CN112460085A

CN112460085A - Wheel-leg robot and leg joint driving device thereof

Info

Publication number: CN112460085A
Application number: CN202011427718.0A
Authority: CN
Inventors: 胡小东; 徐彬; 秦也辰; 刘辉; 项昌乐; 杨海洋; 刘春桃
Original assignee: Beijing Institute of Technology BIT; Chongqing Innovation Center of Beijing University of Technology
Current assignee: Beijing Institute of Technology BIT; Chongqing Innovation Center of Beijing University of Technology
Priority date: 2020-12-09
Filing date: 2020-12-09
Publication date: 2021-03-09

Abstract

The invention discloses a wheel-leg robot and a leg joint driving device thereof, belonging to the technical field of wheel-leg robots and comprising a hydraulic control system; the hydraulic control system comprises a hydraulic cylinder, a piston rod, a main oil way, a secondary oil way, a servo motor and a hydraulic pump; a bearing cavity and a non-bearing cavity are arranged in the hydraulic cylinder; the piston rod separates a bearing cavity and a non-bearing cavity; the servo motor is used for driving the hydraulic pump; the non-bearing cavity, the main oil way, the hydraulic pump, the secondary oil way and the bearing cavity are communicated in sequence; the elongation of the piston rod relative to the hydraulic cylinder changes along with the change of the volume of the hydraulic oil in the bearing cavity and the non-bearing cavity. The wheel-legged robot and the leg joint driving device thereof have the advantages of no overflow loss, no throttling loss, system power saving, high transmission efficiency of a hydraulic system, high energy utilization rate, good buffering performance and long service life.

Description

Wheel-leg robot and leg joint driving device thereof

Technical Field

The invention belongs to the technical field of wheel-leg robots, and particularly relates to a wheel-leg robot and a leg joint driving device thereof.

Background

The wheel-leg robot is characterized in that wheels are added at the tail ends of the robot legs, the advantages of the wheels and the legs are fully combined, the robot can quickly and efficiently pass through a vehicle road surface, and can cross over an obstacle by using the gait of the legs to realize passing under a non-structural environment. Since a legged robot has a higher traveling speed in a road environment than a legged robot, research on the legged robot has drawn more and more attention.

At present, the research of the wheel-leg robot is mainly focused on a small wheel-leg robot platform, the robot body and the load capacity are small, and a motor can be applied to a speed reducer combination to drive the joint of the leg; for the leg joint driving of the medium/large-sized wheel-leg robot, a servo valve control cylinder is adopted for driving, a servo valve is installed on a hydraulic cylinder, a piston rod of the hydraulic cylinder drives the leg joint through a connecting rod, 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 the size of a valve core opening of the servo valve, and further the torque/rotating speed of the leg joint is controlled.

The middle/large wheel-leg robot adopts a servo valve control cylinder as a joint driving device and has the following problems:

1. in a hydraulic system adopting a servo valve control cylinder as a wheel leg robot joint actuator, a centralized pump station is adopted as a power source, an overflow valve is required to overflow to maintain constant pressure in order to maintain constant system pressure in a pump station part, and the pump station part always has overflow loss in such a way, so that the power loss of the system is brought.

2. The servo valve control cylinder realizes accurate output force/speed control on the hydraulic cylinder through throttling of the servo valve, large throttling power loss exists, the transmission efficiency of a hydraulic system is low, and the effective energy utilization rate of the robot is low. In the driving process of a general wheel-leg robot, the output torque of a joint driving device of the robot needs to overcome the gravity and the inertia force of the robot, so that a larger torque is needed, a hydraulic actuator needs to be adopted for driving, and a higher power density ratio can be achieved; however, when the robot with wheel legs executes gait crossing obstacles, only the weight of the legs needs to be overcome for the joint driving device, so that the output torque of the joint driving device required at the moment is smaller, and if a servo valve cylinder control actuator is adopted, a great differential pressure can be generated at the valve port of the servo valve, and great throttling loss is generated.

3. The joint driving device system composed of the servo valve control cylinder and the centralized pump station is complex in composition, and the servo valve is poor in oil pollution resistance, so that the reliability of the whole joint driving device is poor.

4. The servo valve control cylinder is a rigid execution mechanism consisting of a servo valve and a hydraulic cylinder, when the wheel-leg robot meets a protrusion in the ground running process, instantaneous force impact can be generated on a joint actuator, and because the servo valve control cylinder is not provided with a passive buffer device, instantaneous pressure peak values can be generated in the hydraulic cylinder under the instantaneous force impact, and the pressure peak values can damage hydraulic components and sealing.

5. The servo valve control cylinder driving device cannot normally work after the robot system loses power, and is inconvenient to transport.

6. The joint driving device system composed of the servo valve control cylinder and the centralized pump station is complex in composition, and the servo valve is poor in oil pollution resistance, so that the reliability of the whole joint driving device is poor.

Disclosure of Invention

The invention aims to provide a wheel-leg robot and a leg joint driving device thereof aiming at the defects, and aims to solve the problems that how to be applied to the leg joint driving of a medium/large wheel-leg robot, a servo valve control cylinder is cancelled, no throttling loss is realized, meanwhile, the efficiency of a joint driver is improved, the effective energy utilization rate of the robot is improved, the cruising time of the robot is prolonged and the like during vibration reduction in the driving process. In order to achieve the purpose, the invention provides the following technical scheme:

a leg joint driving device of a wheel-legged robot comprises a hydraulic control system; the hydraulic control system comprises a hydraulic cylinder 1, a piston rod 2, a main oil way, a secondary oil way, a servo motor 7 and a hydraulic pump 8; a bearing cavity 9 and a non-bearing cavity 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates a bearing cavity 9 and a non-bearing cavity 10; the servo motor 7 is used for driving a hydraulic pump 8; the non-bearing cavity 10, the main oil way, the hydraulic pump 8, the secondary oil way and the bearing cavity 9 are communicated in sequence; the elongation of the piston rod 2 relative to the cylinder 1 changes with the change of the volume of hydraulic oil in the load bearing chamber 9 and the non-load bearing chamber 10.

Further, the hydraulic control system further comprises a first overflow valve 11 and a second overflow valve 12; the inlet of the first overflow valve 11 is communicated with a main oil way; the outlet of the first overflow valve 11 is communicated with a secondary oil way; the inlet of the second overflow valve 12 is communicated with a secondary oil way; the outlet of the second overflow valve 12 is communicated with a main oil way.

Further, the hydraulic control system further comprises an oil supplementing accumulator 13; the hydraulic control system further comprises a first check valve 14 and a second check valve 15; the outlet of the oil supplementing accumulator 13 is communicated with the inlet of a first one-way valve 14 and the inlet of a second one-way valve 15; the outlet of the first one-way valve 14 is communicated with a main oil way; the outlet of the second check valve 15 is communicated with a secondary oil path.

Further, the hydraulic control system further comprises a high-pressure accumulator 16, a high-pressure oil path and a low-pressure oil path; the outlet of the oil supplementing accumulator 13 is communicated with the non-bearing cavity 10 through a low-pressure oil way; the outlet of the high-pressure accumulator 16 is communicated with the bearing cavity 9 through a high-pressure oil path.

Further, the hydraulic control system further comprises a first solenoid valve 22 and a second solenoid valve 21; the low-pressure oil passages include a fifth oil passage 17 and a sixth oil passage 18; the high-pressure oil passage includes a seventh oil passage 19 and an eighth oil passage 20; the second electromagnetic valve 21 is a two-position four-way electromagnetic switch valve; the second solenoid valve 21 includes a2 port, b2 port, c2 port and d2 port; two ends of the fifth oil path 17 are respectively communicated with an a2 port and the oil supplementing accumulator 13; two ends of the sixth oil path 18 are respectively communicated with a port b2 and the non-bearing cavity 10; two ends of the seventh oil passage 19 are respectively communicated with a port c2 and the high-pressure accumulator 16; two ends of the eighth oil path 20 are respectively communicated with a port d2 and the bearing cavity 9; when the second electromagnetic valve 21 is at a non-potential state, the ports except the port a2 and the port b2 are conducted, and the port c2 and the port d2 are conducted, and the other ports are not conducted; when the second electromagnetic valve 21 is at a potential, all ports are not conducted; the main oil passage comprises a first oil passage 3 and a second oil passage 4; the secondary oil passages include a third oil passage 5 and a fourth oil passage 6; the first electromagnetic valve 22 is a two-position four-way electromagnetic switch valve; the first solenoid valve 22 includes a1 port, b1 port, c1 port and d1 port; two ends of the first oil path 3 are respectively communicated with an a1 port and a non-bearing cavity 10; two ends of the second oil path 4 are respectively communicated with a port b1 and the hydraulic pump 8; the two ends of the third oil path 5 are respectively communicated with a port c1 and a hydraulic pump 8; two ends of the fourth oil path 6 are respectively communicated with a port d1 and the bearing cavity 9; when the first electromagnetic valve 22 is at a potential, the ports except the port a1 and the port b1 are conducted, and the port c1 and the port d1 are conducted, and the rest ports are not conducted; when the first electromagnetic valve 22 is at a loss of potential, all the ports are not conducted.

Further, the hydraulic control system further includes a third solenoid valve 24; the main oil passage comprises a first oil passage 3 and a second oil passage 4; the secondary oil passages include a third oil passage 5 and a fourth oil passage 6; the third electromagnetic valve 24 is a two-position four-way electromagnetic switch valve; the third solenoid valve 24 includes a3 port, b3 port, c3 port and d3 port; two ends of the first oil path 3 are respectively communicated with an a3 port and a non-bearing cavity 10; two ends of the second oil path 4 are respectively communicated with a port b3 and the hydraulic pump 8; the two ends of the third oil path 5 are respectively communicated with a port c3 and a hydraulic pump 8; two ends of the fourth oil path 6 are respectively communicated with a port d3 and the bearing cavity 9; when the third electromagnetic valve 24 is at a potential, the ports except the port a3 and the port b3 are conducted, and the port c3 and the port d3 are conducted, and the rest ports are not conducted; when the third electromagnetic valve 24 is at a non-potential state, the port a3 and the port d3 are not communicated with each other.

Further, the hydraulic control system further includes a second high pressure accumulator 26; the second high-pressure accumulator 26 is communicated with the bearing cavity 9 through an oil path.

Further, the hydraulic control system further comprises a controller and a force sensor; the force sensor, the third electromagnetic valve 24 and the servo motor 7 are respectively and electrically connected with the controller; the force sensor is used for monitoring a load signal of the piston rod 2 and transmitting the load signal to the controller; the controller is used for controlling the switch position of the third electromagnetic valve 24 and the rotating speed and the direction of the servo motor 7.

Further, a guide rod 27 is arranged in the hydraulic cylinder 1; the piston rod 2 is hollow inside and sleeved outside the guide rod 27; the bearing chamber 9 is positioned on top of the guide rod 27 and is surrounded by the rod part of the piston rod 2; a conduction path 28 is arranged in the guide rod 27; the conducting path 28 is communicated with the bearing cavity 9 and the fourth oil path 6; a spring 29 is sleeved outside the guide rod 27; the spring 29 is compressed between the plug part 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.

Further, the hydraulic control system also comprises a fourth electromagnetic valve 30 and a motor gear control system; the main oil passage comprises a first oil passage 3 and a second oil passage 4; the secondary oil passages include a third oil passage 5 and a fourth oil passage 6; the fourth electromagnetic valve 30 is a two-position two-way electromagnetic switch valve; the fourth solenoid valve 30 includes a port 4 and a port b 4; the non-bearing cavity 10, the first oil way 3, the second oil way 4, the hydraulic pump 8, the third oil way 5, the fourth oil way 6 and the bearing cavity 9 are communicated in sequence; the first oil passage 3 and the second oil passage 4 are communicated with a port a 4; the third oil passage 5 and the fourth oil passage 6 are communicated with a port b 4; when the fourth electromagnetic valve 30 is at a potential, the port a4 and the port b4 are not conducted; when the fourth electromagnetic valve 30 is at a loss of potential, the port a4 is communicated with the port b 4; the motor gear control system comprises a driving motor 31, a speed reducer 32, a rotation gear 33 and a fixed gear 34; the rotation gear 33 is meshed with the fixed gear 34; the driving motor 31 is used for driving the reducer 32 to drive the rotation gear 33 to rotate; when the rotation gear 33 rotates, the rotation gear 33 relatively rotates around the fixed gear 34.

A wheel-leg robot includes a vehicle body 35, thighs 36, calves 37, wheels 38, and two hydraulic control systems; the hydraulic control system adopts the hydraulic control system of the leg joint driving device of the wheel-leg robot; one end of the thigh 36 is hinged with the vehicle body 35, and the other end of the thigh 36 is hinged with 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 size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37.

The invention has the beneficial effects that:

Drawings

FIG. 1 is a schematic structural diagram of a hydraulic control system in a passive damping step according to a first embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a hydraulic control system in an attitude adjustment step according to a first embodiment of the present invention;

FIG. 3 is a schematic diagram of the hydraulic control system of the present invention in an active gait step according to a first embodiment;

FIG. 4 is a schematic structural diagram of the wheel-legged robot in the active/passive damping step and the attitude adjustment step according to the first, second and fourth embodiments of the present invention;

FIG. 5 is a schematic structural diagram of the wheel-legged robot of the first, second and fourth embodiments of the present invention in the step of active gait;

FIG. 6 is a schematic structural diagram of a hydraulic control system according to a second embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a hydraulic control system according to a third embodiment of the present invention;

FIG. 8 is a schematic structural view of a wheel-legged robot in the third embodiment, during the active vibration reduction step and the attitude adjustment step;

FIG. 9 is a schematic structural view of the wheel-legged robot of the present invention in the step of active gait in the third embodiment;

FIG. 10 is a schematic structural diagram of a hydraulic control system according to a fourth embodiment of the present invention;

in the drawings: 1-hydraulic cylinder, 2-piston rod, 3-first oil way, 4-second oil way, 5-third oil way, 6-fourth oil way, 7-servo motor, 8-hydraulic pump, 9-bearing cavity, 10-non-bearing cavity, 11-first overflow valve, 12-second overflow valve, 13-oil supplementing accumulator, 14-first check valve, 15-second check valve, 16-high-pressure accumulator, 17-fifth oil way, 18-sixth oil way, 19-seventh oil way, 20-eighth oil way, 21-second electromagnetic valve, 22-first electromagnetic valve, 23-first throttle valve, 24-third electromagnetic valve, 25-second throttle valve, 26-second high-pressure accumulator, 27-guide rod, 28-conducting way, 29-spring, 30-fourth electromagnetic valve, 31-driving motor, 32-speed reducer, 33-rotation gear, 34-fixed gear, 35-vehicle body, 36-thigh, 37-shank and 38-wheel.

Detailed Description

The present invention will be described in further detail below with reference to the drawings and the embodiments, but the present invention is not limited to the following examples.

The first embodiment is as follows:

see figures 1-5. A leg joint driving device of a wheel-legged robot comprises a hydraulic control system; the hydraulic control system comprises a hydraulic cylinder 1, a piston rod 2, a main oil way, a secondary oil way, a servo motor 7 and a hydraulic pump 8; a bearing cavity 9 and a non-bearing cavity 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates a bearing cavity 9 and a non-bearing cavity 10; the servo motor 7 is used for driving a hydraulic pump 8; the non-bearing cavity 10, the main oil way, the hydraulic pump 8, the secondary oil way and the bearing cavity 9 are communicated in sequence; the elongation of the piston rod 2 relative to the cylinder 1 changes with the change of the volume of hydraulic oil in the load bearing chamber 9 and the non-load bearing chamber 10. According to the structure, if the lines formed by the non-bearing cavity 10, the main oil way, the hydraulic pump 8, the secondary oil way and the bearing cavity 9 are communicated in sequence, the servo motor 7 rotates forwards, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are reduced; the servo motor 7 rotates reversely, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the piston rod 2 extends relative to the elongation of the hydraulic cylinder 1, and the size of an included angle between the car body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are increased. And a servo valve control cylinder is cancelled, so that no throttling loss is realized.

The hydraulic control system also comprises an oil supplementing accumulator 13, a high-pressure accumulator 16, a high-pressure oil way and a low-pressure oil way; the outlet of the oil supplementing accumulator 13 is communicated with the non-bearing cavity 10 through a low-pressure oil way; the outlet of the high-pressure accumulator 16 is communicated with the bearing cavity 9 through a high-pressure oil path. According to the structure, the outlet of the oil supplementing accumulator 13 is communicated to the non-bearing cavity 10 through a low-pressure oil way; the outlet of the high-pressure accumulator 16 is communicated to the bearing cavity 9 through a high-pressure oil path; when the wheel 38 rotates in a grounding way, the robot with wheel legs is driven to run; when the wheel-leg robot runs on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is increased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the pressure of hydraulic oil in the bearing cavity 9 is increased, the hydraulic oil with the increased pressure enters the high-pressure energy accumulator 16 through the high-pressure oil path, the pressure increase of the hydraulic oil in the bearing cavity 9 is buffered, and meanwhile, the hydraulic oil of the oil supplementing energy accumulator 13 is supplemented with oil to the non-bearing cavity 10 through the low-pressure oil path; when the wheel-leg robot runs on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the piston rod 2 extends relative to the elongation of the hydraulic cylinder 1, the pressure of hydraulic oil in the bearing cavity 9 is reduced, the hydraulic oil in the high-pressure energy accumulator 16 enters the bearing cavity 9 through a high-pressure oil path for oil supplement, so that the pressure reduction of the hydraulic oil in the bearing cavity 9 is buffered, and meanwhile, the hydraulic oil in the non-bearing cavity 10 flows to the oil supplement energy accumulator 13 through a low-pressure oil path; the oil supplementing energy accumulator 13 and the high-pressure energy accumulator 16 realize vibration reduction in the running process of the wheel-leg robot, so that the stability of the vehicle body is ensured, vibration energy is absorbed, the influence on the wheel-leg robot is reduced, and the service life of the wheel-leg robot is prolonged.

The hydraulic control system further comprises a second solenoid valve 21; the low-pressure oil passages include a fifth oil passage 17 and a sixth oil passage 18; the high-pressure oil passage includes a seventh oil passage 19 and an eighth oil passage 20; the second electromagnetic valve 21 is a two-position four-way electromagnetic switch valve; the second solenoid valve 21 includes a2 port, b2 port, c2 port and d2 port; two ends of the fifth oil path 17 are respectively communicated with an a2 port and the oil supplementing accumulator 13; two ends of the sixth oil path 18 are respectively communicated with a port b2 and the non-bearing cavity 10; two ends of the seventh oil passage 19 are respectively communicated with a port c2 and the high-pressure accumulator 16; two ends of the eighth oil path 20 are respectively communicated with a port d2 and the bearing cavity 9; when the second electromagnetic valve 21 is at a non-potential state, the ports except the port a2 and the port b2 are conducted, and the port c2 and the port d2 are conducted, and the other ports are not conducted; when the second electromagnetic valve 21 is at a potential, all the ports are not conducted. As can be seen from the above structure, when the second electromagnetic valve 21 is at a de-potential state, the ports a2 and b2 are connected, the port c2 and the port d2 are connected, and the other ports are not connected, that is, the port a2, the port c2, the port d2, the port b2, the port c2 and the port d2 are not connected, and the outlet of the oil supply accumulator 13 is connected to the non-load bearing chamber 10 sequentially through the fifth oil passage 17, the sixth oil passage 18; an outlet of the high-pressure accumulator 16 is communicated with the bearing cavity 9 sequentially through a seventh oil passage 19 and an eighth oil passage 20; the oil supplementing energy accumulator 13 and the high-pressure energy accumulator 16 can play a role of buffering, and the hydraulic oil pressure of the oil supplementing energy accumulator 13 changes along with the change of the hydraulic oil pressure of the non-bearing cavity 10; the hydraulic oil pressure of the high-pressure accumulator 16 changes along with the change of the hydraulic oil pressure of the bearing cavity 9; when the second electromagnetic valve 21 is at a potential, all the ports are not communicated, and the oil supplement energy accumulator 13 and the high-pressure energy accumulator do not play a role in vibration buffering any more.

The hydraulic control system further comprises a first solenoid valve 22; the main oil passage comprises a first oil passage 3 and a second oil passage 4; the secondary oil passages include a third oil passage 5 and a fourth oil passage 6; the first electromagnetic valve 22 is a two-position four-way electromagnetic switch valve; the first solenoid valve 22 includes a1 port, b1 port, c1 port and d1 port; two ends of the first oil path 3 are respectively communicated with an a1 port and a non-bearing cavity 10; two ends of the second oil path 4 are respectively communicated with a port b1 and the hydraulic pump 8; the two ends of the third oil path 5 are respectively communicated with a port c1 and a hydraulic pump 8; two ends of the fourth oil path 6 are respectively communicated with a port d1 and the bearing cavity 9; when the first electromagnetic valve 22 is at a potential, the ports except the port a1 and the port b1 are conducted, and the port c1 and the port d1 are conducted, and the rest ports are not conducted; when the first electromagnetic valve 22 is at a loss of potential, all the ports are not conducted. As can be seen from the above structure, when the first electromagnetic valve 22 is at a voltage, the ports a1 and b1 are connected, the port c1 and the port d1 are connected, and the other ports are not connected, that is, the ports a1, c1, d1, b1, c1, and d1 are not connected, and the lines formed by the non-load-bearing chamber 10, the first oil path 3, the second oil path 4, the hydraulic pump 8, the third oil path 5, the fourth oil path 6, and the load-bearing chamber 9 are connected, so that 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 electromagnetic valve 22 is at a loss of potential, the first oil path 3 and the second oil path 4 are not communicated; the third oil path 5 and the fourth oil path 6 are not communicated; the servo motor 7 and the hydraulic pump 8 are in an inoperative state.

The oil supplementing energy accumulator 13 is communicated with an oil drainage port of the hydraulic pump 8; the hydraulic control system further comprises a first check valve 14 and a second check valve 15; the outlet of the oil supplementing accumulator 13 is communicated with the inlet of a first one-way valve 14 and the inlet of a second one-way valve 15; the outlet of the first one-way valve 14 is communicated with a main oil way; the outlet of the second check valve 15 is communicated with a secondary oil path. According to the structure, the oil supplementing energy accumulator 13 is communicated with the oil drainage port of the hydraulic pump 8, and the oil supplementing energy accumulator 13 can collect the hydraulic oil leaked by the hydraulic pump 8, so that the oil consumption is reduced; if the pressure of the hydraulic oil in the bearing cavity 9 is too low, the oil supplementing energy accumulator 13 supplements oil to the hydraulic pump 8 through the second one-way valve 15, so that the hydraulic pump 8 is ensured to continuously suck the hydraulic oil; if the pressure of the hydraulic oil in the non-bearing cavity 10 is too low, the oil supplementing energy accumulator 13 supplements oil to the hydraulic pump 8 through the first one-way valve 14, so that the hydraulic pump 8 is ensured to continuously suck the hydraulic oil; thereby improving the energy utilization rate and the reaction speed.

The hydraulic control system further comprises a first overflow valve 11 and a second overflow valve 12; the inlet of the first overflow valve 11 is communicated with a main oil way; the outlet of the first overflow valve 11 is communicated with a secondary oil way; the inlet of the second overflow valve 12 is communicated with a secondary oil way; the outlet of the second overflow valve 12 is communicated with a main oil way. According to the structure, if the pressure of the hydraulic oil in the bearing cavity 9 is too high, the second overflow valve 12 is decompressed; if the pressure of the hydraulic oil in the non-bearing cavity 10 is too high, the first overflow valve 11 is decompressed; the operation safety of the hydraulic control system is ensured.

And a first throttle valve 23 is arranged on the high-pressure oil path. With the above structure, the first throttle 23 slows down 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.

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

A driving method of a leg joint driving device of a wheel-legged robot comprises a passive vibration reduction step; the passive vibration reduction step specifically comprises the following steps: when the wheel 38 rotates in a grounding way, the robot with wheel legs is driven to run; the low-pressure oil way is communicated, and the outlet of the oil supplementing accumulator 13 is communicated with the non-bearing cavity 10 through the low-pressure oil way; the high-pressure oil way is communicated, and the outlet of the high-pressure energy accumulator 16 is communicated with the bearing cavity 9 through the high-pressure oil way; hydraulic oil is not exchanged between the bearing cavity 9 and the non-bearing cavity 10; when the wheel-legged robot runs on a flat ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is not fluctuated, the vehicle body 35 is not vibrated, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is kept unchanged, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are kept unchanged; when the wheel-leg robot runs on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is increased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the pressure of hydraulic oil in the bearing cavity 9 is increased, the hydraulic oil with the increased pressure enters the high-pressure energy accumulator 16 through the high-pressure oil path, the pressure increase of the hydraulic oil in the bearing cavity 9 is buffered, meanwhile, the hydraulic oil in the oil supplementing energy accumulator 13 is supplemented to the non-bearing cavity 10 through the low-pressure oil path, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are both reduced; when the wheel-leg robot runs on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the piston rod 2 extends relative to the extension of the hydraulic cylinder 1, the pressure of hydraulic oil in the bearing cavity 9 is reduced, the hydraulic oil in the high-pressure energy accumulator 16 enters the bearing cavity 9 through a high-pressure oil line for oil supplement, so that the pressure reduction of the hydraulic oil in the bearing cavity 9 is buffered, meanwhile, the hydraulic oil in the non-bearing cavity 10 flows to the oil supplement energy accumulator 13 through a low-pressure oil line, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are increased.

Also comprises an active gait step; the active gait steps are specifically as follows: when the robot with wheel legs encounters an obstacle during running, the low-pressure oil way is disconnected, and the outlet of the oil supplementing energy accumulator 13 cannot be communicated with the non-bearing cavity 10 through the low-pressure oil way; the high-pressure oil way is disconnected, and the outlet of the high-pressure energy accumulator 16 cannot be communicated with the bearing cavity 9 through the high-pressure oil way; hydraulic oil is forcibly exchanged between the bearing cavity 9 and the non-bearing cavity 10; when the wheel-leg robot lifts the legs, the hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are both reduced; when the robot with wheel legs falls on the legs, the hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, and the size of the included angle between the vehicle body 35 and the thigh 36 and the size of the included angle between the thigh 36 and the shank 37 are increased.

Also comprises a posture adjusting step; the posture adjusting step specifically comprises the following steps: when the wheel-leg robot needs to adjust the height of the vehicle body 35, the low-pressure oil way is communicated, and the outlet of the oil supplementing energy accumulator 13 is communicated with the non-bearing cavity 10 through the low-pressure oil way; the high-pressure oil way is communicated, and the outlet of the high-pressure energy accumulator 16 is communicated with the bearing cavity 9 through the high-pressure oil way; hydraulic oil is forcibly exchanged between the bearing cavity 9 and the non-bearing cavity 10; when the wheel-leg robot needs to increase the height of the vehicle body 35, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are increased; when the wheel-leg robot needs to reduce the height of the vehicle body 35, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are reduced; the hydraulic oil pressure in the oil supplementing accumulator 13 is balanced with the non-bearing cavity 10; the hydraulic oil pressure in the high-pressure accumulator 16 is balanced with the bearing chamber 9. With the above structure, the present invention has a plurality of operation modes, and in the posture adjusting step, the height of the vehicle body 35 can be adjusted according to the road surface condition to be driven; in the passive vibration reduction step, the driving vibration reduction on the uphill and downhill road surfaces can be effectively realized, and the stability of the wheel-leg robot in the driving process is ensured; in the active gait step, the leg lifting and falling can be quickly realized, the obstacle can be crossed, and the stability of the vehicle body 35 can be ensured; the oil supplementing function of the oil supplementing energy accumulator 13 and the safety protection function of the first overflow valve 11 and the second overflow valve 12 enable the wheel leg robot to run more safely and reliably, and the service life is prolonged. The servo valve control cylinder is cancelled, no throttling loss is realized, and meanwhile, the buffer device with the absorption force is used for greatly improving the efficiency of joint driving, improving the effective energy utilization rate of the robot and prolonging the service life of the robot.

Example two:

see figures 4-6. A leg joint driving device of a wheel-legged robot comprises a hydraulic control system; the hydraulic control system comprises a hydraulic cylinder 1, a piston rod 2, a main oil way, a secondary oil way, a servo motor 7 and a hydraulic pump 8; a bearing cavity 9 and a non-bearing cavity 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates a bearing cavity 9 and a non-bearing cavity 10; the servo motor 7 is used for driving a hydraulic pump 8; the non-bearing cavity 10, the main oil way, the hydraulic pump 8, the secondary oil way and the bearing cavity 9 are communicated in sequence; the elongation of the piston rod 2 relative to the cylinder 1 changes with the change of the volume of hydraulic oil in the load bearing chamber 9 and the non-load bearing chamber 10. According to the structure, if the lines formed by the non-bearing cavity 10, the main oil way, the hydraulic pump 8, the secondary oil way and the bearing cavity 9 are communicated in sequence, the servo motor 7 rotates forwards, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are reduced; the servo motor 7 rotates reversely, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the piston rod 2 extends relative to the elongation of the hydraulic cylinder 1, and the size of an included angle between the car body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are increased. And a servo valve control cylinder is cancelled, so that no throttling loss is realized.

The hydraulic control system further includes a second high pressure accumulator 26; the second high-pressure accumulator 26 is communicated with the bearing cavity 9 through an oil path. As can be seen from the above structure, when the wheel 38 is rotated to contact the ground, the robot with wheel legs is driven to travel; when the wheel-legged robot runs on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is increased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the pressure of hydraulic oil in the bearing cavity 9 is increased, and the hydraulic oil with the increased pressure enters the second high-pressure energy accumulator 26 through an oil way, so that the pressure increase of the hydraulic oil in the bearing cavity 9 is buffered; when the wheel-leg robot runs on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the piston rod 2 is extended relative to the extension of the hydraulic cylinder 1, the pressure of hydraulic oil in the bearing cavity 9 is reduced, and the hydraulic oil in the second high-pressure energy accumulator 26 enters the bearing cavity 9 through an oil way for oil supplement, so that the pressure reduction of the hydraulic oil in the bearing cavity 9 is buffered; the second high-pressure accumulator 26 realizes vibration reduction in the running process of the wheel-leg robot, so that the stability of the vehicle body is ensured, vibration energy is absorbed, the influence on the wheel-leg robot is reduced, and the service life of the wheel-leg robot is prolonged.

The hydraulic control system further comprises a third solenoid valve 24; the main oil passage comprises a first oil passage 3 and a second oil passage 4; the secondary oil passages include a third oil passage 5 and a fourth oil passage 6; the third electromagnetic valve 24 is a two-position four-way electromagnetic switch valve; the third solenoid valve 24 includes a3 port, b3 port, c3 port and d3 port; two ends of the first oil path 3 are respectively communicated with an a3 port and a non-bearing cavity 10; two ends of the second oil path 4 are respectively communicated with a port b3 and the hydraulic pump 8; the two ends of the third oil path 5 are respectively communicated with a port c3 and a hydraulic pump 8; two ends of the fourth oil path 6 are respectively communicated with a port d3 and the bearing cavity 9; when the third electromagnetic valve 24 is at a potential, the ports except the port a3 and the port b3 are conducted, and the port c3 and the port d3 are conducted, and the rest ports are not conducted; when the third electromagnetic valve 24 is at a non-potential state, the port a3 and the port d3 are not communicated with each other. As can be seen from the above structure, when the third electromagnetic valve 24 is at a voltage, the ports a3 and b3 are connected, and the ports c3 and d3 are connected, but the other ports are not connected, that is, the ports a3, c3, d3 are not connected, the ports b3, c3, and d3 are not connected, and the lines formed by the non-load-bearing chamber 10, the first oil path 3, the second oil path 4, the hydraulic pump 8, the third oil path 5, the fourth oil path 6, and the load-bearing chamber 9 are already connected, so that 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 electromagnetic valve 24 is at a non-potential state, the port a3 and the port d3 are not communicated, and the rest ports are not communicated, and the bearing cavity 9 is communicated with the non-bearing cavity 10 through the first oil path 3 and the fourth oil path 6; the high-pressure hydraulic oil in the bearing cavity 9 can flow to the non-bearing cavity 10, so that the vehicle body 35 descends, the wheel leg robot is small when the power is lost, and the carrying is convenient.

When the third electromagnetic valve 24 is at a non-potential state, a second throttle valve 25 is arranged on a path through which the port a3 and the port d3 are communicated. As can be seen from the above structure, the second throttle valve 25 slows down the exchange speed between the hydraulic oil in the bearing cavity 9 and the non-bearing cavity 10, and the bearing cavity 9 is communicated with the non-bearing cavity 10 through the first oil path 3 and the fourth oil path 6; the high pressure hydraulic oil in the load chamber 9 flows to the non-load chamber 10 and throttles through the second throttle valve 25, so that the vehicle body 35 slowly descends.

The hydraulic cylinder 1 is an asymmetric hydraulic cylinder.

The hydraulic control system further comprises a controller and a force sensor; the force sensor, the third electromagnetic valve 24 and the servo motor 7 are respectively and electrically connected with the controller; the force sensor is used for monitoring a load signal of the piston rod 2 and transmitting the load signal to the controller; the controller is used for controlling the switch position of the third electromagnetic valve 24 and the rotating speed and the direction of the servo motor 7. According to the structure, when the wheel-leg robot runs on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is increased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the pressure of hydraulic oil in the bearing cavity 9 is increased, the hydraulic oil with the increased pressure enters the second high-pressure energy accumulator 26 through an oil way, the pressure of the hydraulic oil in the bearing cavity 9 is increased and buffered, and meanwhile, the force sensor monitors a 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 positively, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, so that the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened rapidly, and the size of an included angle between the car body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are reduced; when the wheel-leg robot runs on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the piston rod 2 extends relative to the elongation of the hydraulic cylinder 1, the pressure of hydraulic oil in the bearing cavity 9 is reduced, the hydraulic oil in the second high-pressure energy accumulator 26 enters the bearing cavity 9 through an oil way for oil supplement, so that the pressure reduction of the hydraulic oil in the bearing cavity 9 is buffered, meanwhile, the force sensor monitors a load signal that the load force of the piston rod 2 is reduced, and transmits the load signal to the controller; the controller controls the servo motor 7 to rotate reversely, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 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 size of an included angle between the car body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are increased.

A driving method of a leg joint driving device of a wheel-legged robot comprises an active vibration reduction step; the active vibration reduction step specifically comprises the following steps: when the wheel 38 rotates in a grounding way, the robot with wheel legs is driven to run; when the wheel-legged robot runs on a flat ground, the forced exchange of hydraulic oil is not performed between the bearing cavity 9 and the non-bearing cavity 10 for the moment; the load force born by the hydraulic cylinder 1 and the piston rod 2 is not fluctuated, the vehicle body 35 is not vibrated, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is kept unchanged, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are kept unchanged; when the wheel-leg robot runs on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is increased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the pressure of hydraulic oil in the bearing cavity 9 is increased, the hydraulic oil with the increased pressure enters the second high-pressure energy accumulator 26 through an oil path, the pressure increase of the hydraulic oil in the bearing cavity 9 is buffered, meanwhile, the hydraulic oil is forcibly exchanged between the bearing cavity 9 and the non-bearing cavity 10, the hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly shortened, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and; when the wheel-leg robot runs on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the pressure of hydraulic oil in the bearing cavity 9 is reduced, the hydraulic oil in the second high-pressure energy accumulator 26 enters the bearing cavity 9 through an oil way to supplement oil, so that the pressure reduction of the hydraulic oil in the bearing cavity 9 is buffered, meanwhile, hydraulic oil is forcibly exchanged between the bearing cavity 9 and the non-bearing cavity 10, the hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly extended, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh.

Also comprises an active gait step; the active gait steps are specifically as follows: when the wheel-leg robot runs and meets an obstacle, the bearing cavity 9 and the non-bearing cavity 10 are subjected to forced hydraulic oil exchange; when the robot with wheel legs lifts the legs, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, so that the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is quickly shortened, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are reduced; when the robot with wheel legs falls on legs, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, so that the piston rod 2 is rapidly extended relative to the extension amount of the hydraulic cylinder 1, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are increased.

Also comprises a posture adjusting step; the posture adjusting step specifically comprises the following steps: when the wheel-leg robot needs to adjust the height of the vehicle body 35, hydraulic oil is forcibly exchanged between the bearing cavity 9 and the non-bearing cavity 10; when the wheel-leg robot needs to increase the height of the vehicle body 35, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are increased; when the wheel-leg robot needs to reduce the height of the vehicle body 35, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are reduced.

Also comprises a power-off step; the power-off steps are as follows: when the wheel-leg robot loses power, hydraulic oil is freely exchanged between the bearing cavity 9 and the non-bearing cavity 10; the high-pressure hydraulic oil in the bearing cavity 9 flows to the non-bearing cavity 10, so that the vehicle body 35 slowly descends; at the same time, the second high-pressure accumulator 26 damps vibrations by exchanging hydraulic oil with the support chamber 9. With the above structure, the present invention has a plurality of operation modes, and in the posture adjusting step, the height of the vehicle body 35 can be adjusted according to the road surface condition to be driven; in the active vibration reduction step, the driving vibration reduction on the uphill and downhill road surfaces can be effectively realized, and the stability of the wheel-leg robot in the driving process is ensured; in the active gait step, the leg lifting and falling can be quickly realized, the obstacle 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 ensure that the wheel-leg robot runs more safely and reliably, and the service life is prolonged. The servo valve control cylinder is cancelled, no throttling loss is realized, and meanwhile, the buffer device with the absorption force is used for greatly improving the efficiency of the joint driver, improving the effective energy utilization rate of the robot and prolonging the service life of the joint driver of the robot.

Example three:

see figures 7-9. A leg joint driving device of a wheel-legged robot comprises a hydraulic control system; the hydraulic control system comprises a hydraulic cylinder 1, a piston rod 2, a main oil way, a secondary oil way, a servo motor 7 and a hydraulic pump 8; a bearing cavity 9 and a non-bearing cavity 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates a bearing cavity 9 and a non-bearing cavity 10; the servo motor 7 is used for driving a hydraulic pump 8; the non-bearing cavity 10, the main oil way, the hydraulic pump 8, the secondary oil way and the bearing cavity 9 are communicated in sequence; the elongation of the piston rod 2 relative to the cylinder 1 changes with the change of the volume of hydraulic oil in the load bearing chamber 9 and the non-load bearing chamber 10. According to the structure, if the lines formed by the non-bearing cavity 10, the main oil way, the hydraulic pump 8, the secondary oil way and the bearing cavity 9 are communicated in sequence, the servo motor 7 rotates forwards, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are reduced; the servo motor 7 rotates reversely, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the piston rod 2 extends relative to the elongation of the hydraulic cylinder 1, and the size of an included angle between the car body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are increased. And a servo valve control cylinder is cancelled, so that no throttling loss is realized.

The hydraulic control system also comprises a motor gear control system; a hydraulic control system controls the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 or controls the size of an included angle between the vehicle body 35 and the thigh 36 through a motor gear control system; the other hydraulic control system controls the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 or controls the size of the included angle between the thigh 36 and the shank 37 through a motor gear control system. According to the structure, the size of the included angle between the vehicle body 35 and the thigh 36 can be controlled through the motor gear control system, the motor gear control system adopts the motor and the gear driving assembly to drive the vehicle body 35 and the thigh 36 to rotate relatively, when a large load is borne between the vehicle body 35 and the thigh 36, the hydraulic cylinder 1 and the piston rod 2 are selected to change the included angle between the vehicle body 35 and the thigh 36, and when a small load or no load is borne between the vehicle body 35 and the thigh 36, the motor gear control system is selected to change the included angle between the vehicle body 35 and the thigh 36, so that the selectable driving mode is realized, the system power is saved, the transmission efficiency is high, and the energy utilization rate is high; in the hydraulic control system corresponding to the thigh 36 and the calf 37, two ends of a matching component of the hydraulic cylinder 1 and the piston rod 2 are respectively hinged with the thigh 36 and the calf 37, so that the extension of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the included angle between the thigh 36 and the calf 37 is reduced, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the included angle between the thigh 36 and the calf 37 is increased, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is kept unchanged, and the included angle between the thigh 36 and the calf 37 is kept unchanged; the size of an included angle between the thigh 36 and the shank 37 can be controlled through a motor gear control system, the motor gear control system adopts a motor and a gear driving assembly to drive the thigh 36 and the shank 37 to rotate relatively, when a large load is borne between the thigh 36 and the shank 37, the included angle between the thigh 36 and the shank 37 is changed by selecting the hydraulic cylinder 1 and the piston rod 2, and when a small load or no load is borne between the thigh 36 and the shank 37, the included angle between the thigh 36 and the shank 37 is changed by selecting the motor gear control system, so that the selectable driving mode is realized, the system power is saved, the transmission efficiency is high, and the energy utilization rate is high; therefore, the two hydraulic control systems have two driving modes to control the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37, so that the wheel 38 moves forwards, backwards, upwards and downwards relative to the vehicle body 35 to be adjusted. A bearing cavity 9 and a non-bearing cavity 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates a bearing cavity 9 and a non-bearing cavity 10; the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is changed along with the change of the volume of the hydraulic oil in the bearing cavity 9 and the non-bearing cavity 10; the hydraulic oil capacity of the bearing cavity 9 is increased, the hydraulic oil capacity of the non-bearing cavity 10 is decreased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the hydraulic oil capacity of the bearing cavity 9 is decreased, the hydraulic oil capacity of the non-bearing cavity 10 is increased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the hydraulic oil capacities of the bearing cavity 9 and the non-bearing cavity 10 are kept unchanged, and the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is kept unchanged. According to the invention, the double-drive structure simultaneously selects a proper drive mode to drive the joint in the hydraulic actuator with high power density ratio and electric transmission according to the working condition characteristics of the wheel-leg robot, so that higher space trajectory tracking precision is achieved, the efficiency of a joint driver is improved, and the effective energy utilization rate of the robot is improved.

The hydraulic control system further comprises a fourth solenoid valve 30; the main oil passage comprises a first oil passage 3 and a second oil passage 4; the secondary oil passages include a third oil passage 5 and a fourth oil passage 6; the fourth electromagnetic valve 30 is a two-position two-way electromagnetic switch valve; the fourth solenoid valve 30 includes a port 4 and a port b 4; the non-bearing cavity 10, the first oil way 3, the second oil way 4, the hydraulic pump 8, the third oil way 5, the fourth oil way 6 and the bearing cavity 9 are communicated in sequence; the first oil passage 3 and the second oil passage 4 are communicated with a port a 4; the third oil passage 5 and the fourth oil passage 6 are communicated with a port b 4; when the fourth electromagnetic valve 30 is at a potential, the port a4 and the port b4 are not conducted; when the fourth solenoid valve 30 is at a loss of potential, the port a4 and the port b4 are connected. As can be seen from the above structure, the fourth solenoid valve 30 is at a high potential, and the ports a4 and b4 are not conducted; the non-bearing cavity 10, the first oil way 3, the second oil way 4, the hydraulic pump 8, the third oil way 5, the fourth oil way 6 and the bearing cavity 9 are communicated; the hydraulic pump 8 can change the flow direction of the hydraulic oil in the bearing cavity 9 and the non-bearing cavity 10; when the wheel-leg robot is powered off, the port a4 and the port b4 are communicated when the fourth electromagnetic valve 30 is in a power-off state; the non-bearing cavity 10 is communicated with the bearing cavity 9 through the first oil way 3 and the fourth oil way 6; the servo motor 7 and the hydraulic pump 8 are in a non-working state; when power is lost, high-pressure hydraulic oil in the bearing cavity 9 flows to the non-bearing cavity 10, so that the vehicle body 35 descends, the wheel leg robot is small, and the wheel leg robot is convenient to carry; when the motor gear control system is used, high-pressure hydraulic oil in the bearing cavity 9 flows to the non-bearing cavity 10, so that effective adjustment of electric drive is facilitated.

The motor gear control system comprises a driving motor 31, a speed reducer 32, a rotation gear 33 and a fixed gear 34; the rotation gear 33 is meshed with the fixed gear 34; the driving motor 31 is used for driving the reducer 32 to drive the rotation gear 33 to rotate; when the rotation gear 33 rotates, the rotation gear 33 relatively rotates around the fixed gear 34. According to the structure, in the motor gear control system of the hydraulic control system corresponding to the space between the vehicle body 35 and the thigh 36, the fixed gear 34 is fixed with the hinge shaft between the vehicle body 35 and the thigh 36, the hinge shaft is fixed with the vehicle body 35, the rotation 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 is fixed with the rotation gear 33, when the driving motor 31 is used for driving the speed reducer 32 to drive the rotation gear 33 to rotate, the rotation gear 33 relatively rotates around the fixed gear 34, the thigh 36 swings relative to the vehicle body 35, and the included angle between the vehicle body 35 and the thigh 36 changes; in the motor-gear control system of the hydraulic control system corresponding to the thigh 36 and the shank 37, a fixed gear 34 is fixed with a hinge shaft between the thigh 36 and the shank 37, the hinge shaft is fixed with the shank 37, a rotation gear 33 is rotatably arranged at the other end of the thigh 36 and meshed with the fixed gear 34, a speed reducer 32 is fixed on the thigh 36, an output shaft of the speed reducer 32 is fixed with the rotation gear 33, when a driving motor 31 is used for driving the speed reducer 32 to drive the rotation gear 33 to rotate, the rotation gear 33 rotates around the fixed gear 34 relatively, the shank 37 swings relative to the thigh 36, and an included angle between the thigh 36 and the shank 37 changes.

The hydraulic control system further comprises an oil-supplementing accumulator 13; and the oil supplementing accumulator 13 is communicated with an oil drainage port of the hydraulic pump 8. According to the structure, the oil supplementing energy accumulator 13 is communicated with the oil drainage port of the hydraulic pump 8, and the oil supplementing energy accumulator 13 can collect hydraulic oil leaked from the hydraulic pump 8, so that oil consumption is reduced.

The hydraulic control system further comprises a first check valve 14 and a second check valve 15; the outlet of the oil supplementing accumulator 13 is communicated with the inlet of a first one-way valve 14 and the inlet of a second one-way valve 15; the outlet of the first one-way valve 14 is communicated with a main oil way; the outlet of the second check valve 15 is communicated with a secondary oil path. According to the structure, if the pressure of the hydraulic oil in the bearing cavity 9 is too low, the oil supplementing energy accumulator 13 supplements oil to the hydraulic pump 8 through the second one-way valve 15, so that the hydraulic pump 8 is ensured to continuously suck the hydraulic oil; if the pressure of the hydraulic oil in the non-bearing cavity 10 is too low, the oil supplementing energy accumulator 13 supplements oil to the hydraulic pump 8 through the first one-way valve 14, so that the hydraulic pump 8 is ensured to continuously suck the hydraulic oil; thereby improving the energy utilization rate and the reaction speed.

The hydraulic control system further includes a second controller and a second force sensor; the second force sensor, the fourth electromagnetic valve 30 and the servo motor 7 are respectively and electrically connected with a second controller; the second force sensor is used for monitoring a load signal of the piston rod 2 and transmitting the load signal to the second controller; the second controller is used for controlling the switching position of the fourth electromagnetic valve 30, the rotating speed and the direction of the driving motor 31 and the servo motor 7. According to the structure, when the wheel-leg robot runs on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is increased, the second force sensor monitors 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 positively, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, so that the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened rapidly, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are reduced; when the wheel-legged robot runs on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, and the second force sensor monitors a load signal of the piston rod 2 with the reduced load force and transmits the load signal to the second controller; the servo motor 7 is controlled by the second controller to rotate reversely, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, so that the piston rod 2 extends rapidly relative to the extension amount of the hydraulic cylinder 1, and the size of an included angle between the car body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are increased.

A driving method of a leg joint driving device of a wheel-legged robot comprises an active vibration reduction step; the active vibration reduction step specifically comprises the following steps: when the wheel 38 rotates in a grounding way, the robot with wheel legs is driven to run; when the wheel-legged robot runs on a flat ground, the forced exchange of hydraulic oil is not performed between the bearing cavity 9 and the non-bearing cavity 10 for the moment; the load force born by the hydraulic cylinder 1 and the piston rod 2 is not fluctuated, the vehicle body 35 is not vibrated, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is kept unchanged, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are kept unchanged; when the wheel-leg robot runs on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is increased, hydraulic oil is forcibly exchanged between the bearing cavity 9 and the non-bearing cavity 10, the hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 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 size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are both reduced; when the wheel-leg robot runs on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, hydraulic oil is forcibly exchanged between the bearing cavity 9 and the non-bearing cavity 10, the hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the piston rod 2 is enabled to be rapidly extended relative to the extension amount of the hydraulic cylinder 1, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are both increased.

Also comprises an active gait step; the active gait steps are specifically as follows: when the wheel-leg robot runs and meets an obstacle, hydraulic oil is freely exchanged between the bearing cavity 9 and the non-bearing cavity 10; when the wheel-legged robot lifts the legs, the motor and gear control systems corresponding to the two hydraulic control systems respectively reduce the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37; when the robot with wheel legs falls on the legs, the motor and gear control systems corresponding to the two hydraulic control systems respectively enable the size of an included angle between the robot body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 to be increased.

Also comprises a posture adjusting step; the posture adjusting step specifically comprises the following steps: when the wheel-leg robot needs to adjust the height of the vehicle body 35, the bearing cavity 9 and the non-bearing cavity 10 are subjected to hydraulic oil forced exchange; when the wheel-leg robot needs to increase the height of the vehicle body 35, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are increased; when the wheel-leg robot needs to reduce the height of the vehicle body 35, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are reduced.

Also comprises a power-off step; the power-off steps are as follows: when the wheel-leg robot loses power, hydraulic oil is freely exchanged between the bearing cavity 9 and the non-bearing cavity 10; the high pressure hydraulic oil in the load chamber 9 flows to the non-load chamber 10, and the vehicle body 35 is lowered. With the above structure, the present invention has a plurality of operation modes, and in the posture adjusting step, the height of the vehicle body 35 can be adjusted according to the road surface condition to be driven; in the active vibration reduction step, the driving vibration reduction on the uphill and downhill road surfaces can be effectively realized, and the stability of the wheel-leg robot in the driving process is ensured; in the active gait step, the leg lifting and falling can be quickly realized, the obstacle can be crossed, and the stability of the vehicle body 35 can be ensured; the oil supplementing function of the oil supplementing energy accumulator 13 and the safety protection function of the first overflow valve 11 and the second overflow valve 12 enable the wheel leg robot to run more safely and reliably, and the service life is prolonged. And a servo valve control cylinder is cancelled, so that no throttling loss is realized. According to the invention, the double-drive structure simultaneously selects a proper drive mode to drive the joint in the hydraulic actuator with high power density ratio and electric transmission according to the working condition characteristics of the wheel-leg robot, so that higher space trajectory tracking precision is achieved, the efficiency of a joint driver is improved, and the effective energy utilization rate of the robot is improved.

Example four:

see figures 4, 5, 10. A leg joint driving device of a wheel-legged robot comprises a hydraulic control system; the hydraulic control system comprises a hydraulic cylinder 1, a piston rod 2, a main oil way, a secondary oil way, a servo motor 7 and a hydraulic pump 8; a bearing cavity 9 and a non-bearing cavity 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates a bearing cavity 9 and a non-bearing cavity 10; the servo motor 7 is used for driving a hydraulic pump 8; the non-bearing cavity 10, the main oil way, the hydraulic pump 8, the secondary oil way and the bearing cavity 9 are communicated in sequence; the elongation of the piston rod 2 relative to the cylinder 1 changes with the change of the volume of hydraulic oil in the load bearing chamber 9 and the non-load bearing chamber 10. According to the structure, if the lines formed by the non-bearing cavity 10, the main oil way, the hydraulic pump 8, the secondary oil way and the bearing cavity 9 are communicated in sequence, the servo motor 7 rotates forwards, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are reduced; the servo motor 7 rotates reversely, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the piston rod 2 extends relative to the elongation of the hydraulic cylinder 1, and the size of an included angle between the car body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are increased. And a servo valve control cylinder is cancelled, so that no throttling loss is realized.

A bearing cavity 9, a non-bearing cavity 10 and a spring 29 are arranged in the hydraulic cylinder 1; said spring 29 is used to give the rod part of the piston rod 2 a tendency to extend out of the hydraulic cylinder 1. As can be seen from the above structure, when the wheel 38 is rotated to contact the ground, the robot with wheel legs is driven to travel; when the robot with wheel legs runs on a flat ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is not fluctuated, the vehicle body 35 is not vibrated, the spring 29 stably bears the pressure of the piston rod 2, and the pressure borne by hydraulic oil in the bearing cavity 9 is reduced; when the wheel-legged robot runs on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is increased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the pressure of hydraulic oil in the bearing cavity 9 is increased, and the compression amount of the spring 29 is increased, so that the pressure increase of the hydraulic oil in the bearing cavity 9 is buffered; when the wheel-leg robot runs on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the piston rod 2 extends relative to the extension of the hydraulic cylinder 1, the pressure of hydraulic oil in the bearing cavity 9 is reduced, the compression amount 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 in the running process of the wheel-leg robot, so that the stability of the vehicle body is ensured, vibration energy is absorbed, the influence on the wheel-leg robot is reduced, and the service life of the wheel-leg robot is prolonged. The input power requirement of the joint driving device is reduced by skillfully utilizing the spring, the requirement on input energy is reduced, the efficiency of the joint driver is greatly improved, the effective energy utilization rate of the robot is improved, and the cruising time of the robot is prolonged.

A guide rod 27 is arranged in the hydraulic cylinder 1; the piston rod 2 is hollow inside and sleeved outside the guide rod 27; the bearing chamber 9 is positioned on top of the guide rod 27 and is surrounded by the rod part of the piston rod 2; a conduction path 28 is arranged in the guide rod 27; the conducting path 28 is communicated with the bearing cavity 9 and the secondary oil path; a spring 29 is sleeved outside 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 sleeved outside the guide rod 27, and the guide rod 27 guides the extending and shortening movement of the piston rod 2 relative to the hydraulic cylinder 1; a conduction path 28 is arranged in the guide rod 27; the conducting path 28 is communicated with the bearing cavity 9 and the secondary oil path; when the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the pressure of hydraulic oil in the bearing cavity 9 is increased, the pressure of a plug part of the piston rod 2 borne by the spring 29 is increased, the compression amount of the spring 29 is increased, and the hydraulic oil in the bearing cavity 9 flows to a secondary oil way through the conducting path 28 and is sucked to the non-bearing cavity 10 by the hydraulic pump 8; when the piston rod 2 extends relative to the extension of the hydraulic cylinder 1, the pressure of the hydraulic oil in the bearing cavity 9 is reduced, the pressure of the plug part of the piston rod 2 borne by the spring 29 is reduced, the compression amount of the spring 29 is reduced, the rod part of the auxiliary piston rod 2 extends out of the hydraulic cylinder 1, the hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, and the piston rod 2 extends rapidly relative to the extension of the hydraulic cylinder 1. A spring 29 is externally fitted to the guide rod 27 such that the spring 29 is always compressed between the plug portion of the piston rod 2 and the bottom portion of the hydraulic cylinder 1.

The hydraulic control system further comprises a third solenoid valve 24; the main oil passage comprises a first oil passage 3 and a second oil passage 4; the secondary oil passages include a third oil passage 5 and a fourth oil passage 6; the third electromagnetic valve 24 is a two-position four-way electromagnetic switch valve; the third solenoid valve 24 includes a3 port, b3 port, c3 port and d3 port; two ends of the first oil path 3 are respectively communicated with an a3 port and a non-bearing cavity 10; two ends of the second oil path 4 are respectively communicated with a port b3 and the hydraulic pump 8; the two ends of the third oil path 5 are respectively communicated with a port c3 and a hydraulic pump 8; the two ends of the fourth oil path 6 are respectively communicated with a port d3 and a conduction path 28; when the third electromagnetic valve 24 is at a potential, the ports except the port a3 and the port b3 are conducted, and the port c3 and the port d3 are conducted, and the rest ports are not conducted; when the third electromagnetic valve 24 is at a non-potential state, the port a3 and the port d3 are not communicated with each other. As can be seen from the above structure, when the third electromagnetic valve 24 is at a voltage, the ports a3 and b3 are connected, and the ports c3 and d3 are connected, but the other ports are not connected, that is, the ports a3, c3, d3 are not connected, the ports b3, c3, and d3 are not connected, and the lines formed by the non-load-bearing chamber 10, the first oil path 3, the second oil path 4, the hydraulic pump 8, the third oil path 5, the fourth oil path 6, and the load-bearing chamber 9 are already connected, so that 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 electromagnetic valve 24 is at a non-potential state, the port a3 and the port d3 are not communicated, and the rest ports are not communicated, and the bearing cavity 9 is communicated with the non-bearing cavity 10 through the first oil path 3 and the fourth oil path 6; the high-pressure hydraulic oil in the bearing cavity 9 can flow to the non-bearing cavity 10, so that the vehicle body 35 descends, the wheel leg robot is small when the power is lost, and the carrying is convenient.

The hydraulic control system further comprises a controller and a force sensor; the force sensor, the third electromagnetic valve 24 and the servo motor 7 are respectively and electrically connected with the controller; the force sensor is used for monitoring a load signal of the piston rod 2 and transmitting the load signal to the controller; the controller is used for controlling the switch position of the third electromagnetic valve 24 and the rotating speed and the direction of the servo motor 7. According to the structure, when the wheel-leg robot runs on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is increased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the pressure of hydraulic oil in the bearing cavity 9 is increased, the compression amount of the spring 29 is increased, the pressure increase of the hydraulic oil in the bearing cavity 9 is buffered, and meanwhile, the force sensor monitors a 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 positively, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, so that the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened rapidly, and the size of an included angle between the car body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are reduced; when the wheel-leg robot runs on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the piston rod 2 extends relative to the extension amount of the hydraulic cylinder 1, the pressure of hydraulic oil in the bearing cavity 9 is reduced, the compression amount of the spring 29 is reduced, the rod part of the auxiliary piston rod 2 extends out of the hydraulic cylinder 1, and meanwhile, the force sensor monitors a load signal that the load force of the piston rod 2 is reduced and transmits the load signal to the controller; the controller controls the servo motor 7 to rotate reversely, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 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 size of an included angle between the car body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37 are increased.

A driving method of a leg joint driving device of a wheel-legged robot comprises an active vibration reduction step; the active vibration reduction step specifically comprises the following steps: when the wheel 38 rotates in a grounding way, the robot with wheel legs is driven to run; when the wheel-legged robot runs on a flat ground, the forced exchange of hydraulic oil is not performed between the bearing cavity 9 and the non-bearing cavity 10 for the moment; the load force born by the hydraulic cylinder 1 and the piston rod 2 is not fluctuated, the vehicle body 35 is not vibrated, the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 is kept unchanged, the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are kept unchanged, and the spring 29 bears the pressure of the piston rod 2; when the wheel-leg robot runs on an uphill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is increased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the pressure of hydraulic oil in the bearing cavity 9 is increased, the compression amount of the spring 29 is increased, the pressure increase of the hydraulic oil in the bearing cavity 9 is buffered, meanwhile, the hydraulic oil is forcibly exchanged between the bearing cavity 9 and the non-bearing cavity 10, the hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly shortened, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are; when the wheel-leg robot runs on a downhill ground, the load force borne by the hydraulic cylinder 1 and the piston rod 2 is reduced, the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the pressure of hydraulic oil in the bearing cavity 9 is reduced, the compression amount of the spring 29 is reduced, the rod part of the auxiliary piston rod 2 extends out of the hydraulic cylinder 1, meanwhile, hydraulic oil is forcibly exchanged between the bearing cavity 9 and the non-bearing cavity 10, the hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the extension amount of the piston rod 2 relative to the hydraulic cylinder 1 is rapidly extended, and the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36.

Also comprises a posture adjusting step; the posture adjusting step specifically comprises the following steps: when the wheel-leg robot needs to adjust the height of the vehicle body 35, hydraulic oil is forcibly exchanged between the bearing cavity 9 and the non-bearing cavity 10; when the wheel-leg robot needs to increase the height of the vehicle body 35, hydraulic oil in the non-bearing cavity 10 is sucked to the bearing cavity 9 by the hydraulic pump 8, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are increased; when the wheel-leg robot needs to reduce the height of the vehicle body 35, hydraulic oil in the bearing cavity 9 is sucked to the non-bearing cavity 10 by the hydraulic pump 8, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, and the size of an included angle between the vehicle body 35 and a thigh 36 and the size of an included angle between the thigh 36 and a shank 37 are reduced; the spring 29 is always subjected to the pressure of the piston rod 2.

Also comprises a power-off step; the power-off steps are as follows: when the wheel-leg robot loses power, hydraulic oil is freely exchanged between the bearing cavity 9 and the non-bearing cavity 10; the high-pressure hydraulic oil in the bearing cavity 9 flows to the non-bearing cavity 10, so that the vehicle body 35 slowly descends; at the same time, the spring 29 damps the vibrations. With the above structure, the present invention has a plurality of operation modes, and in the posture adjusting step, the height of the vehicle body 35 can be adjusted according to the road surface condition to be driven; in the active vibration reduction step, the driving vibration reduction on the uphill and downhill road surfaces can be effectively realized, and the stability of the wheel-leg robot in the driving process is ensured; in the active gait step, the leg lifting and falling can be quickly realized, the obstacle 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 ensure that the robot with wheel legs runs more safely and reliably, and the service life is prolonged. The invention cancels a servo valve control cylinder, realizes no throttling loss, simultaneously skillfully utilizes the spring to reduce the input power requirement of the joint driving device during vibration reduction in the driving process, reduces the requirement on input energy, greatly improves the efficiency of a joint driver, improves the effective energy utilization rate of the robot, and prolongs the cruising time of the robot.

Example five:

see figures 1-10. A wheel-leg robot includes a vehicle body 35, thighs 36, calves 37, wheels 38, and two hydraulic control systems; the hydraulic control system adopts the hydraulic control system of the leg joint driving device of the wheel-leg robot in the embodiment; one end of the thigh 36 is hinged with the vehicle body 35, and the other end of the thigh 36 is hinged with 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 size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37. As can be seen from the above structure, the vehicle body 35 is a body part of the wheel-leg robot, and the traveling state of the vehicle body 35 is mainly performed by the legs of the wheel-leg robot, which may have one pair or two pairs of legs, i.e., a combination of the thigh 36, the calf 37, and the wheel 38; one end of the thigh 36 is hinged with the vehicle body 35, and the hinge can be hinged directly through a rotating shaft or indirectly through a hip joint; the other end of the thigh 36 is hinged with one end of the shank 37, and the hinge joint can be directly hinged through a rotating shaft or indirectly hinged through a knee joint; the other end of the shank 37 is provided with a wheel 38, and the rotation of the wheel 38 leads the leg to drive the vehicle body 35 to move forwards or backwards; one leg is provided with two hydraulic control systems; a hydraulic control system controls the size of the included angle between the vehicle body 35 and the thigh 36, for example, the included angle is kept unchanged, and is increased or decreased; another hydraulic control system controls the size of the included angle between the thigh 36 and the shank 37, for example, the included angle is kept unchanged, and is increased or decreased; the two hydraulic control systems respectively control the size of an included angle between the vehicle body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37, so that the wheels 38 can move forwards, backwards, upwards and downwards relative to the vehicle body 35 to be adjusted; in the hydraulic control system corresponding to the car body 35 and the thigh 36, two ends of a matching assembly of the hydraulic cylinder 1 and the piston rod 2 are respectively hinged with the car body 35 and the thigh 36, so that the extension of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the included angle between the car body 35 and the thigh 36 is reduced, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the included angle between the car body 35 and the thigh 36 is increased, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is kept unchanged, and the included angle between the car body 35 and the thigh 36 is kept unchanged; in the hydraulic control system corresponding to the thigh 36 and the calf 37, two ends of a matching component of the hydraulic cylinder 1 and the piston rod 2 are respectively hinged with the thigh 36 and the calf 37, so that the extension of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the included angle between the thigh 36 and the calf 37 is reduced, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the included angle between the thigh 36 and the calf 37 is increased, the extension of the piston rod 2 relative to the hydraulic cylinder 1 is kept unchanged, and the included angle between the thigh 36 and the calf 37 is kept unchanged; therefore, the two hydraulic control systems respectively control the size of an included angle between the car body 35 and the thigh 36 and the size of an included angle between the thigh 36 and the shank 37, so that the wheel 38 moves forwards, backwards, upwards and downwards relative to the car body 35 to be adjusted; a bearing cavity 9 and a non-bearing cavity 10 are arranged in the hydraulic cylinder 1; the piston rod 2 separates a bearing cavity 9 and a non-bearing cavity 10; the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is changed along with the change of the volume of the hydraulic oil in the bearing cavity 9 and the non-bearing cavity 10; the hydraulic oil capacity of the bearing cavity 9 is increased, the hydraulic oil capacity of the non-bearing cavity 10 is decreased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is extended, the hydraulic oil capacity of the bearing cavity 9 is decreased, the hydraulic oil capacity of the non-bearing cavity 10 is increased, the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is shortened, the hydraulic oil capacities of the bearing cavity 9 and the non-bearing cavity 10 are kept unchanged, and the elongation of the piston rod 2 relative to the hydraulic cylinder 1 is kept unchanged.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. The utility model provides a wheel leg robot shank joint drive arrangement which characterized in that: comprises a hydraulic control system; the hydraulic control system comprises a hydraulic cylinder (1), a piston rod (2), a main oil way, a secondary oil way, a servo motor (7) and a hydraulic pump (8); a bearing cavity (9) and a non-bearing cavity (10) are arranged in the hydraulic cylinder (1); the piston rod (2) separates a bearing cavity (9) and a non-bearing cavity (10); the servo motor (7) is used for driving a hydraulic pump (8); the non-bearing cavity (10), the main oil way, the hydraulic pump (8), the secondary oil way and the bearing cavity (9) are communicated in sequence; the elongation of the piston rod (2) relative to the hydraulic cylinder (1) is changed along with the change of the volume of the hydraulic oil in the bearing cavity (9) and the non-bearing cavity (10).

2. The leg joint driving apparatus for a robot wheel according to claim 1, wherein: the hydraulic control system also comprises a first overflow valve (11) and a second overflow valve (12); the inlet of the first overflow valve (11) is communicated with a main oil way; the outlet of the first overflow valve (11) is communicated with a secondary oil way; an inlet of the second overflow valve (12) is communicated with a secondary oil way; and the outlet of the second overflow valve (12) is communicated with a main oil way.

3. The leg joint driving apparatus for a robot wheel according to claim 1, wherein: the hydraulic control system further comprises an oil-supplementing accumulator (13); the hydraulic control system further comprises a first check valve (14) and a second check valve (15); an outlet of the oil supplementing accumulator (13) is communicated with an inlet of a first one-way valve (14) and an inlet of a second one-way valve (15); an outlet of the first check valve (14) is communicated with a main oil way; and an outlet of the second one-way valve (15) is communicated with a secondary oil way.

4. The leg joint driving apparatus of a wheeled legged robot as claimed in claim 3, characterized in that: the hydraulic control system also comprises a high-pressure accumulator (16), a high-pressure oil way and a low-pressure oil way; the outlet of the oil supplementing accumulator (13) is communicated with the non-bearing cavity (10) through a low-pressure oil way; the outlet of the high-pressure accumulator (16) is communicated with the bearing cavity (9) through a high-pressure oil way.

5. The leg joint driving apparatus of a wheeled legged robot as claimed in claim 4, characterized in that: the hydraulic control system further comprises a first solenoid valve (22) and a second solenoid valve (21); the low-pressure oil passage comprises a fifth oil passage (17) and a sixth oil passage (18); the high-pressure oil passage comprises a seventh oil passage (19) and an eighth oil passage (20); the second electromagnetic valve (21) is a two-position four-way electromagnetic switch valve; the second solenoid valve (21) comprises a2 port, b2 port, c2 port and d2 port; two ends of the fifth oil path (17) are respectively communicated with an a2 port and an oil supplementing accumulator (13); two ends of the sixth oil path (18) are respectively communicated with a port b2 and the non-bearing cavity (10); two ends of the seventh oil path (19) are respectively communicated with a port c2 and a high-pressure accumulator (16); two ends of the eighth oil path (20) are respectively communicated with a port d2 and a bearing cavity (9); when the second electromagnetic valve (21) is at a non-potential state, the ports except the port a2 and the port b2 are conducted, and the port c2 and the port d2 are conducted, and the rest ports are not conducted; when the second electromagnetic valve (21) is at a potential, all the ports are not communicated; the main oil way comprises a first oil way (3) and a second oil way (4); the secondary oil way comprises a third oil way (5) and a fourth oil way (6); the first electromagnetic valve (22) is a two-position four-way electromagnetic switch valve; the first solenoid valve (22) includes a1 port, b1 port, c1 port and d1 port; two ends of the first oil path (3) are respectively communicated with an a1 port and a non-bearing cavity (10); two ends of the second oil path (4) are respectively communicated with a port b1 and the hydraulic pump (8); two ends of the third oil path (5) are respectively communicated with a port c1 and a hydraulic pump (8); two ends of the fourth oil path (6) are respectively communicated with a d1 port and a bearing cavity (9); when the first electromagnetic valve (22) is at a potential, the ports except the port a1 and the port b1 are conducted, and the port c1 and the port d1 are conducted, and the rest ports are not conducted; when the first electromagnetic valve (22) is at a loss potential, all the ports are not conducted.

6. The leg joint driving apparatus for a robot wheel according to claim 1, wherein: the hydraulic control system further comprises a third solenoid valve (24); the main oil way comprises a first oil way (3) and a second oil way (4); the secondary oil way comprises a third oil way (5) and a fourth oil way (6); the third electromagnetic valve (24) is a two-position four-way electromagnetic switch valve; the third solenoid valve (24) comprises a3 port, b3 port, c3 port and d3 port; two ends of the first oil path (3) are respectively communicated with an a3 port and a non-bearing cavity (10); two ends of the second oil path (4) are respectively communicated with a port b3 and the hydraulic pump (8); two ends of the third oil path (5) are respectively communicated with a port c3 and a hydraulic pump (8); two ends of the fourth oil path (6) are respectively communicated with a d3 port and a bearing cavity (9); when the third electromagnetic valve (24) is at an obtained potential, the ports except the port a3 and the port b3 are conducted, and the port c3 and the port d3 are conducted, and the rest ports are not conducted; when the third electromagnetic valve (24) is at a non-potential state, the port a3 and the port d3 are not communicated, and the other ports are not communicated.

7. The leg joint driving apparatus of a wheeled legged robot as claimed in claim 6, characterized in that: the hydraulic control system further comprises a second high pressure accumulator (26); the second high-pressure accumulator (26) is communicated with the bearing cavity (9) through an oil way.

8. The leg joint driving apparatus of a wheeled legged robot as claimed in claim 6, characterized in that: the hydraulic control system further comprises a controller and a force sensor; the force sensor, the third electromagnetic valve (24) and the servo motor (7) are respectively and electrically connected with the controller; the force sensor is used for monitoring a load signal of the piston rod (2) and transmitting the load signal to the controller; the controller is used for controlling the on-off position of the third electromagnetic valve (24) and the rotating speed and the direction of the servo motor (7).

9. The leg joint driving apparatus of a wheeled legged robot as claimed in claim 6, characterized in that: a guide rod (27) is arranged in the hydraulic cylinder (1); the piston rod (2) is hollow inside and sleeved outside the guide rod (27); the bearing cavity (9) is positioned at the top of the guide rod (27) and is surrounded by the rod part of the piston rod (2); a conduction path (28) is arranged in the guide rod (27); the conduction path (28) is communicated with the bearing cavity (9) and the fourth oil path (6); a spring (29) is sleeved outside the guide rod (27); the spring (29) is compressed between the plug part of the piston rod (2) and the bottom of the hydraulic cylinder (1); the non-bearing cavity (10) is positioned between the rod part of the piston rod (2) and the hydraulic cylinder (1).

10. The leg joint driving apparatus for a robot wheel according to claim 1, wherein: the hydraulic control system also comprises a fourth electromagnetic valve (30) and a motor gear control system; the main oil way comprises a first oil way (3) and a second oil way (4); the secondary oil way comprises a third oil way (5) and a fourth oil way (6); the fourth electromagnetic valve (30) is a two-position two-way electromagnetic switch valve; the fourth solenoid valve (30) includes a port 4 and a port b 4; the non-bearing cavity (10), the first oil way (3), the second oil way (4), the hydraulic pump (8), the third oil way (5), the fourth oil way (6) and the bearing cavity (9) are communicated in sequence; the first oil passage (3) and the second oil passage (4) are communicated with a port a 4; the third oil passage (5) and the fourth oil passage (6) are communicated with a port b 4; when the fourth electromagnetic valve (30) is at a potential, the port a4 and the port b4 are not conducted; when the fourth electromagnetic valve (30) is at a loss potential, the port a4 and the port b4 are conducted; the motor gear control system comprises a driving motor (31), a speed reducer (32), a rotation gear (33) and a fixed gear (34); the rotation gear (33) is meshed with the fixed gear (34); the driving motor (31) is used for driving the speed reducer (32) to drive the rotation gear (33) to rotate; when the rotation gear (33) rotates, the rotation gear (33) rotates relatively around the fixed gear (34).

11. A wheel-legged robot, characterized in that: comprises a vehicle body (35), thighs (36), shanks (37), wheels (38) and two hydraulic control systems; the hydraulic control system adopts the hydraulic control system of the leg joint driving device of the wheel-legged robot as claimed in claim 1; one end of the thigh (36) is hinged with the vehicle body (35), and the other end of the thigh (36) is hinged with 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 size of an included angle between the vehicle body (35) and the thigh (36) and the size of an included angle between the thigh (36) and the shank (37).