Hydraulically-driven two-degree-of-freedom coupling bionic jumping robot

Abstract

The invention relates to the field of jumping robots, in particular to a hydraulically-driven two-degree-of-freedom coupling type humanoid-leg jumping robot and a control method thereof. The overall structure of the robot simulating jumping of the human legs is composed of a driving assembly, a thigh assembly and a shank assembly. The designed jumping robot is simplified into an SLIP model, a PID controller is adopted in the jumping process to achieve control over the flying phase of the jumping robot, and a PD controller is adopted in the landing phase for control. The hydraulic cylinders are far away from the legs, so that the hydraulic cylinders are driven to move to the upper body, and the whole robot has better attractiveness. And meanwhile, the lightweight design of the legs is achieved, the inertia of the legs is reduced, and the robot has more stable dynamic performance. And the vertically placed hydraulic cylinder is designed, so that the driving efficiency is further improved, and finally, more efficient bionic jumping movement is realized.

Description

Technical Field

[0001] The invention relates to a jumping robot, in particular to a hydraulically driven two-degree-of-freedom coupled bionic jumping robot. Background Art

[0002] In recent years, with the continuous improvement of motion controllers and gait planning theories, robots with high-speed running and jumping capabilities have become the focus of research, showing important application prospects in the fields of rescue, service, and military. As the core component of the robot, the design and control technology of the single leg directly affect the robot's movement ability and stability in various environments. At present, the jumping planning theory of telescopic leg single-leg robots is relatively mature, while the joint leg single-leg robots are still to be developed. The first problem to be solved for the joint single-leg robot is the drive system. The hydraulic drive system has gradually become the preferred technology for high-performance robot leg drive with its high power density and precise force control ability. However, most of the joint single-leg robot drives are generally directly installed on the legs, which will increase the weight of the legs, increase inertia, and affect the stability of the robot during high-speed jumping. Therefore, the present invention aims to design a hydraulically driven single-leg jumping bionic robot that is far away from the robot legs and vertically places the hydraulic cylinder, so that the drive can be moved to the upper body, the lightweight design of the legs can be realized, the stability and drive efficiency of the jump can be increased, and the dynamic performance and aesthetics can be better, and finally a jumping motion with bionic characteristics can be realized. Summary of the invention

[0003] The single-leg robot needs to have articulated structural characteristics, lightweight mass attributes and reliable transmission methods, and its joints should have a similar range of motion as human legs. The problem to be solved by the present invention is to design a hydraulically driven coupled single-leg jumping robot based on the problem of unstable robot jumping and poor drive utilization caused by excessive leg mass.

[0004] The technical solution adopted by the present invention to solve the technical problem is:

[0005] A hydraulically driven coupled single-leg jumping robot, characterized in that: its overall structure consists of a driving component, a thigh component and a calf component, such as Figure 1 , 2 shown.

[0006] The drive assembly is fixed on the trunk bottom plate, and the structure includes a trunk shell and a hydraulic power module fixedly connected by a bottom plate and two side plates. The structure of the hydraulic power module includes an oil tank, a motor, a hydraulic pump, a valve block, an accumulator, a thigh hydraulic cylinder, a calf hydraulic cylinder, a thigh piston rod, and a calf piston rod. The hydraulic cylinder is fixedly connected to the side plate, the piston rod is fixedly connected to the cylinder rod slider, and the cylinder rod slider is connected to the side plate through a moving pair. The motor provides the main power source for the hydraulic system, so that the hydraulic pump can extract and pressurize the hydraulic oil from the oil tank. When the demand for jumping is low, the hydraulic pump stores the excess hydraulic oil in the accumulator. When the demand is high, the accumulator will quickly release the stored hydraulic oil to supplement the flow and pressure of the system, so that the pressurized hydraulic oil is transported to the actuator hydraulic cylinder of the drive system through the valve block, thereby driving the piston rod to move, converting hydraulic energy into mechanical energy, and realizing the jumping movement of the single-legged robot.

[0007] The thigh cylinder rod slider and thigh in the thigh assembly are connected through the revolute pair and the two ends of the thigh slider connecting rod, and the thigh support is fixedly connected to the trunk bottom plate. Figure 3 As shown, the motor drives the hydraulic pump to pressurize and pump oil from the oil tank, so that the high-pressure oil flows into the thigh hydraulic cylinder, pushing the thigh piston rod to produce linear motion. The thigh lever slider connects the thigh piston rod and the thigh slider connecting rod, converting the linear motion generated by the thigh hydraulic cylinder into the rotational motion required by the thigh, driving the rotation of the thigh. The structural diagram is shown in Figure 5 .

[0008] The calf cylinder rod slider and the leg triangle connector in the calf assembly are connected through a rotating pair and the two ends of the calf slider connecting rod, and the leg triangle connector and the calf are also connected through a rotating pair and the two ends of the calf connecting rod. The foot end assembly includes two foot end supports, a foot end sensor, and the sole of the foot. Its specific structure is shown in the figure below. Figure 4 The motor drives the hydraulic pump to pump oil from the oil tank under pressure, so that the high-pressure oil flows into the calf hydraulic cylinder, pushing the calf piston rod to produce linear motion. The calf connecting rod slider connects the calf piston rod and the calf slider connecting rod, and converts the linear motion generated by the calf hydraulic cylinder into the rotational motion required by the thigh through the leg triangle connector, driving the rotation of the calf. The structural diagram is shown in Figure 6 shown.

[0009] In order to realize the jumping motion control of the jumping robot, it is necessary to perform kinematic analysis on the robot. This design uses algebraic analysis methods, such as Figure 7 Assume that the location of the hip joint is the origin, and the coordinates of the knee joint are solved by algebraic method as follows:

[0010]

[0011] The coordinates of the foot end are:

[0012]

[0013] In practical applications, we need to know the position of the foot end to calculate the required joint rotation angle, which is used to determine the rotation angle of each joint motor, that is, the inverse solution of robot kinematics. Similarly, the rotation angle of the robot's hip joint and knee joint can be obtained by algebraic analysis:

[0014]

[0015] Among them, the joint rotation angle of the jumping robot during movement has a certain geometric relationship with the extension length of the hydraulic cylinder rod, such as Figure 8 As shown, the relationship between the length of the thigh hydraulic cylinder rod movement and the hip joint rotation angle is shown in the following formula.

[0016]

[0017] After simplification, we get:

[0018]

[0019] Among them, the distance between the thigh hydraulic cylinder and the horizontal coordinate of the hip joint is x 3 ; When the thigh hydraulic cylinder rod is in the fully retracted state, the angle between the thigh slider connecting rod and the side plate is α 0 , at this time, the rotation angle of the hip joint is θ 0 ; When the thigh hydraulic cylinder rod is extended, the moving distance is Δl 1 At this time, the angle between the thigh slider link and the side plate is α, and the rotation angle of the hip joint is θ 1 ; The length of the thigh slider connecting rod is a 1 ; The distance between the connection point between the thigh slider connecting rod and the thigh and the connection point between the thigh support and the thigh is a 2 .

[0020] The calf hydraulic cylinder rod also has a corresponding relationship with the rotation angle of the hip joint and knee joint, such as Fig. 9 As shown, the mathematical expression is shown below.

[0021]

[0022] After simplification, we get:

[0023]

[0024] Among them, the distance between the calf hydraulic cylinder and the horizontal coordinate of the hip joint is x 4 , Δθ 2 is the rotation angle change of the knee joint. When the calf hydraulic cylinder rod is in the fully retracted state, the angle between the calf slider connecting rod and the side plate is β0 , at this time, the rotation angle of the knee joint is θ 0 ′; When the calf hydraulic cylinder rod is extended, the moving distance is Δl 2 At this time, the angle between the calf slider link and the side plate is β, and the rotation angle of the knee joint is θ 2 ; The length of the calf slider connecting rod is a 3 ; The distance between the thigh support and the calf slider in the leg triangle connector is a 4 ; The angle between the two sides of the triangular connector of the leg with the hip joint as the intersection is γ.

[0025] Since the robot's control system is a complex nonlinear dynamic system, the dynamic characteristics must be analyzed in the dynamic real-time control system. This design uses the Lagrangian method to calculate the dynamics of the jumping robot, such as Figure 7 shown.

[0026] The flight phase is not affected by external torque but only by gravity. Its dynamic model is shown in the following equation.

[0027]

[0028] Where M is the inertia matrix of the joint space; B is the torque term generated by the Coriolis force and centrifugal force; G is the torque term generated by gravity; τ is the joint torque matrix.

[0029] When the robot is in the ground phase, it is not only affected by gravity, but also by the support force and friction of the ground. Its dynamic equation is shown below.

[0030]

[0031] Where F is the end force, F = (F z F x ) T ; J is the Jacobian matrix, which represents the linear mapping relationship between the operation space and the joint space velocity.

[0032]

[0033] A control method for a hydraulically driven two-degree-of-freedom bionic jumping robot is characterized in that: the robot body is equivalent to a mass block, and a spring with a certain stiffness and no mass is loaded on the center of mass, which is equivalent to the joint leg of the jumping robot, and a simplified SLIP jumping robot model is established. The trajectory planning is completed and mapped to the real-time joint angle through dynamics, such as Figure 8 As shown. In the control of the flying phase of the jumping process, this design uses a PID controller to achieve tracking control of joint motion, and in the control of the landing phase, a PD controller is used, as shown in Fig. 9 shown.

[0034] In the air phase of the jumping motion, the jumping robot is only affected by gravity, which is similar to free fall motion, so the center of mass dynamic equation of the SLIP model in the air phase is:

[0035]

[0036] in, is the center of mass acceleration.

[0037] During the landing phase, the jumping robot is not only affected by gravity, but also by the support and friction of the ground. Therefore, during the landing phase, the center of mass dynamic equation of the SLIP model is:

[0038]

[0039] Where m is the mass of the center of mass; is the acceleration of the center of mass; k is the spring stiffness; z is the height of the center of mass; l 0 is the original length of the spring.

[0040] When planning the motion of the center of mass of the jumping robot to complete the jumping control, the joint angles still need to be controlled in the end. In order to make the motion trajectory of the jumping robot as consistent as possible with the planning and to minimize the influence of the ground force on the foot end during the landing process, this design adopts a PID controller in the air phase of the jumping motion, such as Fig. 9 As shown in Figure 2, PD control is used in the landing phase, as shown in Figure 2. Fig.10 shown.

[0041] The PID controller for the airborne phase is:

[0042]

[0043] Among them, k p , k i , k d are the proportional, integral, and differential gains of the PID controller; u(t) is the output of the controller; q d is the joint reference angle; q a is the joint angle; e(t) is the joint angle error.

[0044] The PD controller for the touchdown phase is:

[0045]

[0046] Among them, k sp , k sd are the proportional gain and differential gain of the PD controller respectively; u(t) is the output of the controller.

[0047] The beneficial effects of the present invention compared with the existing technology are as follows: the present invention adopts a hydraulic drive method to realize the jumping movement of the bionic robot, and its hydraulic cylinder is placed vertically and away from the robot's legs, thereby realizing a lightweight design of the legs, so that the designed humanoid leg jumping robot has a larger output torque, stronger stability, and better dynamic performance and aesthetics. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Overall schematic diagram of a hydraulically driven two-degree-of-freedom single-leg coupled jumping robot; Figure 2 Schematic diagram of the overall assembly;

[0049] Figure 3 Schematic diagram of the thigh assembly;

[0050] Figure 4 Schematic diagram of the lower leg assembly;

[0051] Figure 5 A simplified diagram of the thigh assembly structure;

[0052] Figure 6 Simplified diagram of the lower leg assembly structure;

[0053] Figure 7 Schematic diagram of kinematic and dynamic analysis;

[0054] Figure 8 Schematic diagram of the relationship between the extension length of the thigh hydraulic cylinder rod and the rotation angle of the joint; Fig. 9 Schematic diagram of the relationship between the extension length of the calf hydraulic cylinder rod and the rotation angle of the joint; Fig.10 Schematic diagram of the robot control architecture;

[0055] Fig.11 Schematic diagram of PID motion control in the air phase;

[0056] Fig.12 Schematic diagram of PD motion control during the landing phase.

[0057] In the figure: drive module (1), thigh assembly (2), calf assembly (3), side plate (4), calf hydraulic cylinder (5), calf piston rod (6), hydraulic cylinder (7), calf connecting rod slider (8), calf slider connecting rod (9), trunk base plate (10), leg triangle connecting member (11), calf connecting rod (12), calf (13), foot end support (14), foot end sensor (15), foot end (16), thigh (17), thigh support member (18), thigh slider connecting rod (19), thigh connecting rod slider (20), side plate (21), thigh piston rod (22), thigh hydraulic cylinder (23), motor (24), hydraulic pump (25), oil tank (26), valve block (27), sleeve (28), flange bearing (29), sleeve (30).

[0058] The beneficial effects of the present invention compared with the existing technology are as follows: the present invention adopts a hydraulic drive method to realize the jumping movement of the bionic robot, and its hydraulic cylinder is placed vertically and away from the robot's legs, thereby realizing a lightweight design of the legs, so that the designed humanoid leg jumping robot has a larger output torque, stronger stability, and better dynamic performance and aesthetics. DETAILED DESCRIPTION

[0059] The present invention will be further described in conjunction with the accompanying drawings.

[0060] A hydraulically driven articulated single-leg jumping robot, the overall structure of which is composed of a driving component (1), a thigh component (2) and a shank component (3), such as Figure 1 , 2 shown.

[0061] The drive assembly (1) is fixed on the trunk base plate (10), and the structure includes a trunk shell and a hydraulic power module fixedly connected by the base plate (10) and two side plates (4, 21). The structure of the hydraulic power module includes an oil tank (26), a motor (24), a hydraulic pump (25), a valve block (27), an accumulator (7), a thigh hydraulic cylinder (23), a calf hydraulic cylinder (5), a thigh piston rod (22), and a calf piston rod (6). The hydraulic cylinder (23, 5) and the side plates (21, 4) are fixedly connected, the piston rod (22, 6) and the cylinder rod slider (20, 8) are fixedly connected, and the cylinder rod slider (20, 8) is connected to the side plates (21, 4) through a moving pair. The motor (24) provides the main power source for the hydraulic system, so that the hydraulic pump (25) can extract and pressurize the hydraulic oil from the oil tank (26). When the demand for jumping is low, the hydraulic pump (25) stores the excess hydraulic oil in the accumulator (7). When the demand is high, the accumulator (7) will quickly release the stored hydraulic oil to supplement the flow and pressure of the system, so that the pressurized hydraulic oil is transported to the actuator hydraulic cylinder (23, 5) of the drive system through the valve block (27), thereby pushing the piston rod (22, 6) to move, converting hydraulic energy into mechanical energy, and realizing the jumping movement of the single-legged robot.

[0062] The thigh cylinder rod slider (20) and the thigh (17) in the thigh assembly are connected through the revolving pair and the two ends of the thigh slider connecting rod (19), and the thigh support member (18) is fixedly connected to the trunk bottom plate. Figure 3 As shown, the motor (24) drives the hydraulic pump (25) to pressurize and pump oil from the oil tank (26), so that the high-pressure oil flows into the thigh hydraulic cylinder (23), pushing the thigh piston rod (22) to produce linear motion. The thigh cylinder rod slider (20) connects the thigh piston rod (22) and the thigh slider connecting rod (19), converting the linear motion generated by the thigh hydraulic cylinder (23) into the rotational motion required by the thigh, thereby driving the thigh (17) to rotate. The structural schematic diagram is shown in FIG. Figure 5 shown.

[0063] The calf cylinder rod slider (8) and the leg triangle connector (11) in the calf assembly are connected through a revolving pair and the two ends of the calf slider connecting rod (8), and the leg triangle connector (11) and the calf (13) are also connected through a revolving pair and the two ends of the calf connecting rod (12). Figure 4 The motor (24) drives the hydraulic pump (25) to pump oil from the oil tank (26) under pressure, so that the high-pressure oil flows into the calf hydraulic cylinder (5), pushing the calf piston rod (6) to produce linear motion. The calf connecting rod slider (8) connects the calf piston rod (6) and the calf slider connecting rod (9), and converts the linear motion generated by the calf hydraulic cylinder (5) into the rotational motion required by the thigh through the leg triangle connecting member (11), thereby driving the rotation of the calf (13). The structural diagram is shown in FIG. Figure 6 shown.

[0064] In order to realize the jumping motion control of the jumping robot, it is necessary to conduct kinematic analysis of the robot. This design uses algebraic analysis methods, such as Figure 7 Assume that the location of the hip joint is the origin, and the coordinates of the knee joint are solved by algebraic method as follows:

[0065]

[0066] The coordinates of the foot end are:

[0067]

[0068] In practical applications, we need to know the position of the foot end to calculate the required joint rotation angle, which is used to determine the rotation angle of each joint motor, that is, the inverse solution of robot kinematics. Similarly, the rotation angle of the robot's hip joint and knee joint can be obtained by algebraic analysis:

[0069]

[0070] The rotation angle of the joints of the jumping robot during movement has a certain geometric relationship with the extension length of the hydraulic cylinder rod (22, 6), and the relationship between the moving length of the thigh hydraulic cylinder rod (22) and the rotation angle of the hip joint is as shown in the following formula.

[0071]

[0072] After simplification, we get:

[0073]

[0074] The distance between the thigh hydraulic cylinder (23) and the horizontal coordinate of the hip joint is x 3 When the thigh hydraulic cylinder rod (22) is in a fully retracted state, the angle between the thigh slider connecting rod (19) and the side plate (21) is α 0 , at this time, the rotation angle of the hip joint is θ 0 When the thigh hydraulic cylinder rod (22) is extended, the moving distance is Δl 1 At this time, the angle between the thigh slider connecting rod (19) and the side plate (21) is α, and the rotation angle of the hip joint is θ 1 ; The length of the thigh slider connecting rod (19) is a 1 The distance between the connection point between the thigh slider connecting rod (19) and the thigh (17) and the connection point between the thigh support member (18) and the thigh (17) is a 2 .

[0075] The relationship between the calf hydraulic cylinder rod (6) and the knee joint rotation angle is shown in the following equation.

[0076]

[0077] After simplification, we get:

[0078]

[0079] The distance between the calf hydraulic cylinder (5) and the horizontal coordinate of the hip joint is x 4 , Δθ 2 is the rotation angle variation of the knee joint, and when the calf hydraulic cylinder rod (6) is in a fully retracted state, the angle between the calf slider connecting rod (8) and the side plate (4) is β 0 , at this time, the rotation angle of the knee joint is θ 0 '; When the calf hydraulic cylinder rod (6) is extended, the moving distance is Δl 2 At this time, the angle between the calf slider connecting rod (9) and the side plate (4) is β, and the rotation angle of the knee joint is θ 2 ; The length of the calf slider connecting rod (9) is a 3 The distance between the thigh support member (18) and the calf slider connecting rod (9) in the leg triangle connecting member (11) is a 4 The angle between the two sides of the triangular leg connector (11) with the hip joint as the intersection is γ.

[0080] Since the robot's control system is a complex nonlinear dynamic system, the dynamic characteristics must be analyzed in the dynamic real-time control system. This design uses the Lagrangian method to calculate the dynamics of the jumping robot, such as Figure 7 shown.

[0081] The robot's jumping process can be divided into the flight phase and the landing phase. The flight phase refers to the stage when the robot's feet leave the ground, including the moment of leaving the ground and moving in the air. The flight phase is not affected by external torque, but only by gravity. Its dynamic model is shown as follows

[0082]

[0083] Where M is the inertia matrix of the joint space; B is the torque term generated by the Coriolis force and centrifugal force; G is the torque term generated by gravity; τ is the joint torque matrix.

[0084] The landing phase refers to the stage when the robot's feet touch the ground, including the moment of contact, and the jump is generated by the reaction force of the ground. When the robot is in the landing phase, it is not only affected by gravity, but also by the support force and friction of the ground. Its dynamic equation is shown in the following formula.

[0085]

[0086] Where F is the end force, F = (F z F x ) T ; J is the Jacobian matrix, which represents the linear mapping relationship between the operation space and the joint space velocity.

[0087]

[0088] A control method for a hydraulically driven two-degree-of-freedom bionic jumping robot is characterized in that: the robot body is equivalent to a mass block, and a spring with a certain stiffness and no mass is loaded on the center of mass, which is equivalent to the joint leg of the jumping robot, and a simplified SLIP jumping robot model is established. The trajectory planning is completed and mapped to the real-time joint angle through dynamics, such as Figure 8 As shown. In the control of the flying phase of the jumping process, this design uses a PID controller to achieve tracking control of joint motion, such as Fig. 9 As shown, in the control of the landing phase, a PD controller is used, such as Fig.10 shown.

[0089] In the air phase of the jumping motion, the jumping robot is only affected by gravity, which is similar to free fall motion, so the center of mass dynamic equation of the SLIP model in the air phase is:

[0090]

[0091] in, is the center of mass acceleration.

[0092] During the landing phase, the jumping robot is not only affected by gravity, but also by the support and friction of the ground. Therefore, during the landing phase, the center of mass dynamic equation of the SLIP model is:

[0093]

[0094] Where m is the mass of the center of mass; is the acceleration of the center of mass; k is the spring stiffness; z is the height of the center of mass; l 0 is the original length of the spring.

[0095] When the center of mass of the jumping robot is motion-planned to complete the jumping control, the joint angles still need to be controlled in the end. In order to make the motion trajectory of the jumping robot as consistent as possible with the plan and to minimize the influence of the ground force on the foot end during the landing process, this design uses a PID controller in the flight phase of the jumping motion and a PD control in the landing phase.

[0096] The PID controller for the airborne phase is:

[0097]

[0098] Among them, k p , k i , k d are the proportional, integral, and differential gains of the PID controller; u(t) is the output of the controller; q d is the joint reference angle; q a is the joint angle; e(t) is the joint angle error.

[0099] The PD controller for the touchdown phase is:

[0100]

[0101] Among them, k sp , k sd are the proportional gain and differential gain of the PD controller respectively; u(t) is the output of the controller.

Claims

1. A hydraulically driven two-degree-of-freedom coupled humanoid leg jumping robot, characterized in that: Its overall structure consists of a driving component (1), a thigh component (2) and a calf component (3); The structure of the driving assembly (1) includes a trunk shell composed of a bottom plate (10), two side plates (4, 21), and an oil tank (26), a motor (24), a hydraulic pump (25), a valve block (27), an accumulator (7), a thigh hydraulic cylinder (23), a calf hydraulic cylinder (5), a thigh piston rod (22), and a calf piston rod (6); wherein the motor (24) provides a main power source for the hydraulic system, so that the hydraulic pump (25) can extract and pressurize the hydraulic oil from the oil tank (26); when the demand for jumping is low, the hydraulic pump (25) stores the excess hydraulic oil in the accumulator (7); when the demand is high, the accumulator (7) will quickly release the stored hydraulic oil to supplement the flow and pressure of the system, so that the pressurized hydraulic oil is transported to the actuator hydraulic cylinder (23, 5) of the driving system through the valve block (27), thereby pushing the piston rod (22, 6) to move, converting the hydraulic energy into mechanical energy, and realizing the jumping movement of the single-legged robot; The thigh component mainly comprises a thigh piston rod (22), a thigh cylinder rod slider (20), a thigh slider connecting rod (19), a thigh support member (18), and a thigh (17); wherein the motor (24) drives the hydraulic pump (25) to pressurize and extract oil from the oil tank (26), so that the high-pressure oil flows into the thigh hydraulic cylinder (23), pushing the thigh piston rod (22) to generate linear motion; the thigh cylinder rod slider (20) connects the thigh piston rod (22) and the thigh slider connecting rod (19), converting the linear motion generated by the thigh hydraulic cylinder (23) into the rotational motion required by the thigh, thereby driving the thigh (17) to rotate; The calf assembly mainly comprises a calf piston rod (6), a calf cylinder rod slider (8), a calf slider connecting rod (8), a leg triangular connecting piece (11), a calf connecting rod (12), and a calf (13); wherein the motor (24) drives the hydraulic pump (25) to pressurize and extract oil from the oil tank (26), so that the high-pressure oil flows into the calf hydraulic cylinder (5), pushing the calf piston rod (6) to generate linear motion; the calf connecting rod slider (8) connects the calf piston rod (6) and the calf slider connecting rod (9), and converts the linear motion generated by the calf hydraulic cylinder (5) into the rotational motion required by the thigh through the leg triangular connecting piece (11), thereby driving the rotation of the calf (13).

2. A hydraulically driven two-degree-of-freedom coupled humanoid leg jumping robot as claimed in claim 1, characterized in that: The motor (24) drives the hydraulic pump (25) to pressurize and pump oil from the oil tank (26), so that the hydraulic oil flows into the thigh hydraulic cylinder (23) and the calf hydraulic cylinder (5), thereby pushing the thigh piston rod (22) and the calf piston rod (6) to produce linear motion, thereby pushing the thigh connecting rod slider (20) and the calf connecting rod slider (8) to move, driving the thigh slider connecting rod (19) and the calf slider connecting rod (9) to produce rotational motion, and finally pushing the thigh (17) to produce rotational motion around the hip joint, and the calf slider connecting rod (9) pushes the leg triangle (11) to rotate, driving the calf connecting rod (12) to move, thereby pushing the calf (13) to produce rotational motion.

3. A control method for a hydraulically driven two-degree-of-freedom coupled humanoid leg jumping robot, characterized in that: The robot body is equivalent to a mass block, and a spring with a certain stiffness and no mass is loaded on the center of mass, which is equivalent to the joint leg of the jumping robot. A simplified SLIP jumping robot model is established; and the trajectory planning is completed, and the real-time joint angle is mapped through dynamics, as shown in Figure 8; Among them, in the control of the flying phase of the jumping process, this design uses a PID controller to achieve tracking control of the joint movement, as shown in Figure 9, and in the control of the landing phase, a PD controller is used, as shown in Figure 10; In the air phase of the jumping motion, the jumping robot is only affected by gravity, which is similar to free fall motion, so the center of mass dynamic equation of the SLIP model in the air phase is: in, is the center of mass acceleration; During the landing phase, the jumping robot is not only affected by gravity, but also by the support and friction of the ground. Therefore, during the landing phase, the center of mass dynamic equation of the SLIP model is: Where m is the mass of the center of mass; is the acceleration of the center of mass; k is the spring stiffness; z is the height of the center of mass; l0 is the original length of the spring; When the center of mass of the jumping robot is motion-planned to complete the jumping control, the joint angle still needs to be controlled in the end; in order to make the motion trajectory of the jumping robot as consistent as possible with the plan and to minimize the influence of the ground force on the foot end during the landing process, this design adopts PID controller in the flying phase of the jumping motion and PD control in the landing phase; The PID controller for the empty phase is: Among them, k p , k i , k d are the proportional, integral, and differential gains of the PID controller; u(t) is the output of the controller; q d is the joint reference angle; q a is the joint angle; e(t) is the joint angle error; The PD controller for the touchdown phase is: Among them, k sp , k sd are the proportional gain and differential gain of the PD controller respectively; u(t) is the output of the controller.

4. The hydraulically driven two-degree-of-freedom coupled humanoid leg jumping robot according to claim 1, characterized in that: The hydraulic cylinder is placed on the torso, moving the drive to the upper body, which has better aesthetics; at the same time, it realizes a lightweight design of the legs, reduces leg inertia, and thus has better dynamic performance.

5. The hydraulically driven two-degree-of-freedom coupled humanoid leg jumping robot according to claim 2, characterized in that: Placing the hydraulic cylinder vertically reduces the loss during energy transfer, increases the utilization rate of the drive, and increases the endurance of the jumping robot.

6. The control method of the hydraulically driven two-degree-of-freedom coupled humanoid leg jumping robot according to claim 3, characterized in that: The designed jumping robot is simplified into a SLIP jumping model. During the jumping process, a PID controller is used to control the jumping robot in the air phase, and a PD controller is used to control the jumping robot in the landing phase, thereby completing the jumping motion with bionic characteristics.

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