A modular linear drive humanoid robot leg system with six degrees of freedom

Abstract

A modular linear drive humanoid robot leg system with six degrees of freedom belongs to the technical field of humanoid robots. In order to solve the problem that the joints of the current humanoid robot are driven by rotating motors, resulting in a complex overall structure, a heavy weight and a low degree of bionics of the leg structure. The driving components at the leg joints of the present invention all adopt linear electric cylinders with a relatively light weight, and the overall structure is simple, which reduces the difficulty of manufacturing and designing the entire leg, and each driver does not need to be customized individually according to actual needs, which greatly reduces the difficulty of manufacturing. At the same time, the leg structure utilizes the principle of leverage and realizes the side swing, yaw and pitch movement of the leg, the pitch movement of the calf, and the pitch and yaw movement of the foot under the drive of six linear electric cylinders and the cooperation of ball bearings. The overall structure is simple, small in size, and light in weight, achieving the purpose of lightweight. The present invention is mainly used for the design of robot legs.

Description

Technical Field

[0001] The invention relates to a leg structure, in particular to a modular linear drive humanoid robot leg system with six degrees of freedom, belonging to the technical field of humanoid robots. Background Art

[0002] In the past, humanoid robots, as images in film and television works, gave people unlimited imagination. In today's world with rapid development of science and technology, this imagination is gradually becoming a reality. In today's world, countries are actively conducting research on humanoid robot technology. At present, humanoid robot technology has achieved many gratifying research results, but humanoid robot legs, as an important part of robot movement, still have many problems to be solved.

[0003] In order to make the humanoid robot have better dynamic performance, the movement form of each joint needs to be more flexible during design. However, due to different control parameters, the form, specification, size, etc. of each joint drive device vary greatly, resulting in high cost. At the same time, the joints of the human body are pulled by muscles, and the bionic degree of the joints driven by rotary motors is not high, resulting in a low degree of anthropomorphism in appearance. At the same time, the rotary motors that meet the joint requirements are large in size and mass, which will cause the overall robot mass to be too large and fail to achieve the purpose of lightweighting. Summary of the invention

[0004] In order to solve the problem that the joints of the current humanoid robot are driven by rotating motors, which leads to complex overall structure, heavy weight and low bionics degree of the leg structure, the present invention provides a modular linear drive humanoid robot leg system with six degrees of freedom. The degree of freedom of each joint is driven by an electric cylinder, and through a reasonable layout, the leg system has the characteristics of simple overall structure, compact layout, small size, light weight and high bionics degree.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A modular linear drive humanoid robot leg system with six degrees of freedom, comprising a hip joint structure with three degrees of freedom and a leg structure with three degrees of freedom, wherein the hip joint structure and the leg structure are hingedly connected via a hip joint pitch axis;

[0007] The hip joint structure comprises an upper hip joint base, a lower hip joint base, a hip joint universal joint, two side-swing yaw linear actuators and a pitch linear actuator; the upper hip joint base is arranged on one side of the lower hip joint base and is hingedly connected to the lower hip joint base through the hip joint universal joint; the two side-swing yaw linear actuators are symmetrically arranged on both sides of the upper hip joint base, the body of each side-swing yaw linear actuator is hingedly connected to the upper hip joint base through a ball bearing, and the driving end of the side-swing yaw linear actuator is hingedly connected to the upper hip joint base through a ball bearing. The leg structure is connected to the base below the hip joint, and the upper base of the hip joint and the lower base of the hip joint realize the side swing and yaw of the base below the hip joint through the coupling effect of two side swing and yaw linear actuators, thereby driving the side swing and yaw of the leg structure; the pitch linear actuator is arranged on the rear side of the leg structure, the body of the pitch linear actuator is connected to the leg structure through a bearing hinge, the driving end of the pitch linear actuator is connected to the base below the hip joint through a bearing hinge, and the leg structure performs a pitch action around the hip joint pitch axis under the drive of the pitch linear actuator;

[0008] The leg structure includes a thigh, a knee joint shaft, a calf, an ankle joint universal joint assembly, a foot, two ankle joint drivers, a knee joint linear driver and a four-bar crank rocker assembly; the top end of the thigh and the lower base of the hip joint are hinged together on the hip joint pitch axis, the bottom end of the thigh and the top end of the calf are rotationally connected through the knee joint shaft, and the bottom end of the calf and the foot are hinged through the ankle joint universal joint assembly; the knee joint linear driver and the four-bar crank rocker assembly are installed on the front side of the thigh, and drive the calf to pitch around the knee joint shaft, the two ankle joint drivers are symmetrically arranged on the left and right sides of the calf, and the foot realizes pitch and yaw movements under the coupling drive of the two ankle joint drivers.

[0009] Preferably, the hip joint universal joint comprises two vertically arranged and rotatable pins, namely, pin 1 arranged along the y-axis direction and pin 2 arranged along the z-axis direction.

[0010] Preferably, the hip joint upper base includes a circular mounting ring and a connecting support rod, one end of the connecting support rod is mounted on the outer ring wall of the circular mounting ring, the other end of the connecting support rod extends radially and is hinged to the two ends of the pin shaft 2 in the hip joint universal joint, and the hip joint upper base can rotate around the pin shaft 2.

[0011] Preferably, the lower base of the hip joint includes a top connecting seat, a bottom sleeve, a bottom connecting ear and two pin shafts three; the top connecting seat is installed above the bottom sleeve and is rotatably connected to the two ends of the pin shaft one in the hip joint universal joint; a pin shaft three is vertically installed on each side of the top connecting seat, and the two pin shafts three are coaxially arranged along the y-axis direction, and the driving end of the side swing yaw linear actuator is hinged on the pin shaft three through a ball bearing; the bottom connecting ear is installed on the bottom sleeve and extends obliquely downward, and the driving end of the pitch linear actuator is hinged on the bottom connecting ear through a bearing; the bottom sleeve is sleeved on the hip joint pitch axis and can rotate around the hip joint pitch axis.

[0012] Preferably, the thigh is provided with a top connecting seat, a bottom connecting seat, a front thigh connecting ear, a rear upper connecting ear and a rear lower connecting ear, the top end of the thigh is rotatably mounted on the two ends of the hip joint pitch axis through the top connecting seat, and the bottom end of the thigh is rotatably mounted on the two ends of the knee joint rotation axis through the bottom connecting seat; a receiving groove is provided on the front and rear sides of the thigh, the front thigh connecting ear is arranged in the receiving groove on the front side of the thigh and close to the upper position, the rear upper connecting ear and the rear lower connecting ear are longitudinally arranged in sequence in the receiving groove on the rear side of the thigh and close to the lower position; the knee joint linear drive 13 and the pitch linear drive are respectively arranged in the receiving grooves on the front and rear sides of the thigh; the body of the knee joint linear drive is connected to the front thigh connecting ear through a bearing, the driving end of the knee joint linear drive is connected to a hinge point of the four-bar crank rocker assembly through a bearing, and the body of the pitch linear drive is hinged to the rear upper connecting ear through a bearing.

[0013] Preferably, the ankle universal joint assembly includes an ankle universal joint and an ankle mounting seat, the ankle universal joint includes two vertically arranged and rotatable pins, namely a pin four arranged along the x-axis direction and a pin five arranged along the y-axis direction; the ankle mounting seat is fixedly mounted on the instep of the foot, the ankle universal joint is rotatably mounted on the ankle mounting seat through the pin five, and the ankle mounting seat and the foot can rotate around the pin five.

[0014] Preferably, the calf is provided with a top connecting sleeve, a bottom connecting seat and a pin shaft, the top end of the calf is sleeved on the knee joint shaft through the top connecting sleeve and can rotate around the knee joint shaft, the bottom end of the calf is installed at both ends of the pin shaft four in the ankle joint universal joint through the bottom connecting seat and can rotate around the pin shaft four; a receiving groove is respectively provided on the left and right sides of the calf, and the ankle joint driver is in the receiving groove; the pin shaft is inserted into the calf along the x-axis direction, the body end of the ankle joint driver is connected to the end of the pin shaft through a ball bearing, and the driving end of the ankle joint driver is connected to the bottom connecting seat through a ball bearing.

[0015] Preferably, the four-bar crank rocker assembly is composed of a knee joint link 1, a knee joint link 2, a front calf connecting ear and a bottom connecting seat of the thigh. One end of the knee joint link 1, one end of the knee joint link 2 and the driving end of the knee joint linear actuator are connected in series by a pin shaft. The other end of the knee joint link 1 passes through a vertical waist hole on the thigh and is hinged to the rear lower connecting ear; the front calf connecting ear is fixedly mounted on the top connecting sleeve, and the other end of the knee joint link 2 is hinged to the front calf connecting ear.

[0016] Preferably, the knee joint connecting rod 1 and the knee joint connecting rod 2 are both bent rods with a certain angle, and the knee joint connecting rod 1 and the knee joint connecting rod 2 are symmetrically arranged with the line connecting the hinge points of the two and the hinge points at the knee joint shaft as the axis.

[0017] Preferably, the roll yaw linear actuator, pitch linear actuator, ankle joint actuator and knee joint linear actuator are all electric cylinders.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The driving components at the leg joints of the present invention all use light-weight linear electric cylinders, and the overall structure is simple, which reduces the manufacturing and design difficulty of the entire leg, and each driver does not need to be customized individually according to actual needs, which greatly reduces the manufacturing difficulty. At the same time, the leg structure uses the lever principle and realizes the side swing, yaw and pitch movement of the leg, the pitch movement of the calf, and the pitch and yaw movement of the foot under the drive of six linear electric cylinders and the cooperation of ball bearings. The overall structure is simple, small in size, and light in weight, achieving the purpose of lightweight.

[0020] 2. The present invention is provided with accommodating grooves on the front and rear sides of the thigh for installing the pitch linear actuator and the knee joint linear actuator, and is provided with accommodating grooves on the left and right sides of the calf for installing two ankle joint actuators, which is similar to the traction of human leg muscles, and the entire leg layout is more compact and the appearance is more "humanized". BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are incorporated as part of this application and are used to provide a further understanding of the present invention.

[0022] Figure 1 The axonometric Figure 1 .

[0023] Figure 2 The axonometric Figure 2 .

[0024] Figure 3 It is the front view of the present invention.

[0025] Figure 4 It is a left view of the present invention.

[0026] Figure 5 It is the right side view of the present invention.

[0027] Figure 6 It is a rear view of the present invention.

[0028] Figure 7 It is a top view of the present invention.

[0029] Figure 8 Axonometric view of the hip joint structure.

[0030] Fig. 9 Axonometric view of the thigh.

[0031] Fig.10 It is a cross-sectional view of the four-link crank rocker assembly.

[0032] Fig.11 This is an axonometric view of the four-bar crank rocker assembly.

[0033] Fig.12 This is a schematic diagram of the structure connecting the calf and the foot.

[0034] Explanation of reference numerals: A-hip joint structure; B-leg structure; 1-hip joint upper base; 2-hip joint lower base; 3-hip joint universal joint; 4-side swing yaw linear actuator; 5-pitch linear actuator; 6-hip joint pitch axis; 7-thigh; 8-knee joint rotation axis; 9-calf; 10-ankle joint universal joint assembly; 11-foot; 12-ankle joint actuator; 13-knee joint linear actuator; 14-four-bar crank rocker assembly; 1-1-circular mounting ring; 1-2-connecting support rod; 2-1-top connecting seat; 2-2-bottom sleeve; 2-3-bottom Connecting ear; 2-4-pin shaft three; 3-1-pin shaft one; 3-2-pin shaft two; 7-1-top connecting seat; 7-2-bottom connecting seat; 7-3-front thigh connecting ear; 7-4-upper connecting ear on the back; 7-5-lower connecting ear on the back; 7-6-waist hole; 9-1-top connecting sleeve; 9-2-bottom connecting seat; 10-1-ankle joint universal joint; 10-2-ankle joint mounting seat; 10-1-1-pin shaft four; 10-1-2-pin shaft five; 14-1-knee joint connecting rod one; 14-2-knee joint connecting rod two; 14-3-front calf connecting ear. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0036] See also Figures 1 to 12 An embodiment of the present application provides a modular linear-drive humanoid robot leg system with six degrees of freedom, which includes a hip joint structure A with three degrees of freedom and a leg structure B with three degrees of freedom. The hip joint structure A and the leg structure B are hingedly connected through a hip joint pitch axis 6.

[0037] See also Figures 1 to 8 , the hip joint structure A is used to connect the leg structure B with the robot body, and can realize the three degrees of freedom of the leg structure B, namely the roll, yaw and pitch of the leg structure B. The hip joint structure A includes a hip joint upper base 1, a hip joint lower base 2, a hip joint universal joint 3, two roll and yaw linear actuators 4 and a pitch linear actuator 5; the hip joint upper base 1 is used to connect the hip joint with the robot body, the hip joint lower base 2 is used to connect the hip joint with the thigh, the hip joint upper base 1 is arranged on one side of the hip joint lower base 2, and is hinged to the hip joint lower base 2 through the hip joint universal joint 3; the two roll and yaw linear actuators 4 are symmetrically arranged on both sides of the hip joint upper base 1, and are located on the front and rear sides of the leg structure B, and the body of each roll and yaw linear actuator 4 is hinged to the hip joint through a ball bearing. On the upper base 1 of the joint, the driving end of the roll and yaw linear actuator 4 is connected to the lower base 2 of the hip joint through a ball bearing hinge. The roll and yaw of the lower base 2 of the hip joint are realized through the coupling action of the two roll and yaw linear actuators 4 between the upper base 1 of the hip joint and the lower base 2 of the hip joint, thereby driving the roll and yaw of the leg structure B; the pitch linear actuator 5 is arranged on the rear side of the leg structure B, the body of the pitch linear actuator 5 is connected to the leg structure B through a bearing hinge, and the driving end of the pitch linear actuator 5 is connected to the lower base 2 of the hip joint through a bearing hinge. Driven by the pitch linear actuator 5, the leg structure B performs a pitch movement around the hip joint pitch axis 6.

[0038] For further information, see Figure 8 The hip joint universal joint 3 includes two vertically arranged and rotatable pins, namely, a pin 3-1 arranged along the y-axis direction and a pin 3-2 arranged along the z-axis direction. Therefore, the hip joint universal joint 3 has two degrees of freedom, namely, one degree of freedom of rotation around the pin 3-1 (y-axis) and one degree of freedom of rotation around the pin 3-2 (z-axis), so as to realize the side swing and yaw of the leg structure B.

[0039] For further information, see Figure 7 The hip joint upper base 1 includes a circular mounting ring 1-1 and a connecting rod 1-2, one end of the connecting rod 1-2 is mounted on the outer ring wall of the circular mounting ring 1-1, and the other end of the connecting rod 1-2 extends radially and is hinged to the two ends of the pin shaft 2 3-2 in the hip joint universal joint 3. The hip joint upper base 1 can rotate around the pin shaft 2 3-2.

[0040] For further information, see Figure 6 The lower base 2 of the hip joint includes a top connecting seat 2-1, a bottom sleeve 2-2, a bottom connecting ear 2-3 and two pin shafts 3 2-4; the top connecting seat 2-1 is installed above the bottom sleeve 2-2, and is rotatably connected to the two ends of the pin shaft 3-1 in the hip joint universal joint 3 to ensure that the lower base 2 of the hip joint can rotate around the pin shaft 3-1; a pin shaft 3 2-4 is vertically installed on each side of the top connecting seat 2-1, and the two pin shafts 3 2-4 are coaxially arranged along the y-axis direction, and the side swing yaw straight The driving end of the linear driver 4 is connected to the pin shaft three 2-4 through a ball bearing hinge, and outputs torque to the lower base 2 of the hip joint through the pin shaft three 2-4; the bottom connecting ear 2-3 is installed on the bottom sleeve 2-2 and extends downward at an angle, and the driving end of the pitch linear driver 5 is connected to the bottom connecting ear 2-3 through a bearing hinge; the bottom sleeve 2-2 is sleeved on the hip joint pitch axis 6 and can rotate around the hip joint pitch axis 6, thereby realizing the rotational movement between the hip joint structure A and the leg structure B.

[0041] Furthermore, the roll yaw linear actuator 4 and the pitch linear actuator 5 are both electric cylinders to reduce the volume and mass at the hip joint.

[0042] In this embodiment, the leg system utilizes the lever principle and realizes the side swing and yaw movement of the leg under the coupling drive of two side swing and yaw linear actuators 4 and the cooperation of ball bearings, and realizes the pitch movement of the leg under the drive of the pitch linear actuator 5. The overall structure of the hip joint part is simple, the volume is small, and the weight is light, thus achieving the purpose of lightweight.

[0043] See also Figure 4 and Fig. 9 The leg structure B can realize one degree of freedom movement of the leg and two degrees of freedom movement of the foot, which are respectively the pitch movement of the knee joint, the pitch movement of the ankle joint and the yaw movement of the ankle joint; the leg structure B includes a thigh 7, a knee joint shaft 8, a calf 9, an ankle joint universal joint assembly 10, a foot 11, two ankle joint drivers 12, a knee joint linear driver 13 and a four-bar crank rocker assembly 14; the top end of the thigh 7 is hinged on the hip joint pitch shaft 6, the bottom end of the thigh 7 is rotationally connected to the top end of the calf 9 through the knee joint shaft 8, and the bottom end of the calf 9 is hinged to the foot 11 through the ankle joint universal joint assembly 10; the knee joint linear driver 13 and the four-bar crank rocker assembly 14 are installed on the front side of the thigh 7, and drive the calf 9 to pitch around the knee joint shaft 8, the two ankle joint drivers 12 are symmetrically arranged on the left and right sides of the calf 9, and the foot 11 realizes pitch and yaw movement under the coupling drive of the two ankle joint drivers 12.

[0044] For further information, see Fig. 9 The thigh 7 is provided with a top connecting seat 7-1, a bottom connecting seat 7-2, a front thigh connecting ear 7-3, a rear upper connecting ear 7-4 and a rear lower connecting ear 7-5. The top end of the thigh 7 is rotatably mounted on the two ends of the hip joint pitch axis 6 through the top connecting seat 7-1, and the bottom end of the thigh 7 is rotatably mounted on the two ends of the knee joint rotation axis 8 through the bottom connecting seat 7-2; a receiving groove is provided on the front and rear sides of the thigh 7, the front thigh connecting ear 7-3 is arranged in the receiving groove on the front side of the thigh 7, and is close to the upper position, the rear upper connecting ear 7-4 and the rear lower connecting ear The ears 7-5 are longitudinally arranged in sequence in the accommodating groove on the rear side of the thigh 7 and close to the lower position; the knee joint linear actuator 13 and the pitch linear actuator 5 are respectively arranged in the accommodating grooves on the front and rear sides of the thigh 7 to reduce the overall volume of the thigh part and make the layout more compact and anthropomorphic; the body of the knee joint linear actuator 13 is connected to the connecting ear 7-3 on the front side of the thigh through a bearing, and the driving end of the knee joint linear actuator 13 is connected to a hinge point of the four-bar crank rocker assembly 14 through a bearing, and the body of the pitch linear actuator 5 is hingedly connected to the connecting ear 7-4 on the rear side through a bearing.

[0045] For further information, see Fig.12 The ankle universal joint assembly 10 includes an ankle universal joint 10-1 and an ankle mounting seat 10-2. The ankle universal joint 10-1 includes two vertically arranged and rotatable pins, namely, a pin four 10-1-1 arranged along the x-axis direction and a pin five 10-1-2 arranged along the y-axis direction. Therefore, the ankle universal joint 10-1 has two degrees of freedom, namely, one degree of freedom rotating around the pin four 10-1-1 (x-axis direction) and one degree of freedom rotating around the pin five 10-1-2 (y-axis direction); the ankle mounting seat 10-2 is fixedly mounted on the instep of the foot 11, and the ankle universal joint 10-1 is rotatably mounted on the ankle mounting seat 10-2 through the pin five 10-1-2, and the ankle mounting seat 10-2 and the foot 11 can rotate around the pin five 10-1-2.

[0046] For further information, see Fig.12The calf 9 is provided with a top connecting sleeve 9-1, a bottom connecting seat 9-2 and a pin. The top end of the calf 9 is mounted on the knee joint shaft 8 through the top connecting sleeve 9-1 and can rotate around the knee joint shaft 8. The bottom end of the calf 9 is installed at both ends of the pin four 10-1-1 in the ankle joint universal joint 10-1 through the bottom connecting seat 9-2 and can rotate around the pin four 10-1-1; a receiving groove is respectively provided on the left and right sides of the calf 9, and the ankle joint driver 12 is in the receiving groove to reduce the overall volume of the calf 9 part, and the layout is more compact and anthropomorphic; the pin is inserted into the calf 9 along the x-axis direction, the body end of the ankle joint driver 12 is connected to the end of the pin through a ball bearing, and the driving end of the ankle joint driver 12 is connected to the bottom connecting seat 9-2 through a ball bearing.

[0047] For further information, see Fig.10 and Fig.11 The four-link crank rocker assembly 14 is composed of a knee joint connecting rod 1 14-1, a knee joint connecting rod 2 14-2, a calf front connecting ear 14-3 and a bottom connecting seat 7-2 of the thigh 7. One end of the knee joint connecting rod 1 14-1, one end of the knee joint connecting rod 2 14-2 and the driving end of the knee joint linear actuator 13 are connected in series by a pin shaft. The other end of the knee joint connecting rod 1 14-1 passes through the vertical waist hole 7-6 on the thigh 7 and is hinged to the rear lower connecting ear 7-5; the calf front connecting ear 14-3 is fixedly installed on the top connecting sleeve 9-1, and the other end of the knee joint connecting rod 2 14-2 is hinged to the calf front connecting ear 14-3.

[0048] Furthermore, the knee joint link 1 14-1 and the knee joint link 2 14-2 are both bent rods with a certain angle, and the longitudinal section shapes of the two are the same. The knee joint link 14-1 and the knee joint link 2 14-2 are symmetrically arranged with the line connecting the hinge points of the two and the hinge points at the knee joint shaft 8 as the axis.

[0049] Furthermore, the bending angle of the knee joint link 1 14 - 1 or the knee joint link 2 14 - 2 is an obtuse angle.

[0050] Furthermore, the knee joint connecting rod 1 14 - 1 and the knee joint connecting rod 2 14 - 2 are both bent outwards.

[0051] Furthermore, the ankle joint driver 12 and the knee joint linear driver 13 are both electric cylinders.

[0052] In this embodiment, the leg system utilizes the lever principle and realizes the pitch motion of the calf 9 around the knee joint rotation axis 8 under the drive of the knee joint linear driver 13 and the cooperation of the four-bar crank rocker assembly 14; the pitch and yaw motions of the foot are realized under the coupled drive of the two ankle joint drivers 12 and the cooperation of the ball bearings; at the same time, due to the layout between the pitch linear driver 5 and the knee joint linear driver 13 and the thigh 7 and the layout between the two ankle joint drivers 12 and the calf 9, the entire leg structure is simpler, smaller in size, more compact in layout and more anthropomorphic.

[0053] In this embodiment, the four-link crank rocker assembly 14 adopts a bionic design. Under the premise of meeting the joint movement speed, the output requirement of the knee joint linear actuator 13 can be reduced within a certain range of joint movement, and the length of the force arm of the knee joint linear actuator 13 driving the calf 9 is increased to reduce the output force of the knee joint linear actuator 13. In addition, the yaw linear actuator 4 and the ankle joint actuator 12 are both designed in parallel, and the output force of a single linear actuator is reduced to half, thereby reducing the mass of a single actuator, thereby achieving the purpose of lightweighting.

[0054] The working process of the present invention is further described below to further demonstrate the working principle and advantages of the present invention:

[0055] 1. The process of leg side swing movement:

[0056] See also Figure 7 and Figure 8 When the upper base 1 of the hip joint is connected to the fuselage and remains fixed, the telescopic rods of the two side swing yaw linear actuators 4 are synchronously extended out of the cylinder body and the extended lengths are the same, the telescopic rods generate the same thrust on the two ends of the lower base 2 of the hip joint, and the lower base 2 of the hip joint rotates around the pin shaft 3-1 based on the lever principle, and drives the leg structure to swing to the side of the fuselage, thereby realizing the freedom of the leg side swing.

[0057] 2. The process of leg yaw movement:

[0058] See also Figure 7 and Figure 8 When the telescopic rods of the two side swing yaw linear drives 4 extend out of the cylinder body to different lengths, the base 2 under the hip joint rotates around the pin shaft 2 3-2 under the coupling drive of the telescopic rods of the two electric cylinders. When the telescopic rod of the electric cylinder in front of the fuselage extends longer and the telescopic rod of the electric cylinder behind the fuselage extends shorter, the base 2 under the hip joint drives the leg structure to rotate clockwise. Otherwise, the base 2 under the hip joint drives the leg structure to rotate counterclockwise, thereby realizing the freedom of leg yaw.

[0059] 3. The process of leg pitching movement:

[0060] The telescopic rod of the pitch linear actuator 5 extends out of the cylinder body and generates thrust on the base 2 under the hip joint. The base 2 under the hip joint rotates around the hip joint pitch axis 6 and drives the leg structure to swing back and forth, thereby realizing the pitch freedom of the leg.

[0061] 4. The process of calf pitching movement:

[0062] See also Fig.10 and Fig.11 The telescopic rod of the knee joint linear actuator 13 extends out of the cylinder body and generates thrust on the ends of the knee joint link 14-1 and the knee joint link 2 14-2. The knee joint link 1 14-1 rotates around the hinge axis of the knee joint link 1 14-1 and the rear lower connecting ear 7-5, and drives one end of the knee joint link 2 14-2 to rotate. The other end of the knee joint link 2 14-2 drives the calf 9 to rotate around the knee joint rotation axis 8 through the front side connecting ear 14-3 of the calf, thereby realizing the pitching movement of the calf.

[0063] 5. The process of foot pitching movement:

[0064] See also Fig.12 The telescopic rods of the two ankle joint drivers 12 extend out of the cylinder body synchronously and to the same length, and the telescopic rods generate thrust on the two ends of the ankle joint mounting seat 10-2 and the foot, and the ankle joint mounting seat 10-2 and the foot rotate around the pin shaft 10-1-1 to realize the pitch movement of the foot.

[0065] 6. The process of foot swing movement:

[0066] See also Fig.12 The telescopic rods of the two ankle joint drivers 12 extend out of the cylinder body to different lengths. The telescopic rods generate thrust on the two ends of the ankle joint mounting seat 10-2 and the foot. The ankle joint mounting seat 10-2 and the foot rotate around the pin shaft five 10-1-2 and the pin shaft four 10-1-1 to realize the yaw movement of the foot.

[0067] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A modular linear drive humanoid robot leg system with six degrees of freedom, characterized in that: It comprises a three-degree-of-freedom hip joint structure (A) and a three-degree-of-freedom leg structure (B), wherein the hip joint structure (A) and the leg structure (B) are hinge-connected via a hip joint pitch axis (6); The hip joint structure (A) comprises an upper hip joint base (1), a lower hip joint base (2), a hip joint universal joint (3), two roll yaw linear actuators (4) and a pitch linear actuator (5); the upper hip joint base (1) is arranged on one side of the lower hip joint base (2) and is hingedly connected to the lower hip joint base (2) via the hip joint universal joint (3); the two roll yaw linear actuators (4) are symmetrically arranged on both sides of the upper hip joint base (1), the body of each roll yaw linear actuator (4) is hingedly connected to the upper hip joint base (1) via a ball bearing, and the driving end of the roll yaw linear actuator (4) is hingedly connected to the upper hip joint base (1) via a ball bearing. The leg structure (B) is connected to the base (2) below the hip joint. The upper base (1) of the hip joint and the base (2) below the hip joint are coupled to each other through two side swing and yaw linear actuators (4) to achieve the side swing and yaw of the base (2) below the hip joint, thereby driving the side swing and yaw of the leg structure (B). The pitch linear actuator (5) is arranged on the rear side of the leg structure (B). The body of the pitch linear actuator (5) is connected to the leg structure (B) through a bearing hinge. The driving end of the pitch linear actuator (5) is connected to the base (2) below the hip joint through a bearing hinge. The leg structure (B) performs a pitch motion around the hip joint pitch axis (6) driven by the pitch linear actuator (5). The leg structure (B) comprises a thigh (7), a knee joint shaft (8), a calf (9), an ankle joint universal joint assembly (10), a foot (11), two ankle joint drivers (12), a knee joint linear driver (13) and a four-bar crank rocker assembly (14); the top end of the thigh (7) and the lower base of the hip joint (2) are hingedly connected to the hip joint pitch axis (6), the bottom end of the thigh (7) and the top end of the calf (9) are rotationally connected via the knee joint shaft (8), The bottom end of the calf (9) is hingedly connected to the foot (11) via an ankle joint universal joint assembly (10); the knee joint linear actuator (13) and the four-link crank rocker assembly (14) are installed on the front side of the thigh (7) and drive the calf (9) to perform a pitching motion around the knee joint rotation axis (8); the two ankle joint actuators (12) are symmetrically arranged on the left and right sides of the calf (9); the foot (11) achieves pitching and yaw motions under the coupled drive of the two ankle joint actuators (12); The hip joint universal joint (3) comprises two vertically arranged and rotatable pins, namely a pin 1 (3-1) arranged along the y-axis direction and a pin 2 (3-2) arranged along the z-axis direction; The hip joint lower base (2) comprises a top connecting seat (2-1), a bottom sleeve (2-2), a bottom connecting ear (2-3) and two pin shafts (2-4); the top connecting seat (2-1) is mounted above the bottom sleeve (2-2) and is rotatably connected to the two ends of the pin shaft (3-1) in the hip joint universal joint (3); a pin shaft (2-4) is vertically mounted on each side of the top connecting seat (2-1), and the two pin shafts (2-4) are coaxially arranged along the y-axis direction, and the driving end of the roll yaw linear actuator (4) is hingedly connected to the pin shaft (2-4) via a ball bearing; the bottom connecting ear (2-3) is mounted on the bottom sleeve (2-2) and extends obliquely downward, and the driving end of the pitch linear actuator (5) is hingedly connected to the bottom connecting ear (2-3) via a bearing; the bottom sleeve (2-2) is sleeved on the hip joint pitch axis (6) and can rotate around the hip joint pitch axis (6); The thigh (7) is provided with a top connection seat (7-1), a bottom connection seat (7-2), a front thigh connection ear (7-3), a rear upper connection ear (7-4) and a rear lower connection ear (7-5); the top end of the thigh (7) is rotatably mounted on the two ends of the hip joint pitch axis (6) through the top connection seat (7-1); the bottom end of the thigh (7) is rotatably mounted on the two ends of the knee joint rotation axis (8) through the bottom connection seat (7-2); a receiving groove is provided on the front and rear sides of the thigh (7); the front thigh connection ear (7-3) is arranged in the receiving groove on the front side of the thigh (7) and close to the upper position; The rear upper connecting ear (7-4) and the rear lower connecting ear (7-5) are longitudinally arranged in sequence in the receiving groove on the rear side of the thigh (7) and close to the lower position; the knee joint linear actuator (13) and the pitch linear actuator (5) are respectively arranged in the receiving grooves on the front and rear sides of the thigh (7); the body of the knee joint linear actuator (13) is connected to the front thigh connecting ear (7-3) through a bearing, the driving end of the knee joint linear actuator (13) is connected to a hinge point of the four-bar crank rocker assembly (14) through a bearing, and the body of the pitch linear actuator (5) is hingedly connected to the rear upper connecting ear (7-4) through a bearing; The ankle joint universal joint assembly (10) comprises an ankle joint universal joint (10-1) and an ankle joint mounting seat (10-2); the ankle joint universal joint (10-1) comprises two vertically arranged and rotatable pins, namely a pin four (10-1-1) arranged along the x-axis direction and a pin five (10-1-2) arranged along the y-axis direction; the ankle joint mounting seat (10-2) is fixedly mounted on the instep of the foot (11); the ankle joint universal joint (10-1) is rotatably mounted on the ankle joint mounting seat (10-2) via the pin five (10-1-2); the ankle joint mounting seat (10-2) and the foot (11) can rotate around the pin five (10-1-2).

2. A modular linear drive humanoid robot leg system with six degrees of freedom according to claim 1, characterized in that: The hip joint upper base (1) comprises a circular mounting ring (1-1) and a connecting rod (1-2), one end of the connecting rod (1-2) being mounted on the outer ring wall of the circular mounting ring (1-1), and the other end of the connecting rod (1-2) extending radially and being hingedly connected to the two ends of the second pin (3-2) in the hip joint universal joint (3), so that the hip joint upper base (1) can rotate around the second pin (3-2).

3. A modular linear drive humanoid robot leg system with six degrees of freedom according to claim 2, characterized in that: The calf (9) is provided with a top connection sleeve (9-1), a bottom connection seat (9-2) and a pin six. The top end of the calf (9) is sleeved on the knee joint shaft (8) through the top connection sleeve (9-1) and can rotate around the knee joint shaft (8). The bottom end of the calf (9) is installed at both ends of a pin four (10-1-1) in the ankle joint universal joint (10-1) through the bottom connection seat (9-2) and can rotate around the pin four (10-1-1). The calf (9) is provided with a receiving groove on each of the left and right sides, and the ankle joint driver (12) is located in the receiving groove. The pin six is ​​inserted into the calf (9) along the x-axis direction. The body end of the ankle joint driver (12) is connected to the end of the pin through a ball bearing, and the driving end of the ankle joint driver (12) is connected to the ankle joint universal joint (10-1) through a ball bearing.

4. The modular linear drive humanoid robot leg system with six degrees of freedom according to claim 3, characterized in that: The four-link crank rocker assembly (14) is composed of a knee joint connecting rod 1 (14-1), a knee joint connecting rod 2 (14-2), a calf front connecting ear (14-3) and a bottom connecting seat (7-2) of a thigh (7); one end of the knee joint connecting rod 1 (14-1), one end of the knee joint connecting rod 2 (14-2) and a driving end of a knee joint linear actuator (13) are connected in series by a pin shaft; the other end of the knee joint connecting rod 1 (14-1) passes through a waist hole (7-6) vertically opened on the thigh (7) and is hingedly connected to the rear lower connecting ear (7-5); the calf front connecting ear (14-3) is fixedly mounted on the top connecting sleeve (9-1), and the other end of the knee joint connecting rod 2 (14-2) is hingedly connected to the calf front connecting ear (14-3).

5. The modular linear drive humanoid robot leg system with six degrees of freedom according to claim 4, characterized in that: The knee joint connecting rod 1 (14-1) and the knee joint connecting rod 2 (14-2) are both bent rods with a certain angle. The knee joint connecting rod 1 (14-1) and the knee joint connecting rod 2 (14-2) are symmetrically arranged with the line connecting their hinge points and the hinge point at the knee joint shaft (8) as the axis.

6. The modular linear drive humanoid robot leg system with six degrees of freedom according to claim 1, characterized in that: The yaw linear drive (4), pitch linear drive (5), ankle joint drive (12) and knee joint linear drive (13) are all electric cylinders.

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