A closed-chain leg mechanism of a walking robot and a foot-end trajectory control method thereof

Abstract

The present invention discloses a closed-chain leg mechanism of a walking robot and a foot-end trajectory control method thereof, which relates to the field of robot technology. The leg mechanism includes a first third sub-component, a second third sub-component and a third third sub-component, as well as a first second sub-component, a second second sub-component, a third second sub-component, a fourth second sub-component and a fifth second sub-component. The first third sub-component is used as the body of the robot, and the fifth second sub-component is used as the foot of the robot; the foot end p of the fifth second sub-component is a free end and contacts the ground. The present invention also provides a foot-end trajectory control method for a walking robot, which only requires a prime mover to rotate 360° in a full circle to achieve a predetermined walking motion, and is easy to control; it includes a composite hinge, which is convenient for kinematic analysis of the mechanism, reduces the space occupied by the leg structure, has a compact structure, and is conducive to reducing the size, weight and manufacturing cost of the robot leg mechanism; it meets the walking motion requirements of the robot leg and has excellent comprehensive performance.

Description

Technical Field

[0001] The present invention relates to the technical field of walking robots, and more specifically to a closed-chain leg mechanism of a walking robot and a foot end trajectory control method thereof. Background Art

[0002] Legged robots have better adaptability and flexibility in complex environments. The closed-chain legged structure is generally characterized by a single degree of freedom and a crank full-circle rotation drive. This structural design can make the gait trajectory continuous. When repeated commutation drive is used, the frequent forward and reverse switching of the drive will bring impact and increase energy loss, which has a certain impact on the movement speed, movement efficiency and carrying capacity of the legged robot. Compared with repeated commutation drive, crank full-circle rotation can improve the robot's movement efficiency, reduce energy loss, and reduce the difficulty of the control algorithm.

[0003] The Chinese utility model patent with publication number CN203528632U discloses an eight-legged walking robot, which is connected to a base frame by a shock-absorbing spring to achieve a shock-absorbing function, thereby improving the obstacle-crossing ability; the walking trajectory curve is amplified by a scaling mechanism to increase the stride distance and the leg-lifting height; the synchronous movement of the unilateral pairs of feet is achieved by using a crankshaft, and the four legs of the robot touch the ground at the same time, and the pairs of feet touch the ground alternately to achieve walking movements, making the eight-legged walking robot more stable during walking.

[0004] However, the above-mentioned walking robot is not only complex in structure, but also difficult to achieve a predetermined walking trajectory; in addition, the kinematic analysis is complicated and the space occupied by the leg structure is increased. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a walking robot to solve the technical problems of existing walking robots that are complex in structure, occupy a large space and are difficult to achieve a predetermined trajectory.

[0006] To achieve the above objectives, the first objective of the present invention is to provide a closed-chain leg mechanism of a walking robot, comprising a first three-part sub-component, a second three-part sub-component, a third three-part sub-component, and a first second part sub-component, a second second part sub-component, a third second part sub-component, a fourth second part sub-component, and a fifth second part sub-component, wherein:

[0007] The first three components are used as the body of the robot, and the fifth two components are used as the feet of the robot;

[0008] One end of the first two sub-components is hinged to the first three sub-components through hinge c, and the other end is hinged to the second three sub-components and the third three sub-components through hinge f; one end of the second two sub-components is hinged to the first three sub-components through hinge a, and the other end is hinged to the third three sub-components through hinge d; one end of the third two sub-components is hinged to the first three sub-components through hinge b, and the other end is hinged to the second three sub-components through hinge g;

[0009] One end of the fourth second auxiliary component is hinged to the third third auxiliary component through a hinge e, and the other end is hinged to one end of the fifth second auxiliary component through a hinge q; the other end of the fifth second auxiliary component is hinged to the second third auxiliary component through a hinge h, and the foot end p of the fifth second auxiliary component is a free end and contacts the ground.

[0010] Preferably, it also includes:

[0011] A power system, used for driving the first two auxiliary components to rotate 360° around the first three auxiliary components through the hinge c;

[0012] A sensor system, arranged on the first three components, for collecting data of the external terrain environment;

[0013] A control system is arranged on the first three components, and the control system is electrically connected to the power system and the sensor system respectively.

[0014] Preferably, the power system is any one of an internal combustion engine, an electric motor, a steam turbine and a hydraulic system.

[0015] Preferably, the first three sub-components, the second three sub-components and the third three sub-components are all triangular plate structures, and hinges are respectively installed at the three vertices of the triangular plate structure.

[0016] Preferably, the first two auxiliary components, the second two auxiliary components, the third two auxiliary components and the fourth two auxiliary components are all connecting rod structures.

[0017] Preferably, the first three sub-components are fixedly arranged at one side between hinge a and hinge b, and the fifth second sub-component is a triangular plate structure.

[0018] Preferably, the degrees of freedom of the closed-chain leg mechanism F The calculation expression is:

[0019] F = 3 n - 2 P L - P H

[0020] in: n is the number of active components, P L is the number of low pairs, P H is the number of high pairs.

[0021] Preferably, the movement trajectory of the foot end p of the fifth second auxiliary component is a smooth arc that first rises and then falls, with the bottom approaching a straight line and the top forming a smooth arc.

[0022] The second object of the present invention is to provide a foot-end trajectory control method using the closed-chain leg mechanism of the walking robot described above, the foot-end trajectory control method comprising the steps of:

[0023] Step S 100 :The control system collects the spatial state data of the walking robot during movement and the environmental sensing data of the external terrain through the sensor system;

[0024] Step S 200 : The control system plans the foot trajectory for different road conditions according to the environmental sensor data and leg mechanism parameters;

[0025] Step S 300 : The control system performs kinematic calculations according to the foot end trajectory planning, obtains the calculated expected value of the foot end p of the fifth second auxiliary component, and converts it into a control signal of the power system to control the output power of the power system;

[0026] Step S 400 :The control system receives the feedback value signal of the sensor system, calculates the error according to the expected value and feedback value of the power system, performs fuzzy PID processing on the error value, and outputs the control amount to realize the precise control of the rotation speed of the first and second auxiliary components;

[0027] Step S 500 : Through the precise control of the power system, the movement of the leg mechanism is executed, thereby achieving precise control of the foot end p of the fifth second auxiliary component.

[0028] Compared with the prior art, the present invention has the following advantages and effects:

[0029] 1. The closed-chain leg mechanism of the walking robot in the present invention is composed of 8 components and 9 hinges, wherein the first second component, the second second component, the third second component, the fourth second component and the fifth second component are two-component components, i.e., they are hinged to other components through two hinges; the first third component, the second third component and the third third component are three-component components, i.e., they are hinged to other components through three hinges, so that the closed-chain leg mechanism is a planar mechanism with 1 degree of freedom, which only includes one type of kinematic pair, i.e., a revolute pair, and has a simple structure and a reasonable size ratio of each component; only one prime mover (i.e., the first second component) is required to make a 360° rotation. The predetermined walking motion can be achieved by rotating a full circle, and the control is simple; the mechanism includes a composite hinge, which is convenient for the kinematic analysis of the mechanism, can reduce the space occupied by the leg structure, and has a compact structure, which is beneficial to reducing the size, weight and manufacturing cost of the robot leg mechanism; the foot end p of the fifth second auxiliary component serves as the output point of the entire mechanism, and can output a predetermined motion trajectory, the bottom of which approaches a straight line, and the top forms a smooth arc that first rises and then falls, which meets the walking motion requirements of the robot leg; the mechanism has a reasonable and uniquely determined motion trajectory during the motion process, the components do not interfere with each other during the motion process, and has excellent comprehensive performance.

[0030] 2. The above-mentioned closed-chain leg mechanism not only has a simple structure, can realize the predetermined walking trajectory, reduce the complexity of kinematic analysis, but also further reduce the space occupied by the leg structure; the walking robot can adapt to complex terrain, improve load off-road capability, and improve the control accuracy and real-time performance of the leg mechanism movement, maintain the smoothness and control stability of the leg mechanism, and has high foot-end trajectory control accuracy, which has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the planar structure of the closed-chain leg mechanism of the walking robot in an embodiment of the present invention;

[0032] Figure 2 Schematic diagram of the walking trajectory curve of the closed-chain leg mechanism in an embodiment of the present invention;

[0033] Figure 3 Schematic diagram of the three-dimensional structure of the closed-chain leg mechanism of the walking robot in an embodiment of the present invention;

[0034] Figure 4 Schematic diagram of the foot trajectory control method of a walking robot in an embodiment of the present invention.

[0035] Description of reference numerals:

[0036] 1- first third sub-component; 2- first second sub-component; 3- second second sub-component; 4- third second sub-component; 5- second third sub-component; 6- third third sub-component; 7- fourth second sub-component; 8- fifth second sub-component. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] See also Figure 1-3 As shown, an embodiment of the present invention provides a closed-chain leg mechanism of a walking robot, wherein the closed-chain leg mechanism includes a first three-part sub-component 1, a second three-part sub-component 5, a third three-part sub-component 6, a first second second-part sub-component 2, a second second second-part sub-component 3, a third second second-part sub-component 4, a fourth second second-part sub-component 7, and a fifth second second-part sub-component 8, wherein:

[0043] The first third sub-component 1 is used as the body of the robot, and the fifth second sub-component 8 is used as the foot of the robot; one end of the first second sub-component 2 is hinged to the first third sub-component 1 through a hinge c, and the other end is hinged to the second third sub-component 5 and the third third sub-component 6 through a hinge f; one end of the second second sub-component 3 is hinged to the first third sub-component 1 through a hinge a, and the other end is hinged to the third third sub-component 6 through a hinge d; one end of the third second sub-component 4 is hinged to the first third sub-component 1 through a hinge b, and the other end is hinged to the second third sub-component 5 through a hinge g; one end of the fourth second sub-component 7 is hinged to the third third sub-component 6 through a hinge e, and the other end is hinged to one end of the fifth second sub-component 8 through a hinge q; the other end of the fifth second sub-component 8 is hinged to the second third sub-component 5 through a hinge h, and the foot end p of the fifth second sub-component 8 is a free end and in contact with the ground.

[0044] Specifically in this embodiment, the closed-chain leg mechanism is a 1-degree-of-freedom planar mechanism, which only includes one type of kinematic pair, a revolute pair, with a simple structure and reasonable size ratios of each component; only one prime mover (i.e., the first second component 2) is required to rotate 360° to achieve the predetermined walking motion, and the control is simple; the mechanism includes a composite hinge, which is convenient for kinematic analysis of the mechanism, can reduce the space occupied by the leg structure, has a compact structure, and is conducive to reducing the size, weight and manufacturing cost of the robot leg mechanism; the foot end p of the fifth second component 8 is the output point of the entire mechanism, and can output a predetermined motion trajectory such as Figure 2 As shown, the bottom of the trajectory approaches a straight line, and the top forms a smooth arc that first rises and then falls, which meets the walking movement requirements of the robot's legs; the mechanism has a reasonable and uniquely determined motion trajectory during the movement, and the components do not interfere with each other during the movement, with excellent comprehensive performance.

[0045] For further information, see Figure 1 As shown, the closed-chain leg mechanism of the walking robot also includes a power system, a sensor system and a control system, wherein:

[0046] The power system is used to drive the first and second auxiliary components 2 to rotate 360° around the first and third auxiliary components 1 through the hinge c; the sensor system is arranged on the first and third auxiliary components 1 to collect data on the external terrain environment; the control system is arranged on the first and third auxiliary components 1, and the control system is electrically connected to the power system and the sensor system respectively.

[0047] Specifically in this embodiment, the power system is responsible for driving the leg components of the walking robot to move. Generally speaking, the power system usually involves the control of the motor, for example, the control system issues a speed command to control the movement of the robot. In this embodiment, the power system is used to drive the first and second auxiliary components 2 to rotate 360 ​​degrees around the first and third auxiliary components 1 through the hinge c. At this time, the power system needs to provide sufficient torque and precise speed control to achieve continuous movement of the legs.

[0048] The sensor system is responsible for collecting data about the external environment. Generally speaking, the sensor system includes visual sensors, sound sensors, and tactile sensors, etc. These sensors can help the robot detect and collect environmental data. In this embodiment, the sensor system is arranged on the first three components 1, and is used to collect data about the external terrain environment. The external terrain environment data includes information such as ground hardness, slope, obstacles, etc., so that the robot can adapt to different terrains.

[0049] The control system is responsible for processing the data input by the sensor system and generating control signals to drive the actuators. In this embodiment, the control system is arranged on the first three sub-components 1 and is electrically connected to the power system and the sensor system, so that the control system can quickly respond to the data of the sensors and adjust the output of the power system in real time to ensure that the robot can walk stably and adapt to changes in terrain.

[0050] Furthermore, the power system is any one of an internal combustion engine, an electric motor, a steam turbine and a hydraulic system.

[0051] For example, when the power system is an internal combustion engine, the internal combustion engine is a device that directly converts the heat energy generated by the combustion of fuel in the cylinder into mechanical energy. It is mainly composed of a cylinder, a piston, a connecting rod mechanism, and a valve mechanism. The fuel burns in the cylinder, expands in volume, and pushes the piston to reciprocate. The piston then converts the reciprocating motion into circular motion through the connecting rod mechanism to output work. The internal combustion engine has a high power-to-weight ratio and is suitable for application scenarios that require high power density, such as mobile robots.

[0052] When the power system is an electric motor, the electric motor converts electrical energy into mechanical energy through electromagnetic action. It can directly convert electrical energy into rotational motion without the need for a complex mechanical conversion process. The electric motor has the advantages of high efficiency, low noise, easy control and simple maintenance, and is suitable for application scenarios that require precise control and frequent start and stop.

[0053] When the power system is a steam turbine, since the steam turbine is an external combustion engine, the high-temperature and high-pressure steam expands between the rotor blades in the cylinder to do work, driving the rotor to rotate at high speed, and the rotor then drives other equipment to work, such as generators. Steam turbines can easily achieve a relatively large single-machine power and are not picky about fuel. They can use cheap fuels such as heavy oil and residual oil.

[0054] When the power system is a hydraulic system, the hydraulic system uses the pressure energy of the liquid to transmit power and motion. It converts the pressure energy of the liquid into mechanical energy through components such as hydraulic pumps, hydraulic cylinders, and hydraulic motors. The hydraulic system can provide greater force and torque, and is suitable for application scenarios that require high force output, with fast response speed and high control accuracy.

[0055] Specifically, the choice of power system depends on the specific application scenario and requirements of the walking robot. For example, if high power output and infrequent starting and stopping are required, an internal combustion engine may be a better choice; if precise control and fast response are required, an electric motor may be more suitable; if continuous and stable power output is required and fuel costs are sensitive, steam turbines and hydraulic systems may be an option to consider. Each power system has its own unique advantages and limitations, and needs to be selected based on the actual application.

[0056] For further information, see Figure 1 As shown, the first triple sub-component 1, the second triple sub-component 5 and the third triple sub-component 6 are all triangular plate structures, and hinges are respectively installed at the three vertices of the triangular plate structure.

[0057] Specifically in this embodiment, the first three-component 1, the second three-component 5, and the third three-component 6 are all hinged to other components through three hinges. The triangular plate structure has high mechanical stability due to its geometric characteristics. In a walking robot, this structure can provide a stable support platform so that the robot can maintain balance on different terrains. Therefore, applying the triangular plate structure to the legs of the robot can simulate the stable walking method of insects in nature.

[0058] Secondly, the space occupied by the triangular plate structure is relatively small, which makes the design of the robot more compact. In a limited space, the triangular plate structure can provide sufficient strength and rigidity while reducing the use of materials.

[0059] Furthermore, the triangular plate structure of the robot's legs can be designed to be variable to adapt to different terrains and movement requirements, improving the adaptability of the walking robot to complex environments; the triangular plate structure can also be combined with other mechanical structures, such as a four-bar linkage, to achieve more complex movement patterns. This structure can make the robot more flexible when walking and can simulate the gait of organisms in nature.

[0060] Finally, the triangular plate structure can carry heavier loads due to its stability and strength; the triangular plate structure can be combined with a linear drive mechanism to offset the movement of the leg mechanism through the up and down movement of the cosine function, thereby improving energy efficiency.

[0061] For further information, see Figure 1As shown, the first second auxiliary component 2, the second second auxiliary component 3, the third second auxiliary component 4 and the fourth second auxiliary component 7 are all connecting rod structures.

[0062] Specifically, the first second auxiliary component 2, the second second auxiliary component 3, the third second auxiliary component 4 and the fourth second auxiliary component 7 in this embodiment are all hinged to other components through two hinges. Figure 1 The leg mechanism of the walking robot shown is a linkage mechanism consisting of 8 components and 9 hinges, and its core function is to convert the rotational motion into the predetermined trajectory motion of the linkage.

[0063] Therefore, during the walking process of the walking robot, the connecting rod mechanism can convert the extension and contraction movement of the legs into the rotation of the joints (that is, the connecting rod structure and the triangular plate structure), thereby realizing the flexible movement of the legs; the connecting rod mechanism can convert the source power into the torque of the components, output mechanical energy to the outside, and can effectively transmit the force generated by the power system to each joint of the leg (connecting rod structure and triangular plate structure), realizing the transmission and effective utilization of force. In addition, the movement characteristics of the connecting rod mechanism include no dead point position, which makes the movement of the robot legs smoother and more controllable.

[0064] Therefore, the application of the linkage mechanism in the legs of walking robots can provide efficient force transmission, precise motion control, compact structural design, and good adaptability and evolutionary capabilities, thereby achieving efficient and stable walking.

[0065] It should be particularly noted that the structures of the first third sub-component 1, the second third sub-component 5 and the third third sub-component 6 as well as the first second sub-component 2, the second second sub-component 3, the third second sub-component 4, the fourth second sub-component 7 and the fifth second sub-component 8 can be designed and processed into any shape according to actual application scenarios to meet different application requirements.

[0066] For further information, see Figure 1 As shown, the first three sub-components 1 are fixedly arranged on one side between hinges a and hinges b, and the fifth two sub-components 8 are triangular plate structures. Specifically, the fixedly arranged components provide a stable support point for the robot leg, improving the stiffness and stability of the entire leg mechanism; the fixed arrangement of the first three sub-components 1 allows for accurate analysis of the kinematics of the leg mechanism, and by establishing a fixed coordinate system for the leg, the movement of the leg mechanism can be described and predicted in detail, which is essential for understanding and optimizing the movement trajectory of the robot leg.

[0067] In addition, the fifth secondary component 8 in the walking robot is a triangular plate structure, which mainly provides stability, support and force transmission while maintaining the adaptability and flexibility of the structure. This structural design helps the robot maintain balance and efficiency in various environments.

[0068] For further information, see Figure 1 , 3 As shown, the degrees of freedom of the closed-chain leg mechanism F The calculation expression is:

[0069] F = 3 n - 2 P L - P H

[0070] in: n is the number of active components, P L is the number of low pairs, P H is the number of high pairs.

[0071] Specifically in the embodiment of the present invention, except for the first third sub-component 1 as the frame, the other seven components, namely the first second sub-component 2, the second second sub-component 3, the third second sub-component 4, the second third sub-component 5, the third third sub-component 6, the fourth second sub-component 7, and the fifth second sub-component 8 are all movable components. n = 7.

[0072] Hinge ae, hinge g, hinge h and hinge q are 8 revolute pairs; hinge f is a compound hinge, which is equivalent to 2 revolute pairs. Therefore, the total number of revolute pairs in the closed-chain leg mechanism is 10. The mechanism does not contain kinematic pairs other than revolute pairs. Therefore P L =10.

[0073] The closed-chain leg mechanism does not contain a high pair, so P H = 0.

[0074] Based on the above analysis, the degrees of freedom of the closed-chain leg mechanism are F =3 n - 2 P L - P H = 3×7 - 2×10 - 0 = 1, which means that the mechanism is a planar mechanism with 1 degree of freedom and only needs 1 prime mover to achieve the predetermined walking motion.

[0075] The first and second auxiliary components 2 are the prime movers of the mechanism, i.e., the power input components. When the first and second auxiliary components 2 rotate 360° relative to the first and third auxiliary components 1 (frame), other movable components will move accordingly. The fifth and second auxiliary components 8 are the actuator components, and the motion trajectory at the end point p is as follows: Figure 2 As shown, this is the walking trajectory of the robot.

[0076] It needs further explanation that the low pair specifically refers to a kinematic pair with surface contact such as a rotating pair or a translating pair, and the high pair specifically refers to a kinematic pair with point-line contact such as a gear pair or a cam pair.

[0077] For further information, see Figure 1 , 2 As shown, the movement trajectory of the foot end p of the fifth second auxiliary component 8 is a smooth arc that first rises and then falls, with the bottom approaching a straight line and the top forming a smooth arc.

[0078] During the robot's movement, the legs need to move forward smoothly to maintain the overall stability of the robot. Figure 2 The bottom of the walking trajectory shown is close to a straight line, and the top forms a smooth arc that first rises and then falls, which meets the walking movement requirements of the robot's legs.

[0079] See also Figure 4 As shown, an embodiment of the present invention further provides a foot end trajectory control method of a walking robot, the foot end trajectory control method comprising the steps of:

[0080] Step S 100 :The control system collects the spatial state data of the walking robot during movement and the environmental sensing data of the external terrain through the sensor system;

[0081] Step S 200 : The control system plans the foot trajectory for different road conditions according to the environmental sensor data and leg mechanism parameters;

[0082] Step S 300 : The control system performs kinematic calculations according to the foot end trajectory planning, obtains the calculated expected value of the foot end p of the fifth second auxiliary component 8, and converts it into a control signal of the power system to control the output power of the power system;

[0083] Step S 400 : The control system receives the feedback value signal of the sensor system, calculates the error according to the expected value and feedback value of the power system, performs fuzzy PID processing on the error value, and outputs the control amount to realize the precise control of the rotation speed of the first and second auxiliary components 2;

[0084] Step S 500 : Through the precise control of the power system, the movement of the leg mechanism is executed, thereby achieving precise control of the foot end p of the fifth second auxiliary component 8.

[0085] Through multiple steps such as sensor data acquisition, trajectory planning, kinematic calculation, error processing and power system control, the trajectory of the walking robot's foot can be precisely controlled to improve the robot's adaptability and stability on complex terrain. Through closed-loop control, the system can adjust in real time to cope with changes in the external environment, reduce errors and improve walking efficiency.

[0086] Therefore, by comprehensively utilizing sensor data, advanced control algorithms and precise power system control, the performance and adaptability of walking robots in complex environments can be improved.

[0087] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A closed-chain leg mechanism of a walking robot, characterized in that: It includes the first three sub-components, the second three sub-components and the third three sub-components, the first two sub-components, the second two sub-components, the third two sub-components, the fourth two sub-components, the fifth two sub-components and a power system, wherein: The first three components are used as the body of the robot, and the fifth two components are used as the feet of the robot; One end of the first two sub-components is hinged to the first three sub-components through hinge c, and the other end is hinged to the second three sub-components and the third three sub-components through hinge f; one end of the second two sub-components is hinged to the first three sub-components through hinge a, and the other end is hinged to the third three sub-components through hinge d; one end of the third two sub-components is hinged to the first three sub-components through hinge b, and the other end is hinged to the second three sub-components through hinge g; One end of the fourth second sub-component is hinged to the third third sub-component through a hinge e, and the other end is hinged to one end of the fifth second sub-component through a hinge q; the other end of the fifth second sub-component is hinged to the second third sub-component through a hinge h, and the foot end p of the fifth second sub-component is a free end and in contact with the ground; The first three components are fixedly arranged at one side between hinge a and hinge b, and the power system is used to drive the first two components to rotate 360° around the first three components through hinge c.

2. The closed-chain leg mechanism of a walking robot according to claim 1, characterized in that: Also includes: A sensor system, arranged on the first three components, for collecting data of the external terrain environment; A control system is arranged on the first three components, and the control system is electrically connected to the power system and the sensor system respectively.

3. The closed-chain leg mechanism of the walking robot according to claim 2, characterized in that: The power system is any one of an internal combustion engine, an electric motor, a steam turbine and a hydraulic system.

4. The closed-chain leg mechanism of the walking robot according to claim 1, characterized in that: The first three sub-components, the second three sub-components and the third three sub-components are all triangular plate structures, and hinges are respectively installed at the three vertices of the triangular plate structure.

5. The closed-chain leg mechanism of a walking robot according to claim 1, characterized in that: The first second auxiliary component, the second second auxiliary component, the third second auxiliary component and the fourth second auxiliary component are all connecting rod structures.

6. The closed-chain leg mechanism of a walking robot according to claim 1, characterized in that: The fifth second auxiliary component is a triangular plate structure.

7. The closed-chain leg mechanism of a walking robot according to claim 1, characterized in that: Degrees of freedom of the closed-chain leg mechanism F The calculation expression is: F = 3 n - 2 P L - P H in: n is the number of active components, P L is the number of low pairs, P H is the number of high pairs.

8. The closed-chain leg mechanism of the walking robot according to claim 7, characterized in that: The movement trajectory of the foot end p of the fifth second auxiliary component is a smooth arc that first rises and then falls, with the bottom approaching a straight line and the top forming a smooth arc.

9. A foot end trajectory control method of a closed-chain leg mechanism of a walking robot using the method of claim 2, characterized in that: The foot end trajectory control method comprises the steps of: Step S 100 :The control system collects the spatial state data of the walking robot during movement and the environmental sensing data of the external terrain through the sensor system; Step S 200 : The control system plans the foot trajectory for different road conditions according to the environmental sensor data and leg mechanism parameters; Step S 300 : The control system performs kinematic calculations according to the foot end trajectory planning, obtains the calculated expected value of the foot end p of the fifth second auxiliary component, and converts it into a control signal of the power system to control the output power of the power system; Step S 400 :The control system receives the feedback value signal of the sensor system, calculates the error according to the expected value and feedback value of the power system, performs fuzzy PID processing on the error value, and outputs the control amount to realize the precise control of the rotation speed of the first and second auxiliary components; Step S 500 : Through the precise control of the power system, the movement of the leg mechanism is executed, thereby achieving precise control of the foot end p of the fifth second auxiliary component.

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