid valve (24) is a two-position four-way solenoid switch valve; the third solenoid valve (24) includes a3 port, b3 port, c3 port and d3 port; the two ends of the first oil circuit (3) are respectively connected to the a3 port and the non-load-bearing cavity (10); the second oil circuit (4) two ends are connected to port b3 and the hydraulic pump (8); two ends of the third oil circuit (5) are connected to port c3 and the hydraulic pump (8); two ends of the fourth oil circuit (6) are connected to port d3 and the bearing chamber (9); when the third solenoid valve (24) is in an energized state, except that ports a3 and b3 are connected, and ports c3 and d3 are connected, the other ports are not connected; when the third solenoid valve (24) is in a de-energized state, except that ports a3 and d3 are connected, the other ports are not connected.

2. The leg joint driving device of a wheel-legged robot according to claim 1, characterized in that: The hydraulic control system further comprises an oil replenishment accumulator (13); the hydraulic control system further comprises a first one-way valve (14) and a second one-way valve (15); the outlet of the oil replenishment accumulator (13) is connected to the inlet of the first one-way valve (14) and the inlet of the second one-way valve (15); the outlet of the first one-way valve (14) is connected to the main oil circuit; the outlet of the second one-way valve (15) is connected to the secondary oil circuit.

3. The leg joint driving device of a wheel-legged robot according to claim 2, characterized in that: The hydraulic control system further comprises a high-pressure accumulator (16), a high-pressure oil circuit and a low-pressure oil circuit; the outlet of the oil replenishment accumulator (13) is connected to the non-load-bearing chamber (10) through the low-pressure oil circuit; the outlet of the high-pressure accumulator (16) is connected to the load-bearing chamber (9) through the high-pressure oil circuit.

4. The leg joint driving device of a wheel-legged robot according to claim 3, characterized in that: The hydraulic control system further comprises a first solenoid valve (22) and a second solenoid valve (21); the low-pressure oil circuit comprises a fifth oil circuit (17) and a sixth oil circuit (18); the high-pressure oil circuit comprises a seventh oil circuit (19) and an eighth oil circuit (20); the second solenoid valve (21) is a two-position four-way solenoid switch valve; the second solenoid valve (21) comprises a2 port, b2 port, c2 port and d2 port; the two ends of the fifth oil circuit (17) are respectively connected to the a2 port and the oil replenishment accumulator (13); the two ends of the sixth oil circuit (18) are respectively connected to the b2 port and the non-load-bearing chamber (10); the two ends of the seventh oil circuit (19) are respectively connected to the c2 port and the high-pressure accumulator (16); the two ends of the eighth oil circuit (20) are respectively connected to the d2 port and the load-bearing chamber (9); when the second solenoid valve (21) is in a de-energized state, except that the a2 port and the b2 port are connected, and the c2 port and the d2 port are connected, the other ports are not connected; the second When the solenoid valve (21) is in a state of being ...

5. The leg joint driving device of a wheel-legged robot according to claim 1, characterized in that: The hydraulic control system further comprises a second high-pressure accumulator (26); the second high-pressure accumulator (26) is connected to the bearing chamber (9) via an oil circuit.

6. The leg joint driving device of a wheel-legged robot according to claim 1, characterized in that: The hydraulic control system further comprises a controller and a force sensor; the force sensor, the third solenoid valve (24), and the servo motor (7) are electrically connected to the controller respectively; the force sensor is used to monitor the load signal of the piston rod (2) and transmit the load signal to the controller; the controller is used to control the switch position of the third solenoid valve (24) and the speed and direction of the servo motor (7).

7. The leg joint driving device of a wheel-legged robot according to claim 1, characterized in that: The hydraulic cylinder (1) is provided with a guide rod (27); the piston rod (2) is hollow inside and is sleeved on the guide rod (27); the load-bearing chamber (9) is located at the top of the guide rod (27) and is surrounded by the rod portion of the piston rod (2); a guide passage (28) is provided in the guide rod (27); the guide passage (28) connects the load-bearing chamber (9) and the fourth oil circuit (6); a spring (29) is sleeved on the guide rod (27); the spring (29) is compressed between the plug portion of the piston rod (2) and the bottom of the hydraulic cylinder (1); the non-load-bearing chamber (10) is located between the rod portion of the piston rod (2) and the hydraulic cylinder (1).

8. The leg joint driving device of a wheel-legged robot according to claim 1, characterized in that: The hydraulic control system further comprises a fourth solenoid valve (30) and a motor gear control system; the main oil circuit comprises a first oil circuit (3) and a second oil circuit (4); the secondary oil circuit comprises a third oil circuit (5) and a fourth oil circuit (6); the fourth solenoid valve (30) is a two-position two-way solenoid switch valve; the fourth solenoid valve (30) comprises an a4 port and a b4 port; the non-load-bearing chamber (10), the first oil circuit (3), the second oil circuit (4), the hydraulic pump (8), the third oil circuit (5), the fourth oil circuit (6) and the load-bearing chamber (9) are connected in sequence; the first oil circuit (3) and the second oil circuit (4) are connected to the a4 port; the third oil circuit (5 ) and the fourth oil circuit (6) are connected to port b4; when the fourth solenoid valve (30) is in an electrical potential, ports a4 and b4 are not connected; when the fourth solenoid valve (30) is in an electrical potential-free potential, ports a4 and b4 are connected; the motor gear control system comprises a driving motor (31), a reducer (32), a self-rotating gear (33) and a fixed gear (34); the self-rotating gear (33) and the fixed gear (34) are meshed; the driving motor (31) is used to drive the reducer (32) to drive the self-rotating gear (33) to rotate; when the self-rotating gear (33) rotates, the self-rotating gear (33) rotates relatively around the fixed gear (34).

9. A wheel-legged robot, characterized in that: It comprises a vehicle body (35), a thigh (36), a calf (37), a wheel (38) and two hydraulic control systems; the hydraulic control system adopts the hydraulic control system of the wheel-leg robot leg joint drive device as claimed in claim 1; one end of the thigh (36) is hinged to the vehicle body (35), and the other end of the thigh (36) is hinged to one end of the calf (37); a wheel (38) is provided at the other end of the calf (37); the two hydraulic control systems respectively control the angle between the vehicle body (35) and the thigh (36), and the angle between the thigh (36) and the calf (37).

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