Biped mobile robot
By using a 4-UPU+2-P series-parallel hybrid mechanism and six independently controlled telescopic branch chains in the bipedal mobile robot, the problem of complex mechanisms, multiple driving and inefficient walking in the prior art is solved, and efficient and flexible walking ability is achieved.
Patent Information
- Application Number
- CN202510385711.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-29
- Publication Date
- 2025-06-10
AI Technical Summary
The existing bipedal mobile robot mechanism is complex, with a large number of driving and an inefficient walking method.
The 4-UPU+2-P series-parallel hybrid mechanism is adopted to switch dynamically and statically and alternately through six independently controlled telescopic branch chains, which restricts the platform to always maintain a level, realizing the "up + down" walking mode.
Reduces the number of drives, reduces control difficulty and cost, improves walking efficiency, and can adapt to irregular terrain.
Smart Images
Figure CN120117068A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of mobile robots, and particularly to a bipedal mobile robot. Background Art
[0002] At present, there are many dangerous and complex environments that are not suitable or even inaccessible for humans, such as search and rescue after natural disasters, battlefield reconnaissance, etc. With the rapid development of robot technology, mobile robots play important roles in fields such as post-disaster rescue and military reconnaissance, and can replace humans to complete many high-difficulty, high-risk and extreme environment tasks. Mobile robots mainly include legged robots, wheeled robots, tracked robots, and wheel-leg composite robots. Legged robots are relatively more flexible than other robots, and among legged robots, bipedal mobile robots have stronger terrain adaptability and a larger activity range.
[0003] Regarding the structural design of bipedal mobile robots based on parallel mechanisms, there are many research examples at home and abroad. Waseda University used two Stewart parallel structures as the legs of a bipedal mobile robot respectively, and designed the WL-16RIV mobile robot, which demonstrated excellent walking and load-carrying capabilities and was applicable to various scenarios. Wang Hongbo designed a bipedal parallel leg mobile robot based on two 3-SPU parallel mechanisms and applied it to the field of assisting the elderly and the disabled. Qi Kaicheng used two 3-UrPS parallel mechanisms as the leg mechanisms of a bipedal mobile robot respectively, and solved the problems of single degree of freedom and driving input by changing the selection of driving pairs.
[0004] However, the above existing bipedal mobile robots all use two parallel mechanisms as the legs of the bipedal mobile robot respectively to complete the alternating movement of the two legs and the platform. Such designs all require two parallel mechanisms and a relatively large number of drives, and the walking mode is relatively inefficient and complex. Summary of the Invention
[0005] To solve the problems in the prior art that bipedal mobile robots have more mechanisms and drives and a relatively complex walking mode, the present invention proposes a bipedal mobile robot.
[0006] The technical solution of the present invention is realized as follows: A bipedal mobile robot, comprising: a first top platform, a second top platform, a first foot bottom plate, a second foot bottom plate, and six telescopic chains with independently controlled driving pairs as moving pairs. A first telescopic chain and a second telescopic chain are hinged in parallel between one side of the first top platform and one side of the first foot bottom plate. A third telescopic chain is connected between the other side of the first foot bottom plate and one side of the second top platform. A fourth telescopic chain and a fifth telescopic chain are hinged in parallel between the other side of the second top platform and one side of the second foot bottom plate. A sixth telescopic chain is connected between the other side of the second foot bottom plate and the other side of the first top platform; The height and length of the first top platform are greater than those of the second top platform. The first foot plate and the second foot plate are located in the same plane. The initial lengths of the first telescopic chain and the second telescopic chain are the same and slightly greater than that of the sixth telescopic chain, and are greater than the fourth telescopic chain and the fifth telescopic chain with the same initial length. The third telescopic chain and the fourth telescopic chain are similar in length. The third telescopic chain and the sixth telescopic chain are two P chains, and the remaining four telescopic chains are UPU chains. Each UPU chain has two pairs of parallel rotating pairs. The six telescopic chains constrain the first top platform and the second top platform to always remain horizontal. In the non - moving state, release the moving pairs of the six telescopic chains. The first top platform adjusts its distance from the second top platform by extending or shortening the first telescopic chain, the second telescopic chain, and the sixth telescopic chain by the same length. The second top platform adjusts its distance from the first foot plate and the second foot plate by extending or shortening the third telescopic chain, the fourth telescopic chain, and the fifth telescopic chain by the same length. In the moving state, when the second foot plate touches the ground, lock the moving pairs of the four UPU chains. The third telescopic chain shortens and the sixth telescopic chain elongates, driving the first top platform and the first foot plate to lift. Lock the moving pairs of the two P chains and release the moving pairs of the four UPU chains. The first telescopic chain, the second telescopic chain, the fourth telescopic chain, and the fifth telescopic chain extend and contract by different lengths respectively, driving the first foot plate and the second top platform to move. Lock the moving pairs of the four UPU chains and release the moving pairs of the two P chains. The third telescopic chain elongates and the sixth telescopic chain shortens, driving the first top platform and the first foot plate to descend. When the first foot plate touches the ground, the third telescopic chain elongates and the sixth telescopic chain shortens, driving the second top platform and the second foot plate to lift. Lock the moving pairs of the two P chains and release the moving pairs of the four UPU chains. The first telescopic chain, the second telescopic chain, the fourth telescopic chain, and the fifth telescopic chain extend and contract by different lengths respectively, driving the second foot plate and the first top platform to move. Lock the moving pairs of the four UPU chains and release the moving pairs of the two P chains. The third telescopic chain shortens and the sixth telescopic chain elongates, driving the second top platform and the second foot plate to descend, completing the movement of one gait cycle, and repeating the gait cycle movement.
[0007] Preferably, a second infrared sensor and an angle sensor are provided at the front end of the second top platform, and are respectively transmitted to the central controller. The central controller is respectively transmitted to the controllers of the six telescopic chains. In the non - moving state, the height of the obstacle is measured. The central controller controls the telescopic distance of the third telescopic chain, the fourth telescopic chain, and the fifth telescopic chain through the data fed back by the second infrared sensor and the angle sensor, so as to ensure the obstacle - crossing ability of the first foot plate and the second foot plate. At the center of the bottom of the first top platform, a first infrared sensor is provided. The first infrared sensor transmits data to the central controller to measure the distance between the first top platform and the second top platform in the non-moving state. The central controller controls the telescopic distances of the first telescopic chain, the second chain, and the sixth chain according to the data fed back by the first infrared sensor to ensure that the first top platform and the second top platform do not interfere with each other during movement.
[0008] Preferably, the six telescopic chains are respectively set as independent servo electric cylinders. The two ends of the four UPU chains are respectively connected by Hooke joints. The Hooke joint includes a rotating pair base, a first rotating pair, a rotating sleeve, a clamping seat, and a second rotating pair. A connecting hole is provided on the rotating pair base for connecting with the first top platform or the second top platform or the first foot board or the second foot board. One end of the first rotating pair is connected to the rotating pair base through a bearing, and the other end extends into the rotating sleeve from the bottom end and is fixed on the rotating sleeve through a locking screw. Two clamping seats are fixed side by side at the top end of the rotating sleeve. The second rotating pair is connected to the two clamping seats through bearings. The axis of the first rotating pair and the axis of the second rotating pair are perpendicular to each other. The second rotating pair is fixedly connected to the moving pair of any one UPU chain.
[0009] The beneficial effects of the present invention are as follows: The biped mobile robot of the present invention adopts a 4-UPU+2-P series-parallel hybrid mechanism as the main body, and at the same time uses the first top platform, the second top platform, the first foot board, and the second foot board to cooperate and connect. By independently controlling the locking and telescopic lengths of the telescopic chains, the dynamic and static switching and alternating movement are carried out, and the first platform and the second platform are constrained to always remain horizontal. Only six telescopic chains are used in total, and each telescopic chain is independently driven. According to the "up+down" walking mode, the robot can walk, and has good adaptability to terrains such as irregular steps, gullies, and winding turns.
[0010] Compared with the existing biped mobile robots, the present invention only adds a second top platform, and a single parallel mechanism can be used as two legs. Compared with traditional biped mobile robots, only each telescopic chain has its own drive, so the required number of drives is greatly reduced, the control difficulty and control cost are reduced, and the overall weight is reduced. At the same time, the existence of two lockable P chains ensures that the first top platform and the second foot board, and the second top platform and the first foot board can form a component at any time. In the moving state, the two components of the biped mobile robot realize dynamic and static switching, and the two complete the alternating movement of the two feet through the elongation and shortening of the four UPU chains, realizing the "up+down" walking action and improving the walking efficiency. Description of the Drawings
[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0012] Figure 1 Schematic diagram of the overall structure of the biped mobile robot of the present invention; Figure 2 Schematic diagram of the structure of the first telescopic chain of the present invention; Figure 3 Schematic diagram of the structure of the third telescopic chain of the present invention; Figure 4 Schematic diagram of the structure of the Hooke joint of the present invention; Figure 5 Schematic diagram of the motion of a gait cycle of the biped mobile robot of the present invention during movement; Figure 6 Schematic diagram of the motion of a gait cycle of the biped mobile robot of the present invention when climbing stairs; Figure 7 is Figure 6 Schematic diagram of obstacle measurement shown; Figure 8 Schematic diagram of the motion of a gait cycle of the biped mobile robot of the present invention during turning.
[0013] In the figure: 1. First top platform; 2. Second top platform; 3. First foot bottom plate; 4. Second foot bottom plate; 5. UPU chain; 6. P chain; 7. Hooke joint; 8. Servo cylinder; 51. First telescopic chain; 52. Second telescopic chain; 53. Fourth telescopic chain; 54. Fifth telescopic chain; 61. Third telescopic chain; 62. Sixth telescopic chain; 71. Rotating pair base; 72. First rotating pair; 73. Rotating sleeve; 74. Clamping seat; 75. Second rotating pair. Detailed implementation manners
[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.
[0015] Embodiment: As Figures 1 to 3A bipedal mobile robot shown in the figure includes: a first top platform 1, a second top platform 2, a first foot bottom plate 3, a second foot bottom plate 4, and six telescopic chains with independent control as moving pairs, four UPU chains 5 and two P chains 6. A first telescopic chain 51 and a second telescopic chain 52 are respectively hinged between one side of the first top platform 1 and one side of the first foot bottom plate 3. A third telescopic chain 61 is connected between the other side of the first foot bottom plate 3 and one side of the second top platform 2. A fourth telescopic chain 53 and a fifth telescopic chain 54 are respectively hinged between the other side of the second top platform 2 and one side of the second foot bottom plate 4. A sixth telescopic chain 62 is connected between the other side of the second foot bottom plate 4 and the other side of the first top platform 1. The height and length of the first top platform 1 are greater than those of the second top platform 2. The first foot bottom plate 3 and the second foot bottom plate 4 are located in the same plane. The initial lengths of the first telescopic chain 51 and the second telescopic chain 52 are the same and slightly greater than the initial length of the sixth telescopic chain 62, and are greater than the initial lengths of the fourth telescopic chain 53 and the fifth telescopic chain 54 with the same initial length. The fourth telescopic chain is similar in length to the third telescopic chain 61. The four UPU chains are the first telescopic chain 51, the second telescopic chain 52, the fourth telescopic chain 53, and the fifth telescopic chain 54. The two P chains are the third telescopic chain 61 and the sixth telescopic chain 62. Each UPU chain has two pairs of parallel rotating pairs. The six telescopic chains constrain the first top platform and the second top platform to always remain horizontal.
[0016] In the non-mobile state, release the moving pairs of the six telescopic chains. The first top platform 1 adjusts the distance between the first top platform 1 and the second top platform 2 by the elongation and shortening of the first telescopic chain 51, the second telescopic chain 52, and the sixth telescopic chain 61. The second top platform 2 adjusts the distance between the second top platform 2 and the first foot bottom plate and the second foot bottom plate by the elongation and shortening of the third telescopic chain 62, the fourth telescopic chain 53, and the fifth telescopic chain 54.
[0017] Such as Figures 2 to 4As shown, each of the six telescopic chains is provided with an independent servo cylinder. The two ends of the four UPU chains 5 are respectively hinged by Hooke joints 7. The Hooke joint 7 includes a rotating pair base 71, a first rotating pair 72, a rotating sleeve 73, a clamping seat 74, and a second rotating pair 75. A connecting hole is provided on the rotating pair base 71 for connecting with the first top platform 1 or the second top platform 2 or the first foot bottom plate 3 or the second foot bottom plate 4. One end of the first rotating pair 72 is connected to the rotating pair base 71 through a bearing, and the other end extends into the rotating sleeve 73 from the bottom end and is fixed on the rotating sleeve 73 by a locking screw. Two clamping seats 74 are fixedly arranged in parallel at the top end of the rotating sleeve 73. The second rotating pair 75 is connected to the two clamping seats 74 through a bearing. The axis of the first rotating pair 72 and the axis of the second rotating pair 75 are perpendicular to each other. The second rotating pair 75 is fixedly connected to the moving pair in the UPU chain 5. The structure of the Hooke joint is used to achieve rotations in different directions, and the telescopic chains are used to achieve telescoping, enabling the biped mobile robot to walk and turn.
[0018] A second infrared sensor and an angle sensor are arranged at the front end of the second top platform and are respectively transmitted to the central controller. The central controller is respectively transmitted to the controllers of the six telescopic chains. When in the non-moving state, the height of the obstacle is measured. The central controller controls the telescoping distances of the third telescopic chain, the fourth telescopic chain, and the fifth telescopic chain through the data fed back by the second infrared sensor and the angle sensor to ensure the obstacle-crossing ability of the first foot bottom plate and the second foot bottom plate. A first infrared sensor is arranged at the center of the bottom of the first top platform. The first infrared sensor is transmitted to the central controller. When in the non-moving state, the distance between the first top platform and the second top platform is measured. The central controller controls the telescoping distances of the first telescopic chain, the second chain, and the sixth chain through the data fed back by the first infrared sensor to ensure that the first top platform and the second top platform do not interfere with each other during movement. The measurement methods of the first infrared sensor, the second infrared sensor, and the angle sensor and the control method of the central controller in this application adopt conventional methods and are existing devices.
[0019] Walking state of the biped mobile robot: As Figure 5 shown, when in the moving state, the second foot bottom plate 2 touches the ground, the moving pairs of the four UPU chains are locked, the third telescopic chain 61 shortens, and the sixth telescopic chain 62 elongates, driving the first top platform 1 and the first foot bottom plate 3 to lift up ( Figure 5 a); the moving pairs of the two P chains 6 are locked and the moving pairs of the four UPU chains 5 are released. The first telescopic chain 51 of the four UPU chains 5 first shortens and then elongates, the second telescopic chain 52 elongates, and the fourth telescopic chain 53 and the fifth telescopic chain 54 elongate, driving the first foot bottom plate 3 and the second top platform 2 to move forward ( Figure 5b); Lock the moving pairs of the four UPU linkages 5 and release the moving pairs of the two P linkages 6. The third telescopic linkage 61 extends and the sixth telescopic linkage 62 contracts, driving the first top platform 1 and the first foot plate 3 to descend ( Figure 5 c); The first foot plate 1 touches the ground. The third telescopic linkage 61 extends and the sixth telescopic linkage 62 contracts, driving the second top platform 2 and the second foot plate 4 to lift, completing the dynamic / static switching of the first foot plate 3 and the second foot plate 4 ( Figure 5 d); Lock the moving pairs of the two P linkages 6 and release the moving pairs of the four UPU linkages 5. The first telescopic linkage 51 contracts and then extends, the second telescopic linkage 52 contracts and then extends, the fourth telescopic linkage 53 and the fifth telescopic linkage 54 contract and then extend, driving the second foot plate 4 and the first top platform 1 forward ( Figure 5 e); Lock the moving pairs of the four UPU linkages 5 and release the moving pairs of the two P linkages 6. The third telescopic linkage 61 contracts and the sixth telescopic linkage 62 extends, driving the second top platform 2 and the second foot plate 4 to descend ( Figure 5 f), completing the movement of one gait cycle. Repeating the gait cycle movement can complete the flat-ground walking action of the robot. In the walking state of the robot, the backward mode is the same as the forward mode.
[0020] Stair-climbing state of the biped mobile robot: As Figure 6 and Figure 7 shown, it is a schematic diagram of the movement of one gait cycle of the biped mobile robot climbing stairs in this application. The initial state of the biped mobile robot is that the first foot plate 3 and the second foot plate 4 are in the supporting state. The second infrared sensor and the angle sensor cooperate. As Figure 7 described, the second infrared sensor measures the distance l 1 and l 2 , and the angle sensor measures the angles θ 1 and θ 2 . The central controller uses the detected θ 2 - θ 1 , l 1 and l 2 , and according to the cosine theorem, measures the height of the step or obstacle h , and controls the third telescopic linkage 61, the fourth telescopic linkage 53 and the fifth telescopic linkage 54 to extend by a length greater than h to reserve enough height for lifting the leg to climb the step or cross the obstacle.
[0021] As Figure 6As shown, the second foot sole plate 4 touches the ground. When climbing stairs, the moving pairs of the four UPU linkages 5 are locked. The central controller controls according to the height of the stairs. The third telescopic linkage 61 shortens, and the sixth telescopic linkage 62 elongates, driving the first foot sole plate 3 and the first top platform 1 to lift to a height higher than the stairs ( Figure 6 a); Lock the two P linkages 6, drive the moving pairs of the four UPU linkages 5. The first telescopic linkage 51 first shortens and then elongates, and the second telescopic linkage 52, the fourth telescopic linkage 53, and the fifth telescopic linkage 54 elongate by different lengths, driving the first foot sole plate 3 and the second top platform 2 to move forward above the first step. Lock the moving pairs of the four UPU linkages 5. The third telescopic linkage 61 elongates, and the sixth telescopic linkage 62 shortens, driving the first foot sole plate 3 and the first top platform 1 to descend onto the first step ( Figure 6 b); The first foot sole plate 3 touches the ground. The third telescopic linkage 61 elongates, and the sixth telescopic linkage 62 shortens, driving the second foot sole plate 4 and the first top platform 1 to lift to a height higher than the stairs, completing the alternation of the first foot sole plate 3 and the second foot sole plate 4 ( Figure 6 c); Lock the two P linkages 6, drive the moving pairs of the four UPU linkages 5, and control the first telescopic linkage 51, the second telescopic linkage 52, the fourth telescopic linkage 53, and the fifth telescopic linkage 54 to first shorten and then elongate by different lengths, driving the second foot sole plate 3 and the first top platform 1 to move forward above the second step. Lock the moving pairs of the four UPU linkages 5. The third telescopic linkage 61 shortens, and the sixth telescopic linkage 62 elongates, driving the second foot sole plate 3 and the second top platform 2 to descend onto the second step ( Figure 6 d). Thus, the biped mobile robot completes the up - step movement within a gait cycle in the "up + down" walking mode. The remaining steps can be completed according to this gait cycle for the up - step process.
[0022] The state of the biped mobile robot when crossing a gully: The actions of the biped mobile robot in this application for crossing a gully are similar to those for climbing stairs. When an obstacle is detected and the span of the gully is less than the distance that the biped mobile robot can cross, after the second infrared sensor detects the height of the gully, the movement of the biped mobile robot crossing the gully refers to the walking motion state; when the span of the gully is greater than the distance that the biped mobile robot can cross, the movement of the biped mobile robot crossing the gully refers to the climbing - stairs motion state. The states of the first foot sole plate and the second foot sole plate are as follows: first, move the first foot sole plate into the gully, the second foot sole plate directly crosses the gully, and finally the first foot sole plate gets out of the gully; when the span of the gully is much greater than the distance that the biped mobile robot can cross, the movement of the biped mobile robot crossing the gully refers to the climbing - stairs motion state. The states of the first foot sole plate and the second foot sole plate are as follows: first, move the first foot sole plate into the gully, the second foot sole plate advances in the gully, and they alternate in this way, and finally the first foot sole plate and the second foot sole plate get out of the gully.
[0023] Turning and walking state of a bipedal mobile robot: like Figure 8 As shown, a motion diagram of a gait cycle of the bipedal mobile robot of the present application when turning. During the turning process of the bipedal mobile robot, the second foot plate 2 touches the ground, the moving pairs of the four UPU branches 5 are locked, the moving pairs of the third telescopic branch chain 61 are shortened, and the moving pairs of the sixth telescopic branch chain 62 are extended, driving the first foot plate 3 and the first top platform 1 to lift; the moving pairs of the two P branches 6 are locked, and the moving pairs of the four UPU branches 5 are released. The moving pairs of the first telescopic branch chain 51 and the fourth telescopic branch chain 53 are extended by the same length, and the moving pairs of the second telescopic branch chain 52 and the fifth telescopic branch chain 54 are shortened by the same length, driving the first foot plate 3 and the second top platform 2 to rotate to the maximum angle, as shown in FIG. Figure 8 As shown in a; the first telescopic branch chain 51 is shortened first and then extended, and the second telescopic branch chain 52, the fourth telescopic branch chain 53 and the fifth telescopic branch chain 54 are extended to different lengths, driving the first foot plate 3 and the second top platform 2 forward, locking the driving pairs of the four UPU branch chains 5, the moving pair of the third telescopic branch chain 61 is extended, and the moving pair of the sixth telescopic branch chain 62 is shortened, driving the first foot plate 3 and the first top platform 1 to descend, as shown in FIG. Figure 8 As shown in b; the first foot plate 3 touches the ground, the moving pair of the third telescopic branch chain 61 extends, and the moving pair of the sixth telescopic branch chain 62 shortens, driving the second foot plate 4 and the second top platform 2 to lift up, completing the alternation of the first foot plate 3 and the second foot plate 4, locking the moving pairs of the two P branches 6, the moving pairs of the first telescopic branch chain 51 and the fourth telescopic branch chain 53 shorten the same length, and the moving pairs of the second telescopic branch chain 52 and the fifth telescopic branch chain 54 extend the same length, driving the second foot plate 4 and the first top platform 1 to rotate to the maximum angle, as shown in FIG. Figure 8 c; the first telescopic branch chain 51, the second telescopic branch chain 52, the fourth telescopic branch chain 53, and the fifth telescopic branch chain 54 are first shortened and then extended to different lengths, driving the second foot sole plate 4 and the first top platform 1 forward; the moving pairs of the four UPU branch chains 5 are locked, the moving pair of the third telescopic branch chain 61 is shortened, and the moving pair of the sixth telescopic branch chain 62 is extended, driving the second foot sole plate 4 and the second top platform 2 to descend, as shown in FIG. Figure 8 d. So far, the bipedal mobile robot has completed a turning movement within a gait cycle in an "up + down" walking mode. The remaining turning angle is cycled according to this gait until the first and second sole plates are turned to walk out of the curve. The subsequent movement is as follows Figure 8 e and 8f.
[0024] The specific way of dynamic / static switching during the movement of the biped mobile robot is as follows: After the first top platform and the first foot bottom plate are lifted, and locked and constrained by two P chains, the first top platform and the second foot bottom plate form a component to become the static platform, and the first foot bottom plate and the second top platform form a component to become the dynamic platform, completing movement and turning; After the first top platform and the first foot bottom plate descend and the second top platform and the second foot bottom plate are lifted, and locked and constrained by two P chains, the first top platform and the second foot bottom plate form a component to become the dynamic platform, and the first foot bottom plate and the second top platform form a component to become the static platform, completing dynamic / static switching and performing movement and turning. In addition, in addition to the constraints of the two P chains, since the four UPU chains will also form constraints on the dynamic platform, specifically restricting two rotational degrees of freedom of the dynamic platform, therefore, the biped mobile robot only has omnidirectional translational degrees of freedom and rotational degrees of freedom around the vertical direction.
[0025] There are 6 degrees of freedom in the actual space, including 3 translational degrees of freedom and 3 rotational degrees of freedom. In this application, four UPU chains are used to constrain the rotational degrees of freedom. Each UPU chain is composed of two parallel first rotational pairs, two parallel second rotational pairs, and one translational pair. According to the screw theory, two parallel rotational pairs can be equivalent to one rotational pair and one translational pair. Then each UPU chain has 5 degrees of freedom, including 3 translational degrees of freedom and 2 rotational degrees of freedom. The directions of the rotational degrees of freedom constrained by each UPU chain are different, but the rotational degrees of freedom constrained by the four UPU chains are all within the plane of the dynamic platform. Therefore, the degrees of freedom of the dynamic platform are only 4, namely 3 translational degrees of freedom and one rotational degree of freedom around the normal direction of the dynamic platform plane, and the first platform and the second platform always remain horizontal.
[0026] The reference book for screw theory is Advanced Spatial Mechanisms, pages p2 - p81.
[0027] The walking state of the biped mobile robot is described by taking specific parameters as an example: It is set that the first top platform 1 and the second top platform 2 are square. The length of the first top platform is 200 mm, the length of the second top platform 2 is 100 mm. The sizes of the first foot bottom plate 3 and the second foot bottom plate 4 are the same, with a length of 28 mm and a width of 40 mm. The telescopic ranges of the first telescopic chain 51, the second telescopic chain 52, and the sixth telescopic chain 62 are [150 mm, 300 mm]. The telescopic ranges of the third telescopic chain 61, the fourth telescopic chain 53, and the fifth telescopic chain 54 are [100 mm, 200 mm]. In the initial state, the vertical distance between the first top platform 1 and the first foot bottom plate, that is, the length of the sixth telescopic chain, is 170 mm, and the vertical distance between the second top platform 2 and the first foot bottom plate, that is, the length of the third telescopic chain, is 120 mm.
[0028] The specific changes of the four UPU linkages when the biped mobile robot walks under the above parameters. Initially, the displacements of the first foot sole plate and the second foot sole plate are 0. After the first top platform 1 and the first foot sole plate 3 are lifted, the moving pairs of the two P linkages 6 are locked. The first telescopic linkage 51 shortens from 180 mm to 170 mm and then extends to 190 mm, the second telescopic linkage 52 extends from 180 mm to 270 mm, and the fourth telescopic linkage 53 and the fifth telescopic linkage 54 extend from 120 mm to 190 mm, driving the first foot sole plate 3 and the second top platform 2 to move forward from 0 mm to 150 mm; the moving pairs of the four UPU linkages are locked, the third telescopic linkage 61 extends, and the sixth telescopic linkage 62 shortens, driving the first top platform 1 and the first foot sole plate 3 to descend; the first foot sole plate 3 touches the ground, the third telescopic linkage 61 extends, and the sixth telescopic linkage 62 shortens, driving the second top platform 2 and the second foot sole plate 4 to lift. At this time, the alternation of the first foot sole plate 3 and the second foot sole plate 4 is completed; the moving pairs of the two P linkages 6 are locked and the moving pairs of the four UPU linkages 5 are released. The first telescopic linkage 51 shortens from 190 mm to 170 mm and then extends to 270 mm, the second telescopic linkage 52 shortens from 270 mm to 170 mm and then extends to 190 mm, and the fourth telescopic linkage 53 and the fifth telescopic linkage 54 shorten from 190 mm to 120 mm and then extend back to 190 mm, driving the second foot sole plate 4 and the first top platform 1 to move forward from -150 mm to 150 mm; the moving pairs of the four UPU linkages 5 are locked and the moving pairs of the two P linkages 6 are released. The third telescopic linkage 61 shortens, and the sixth telescopic linkage 62 extends, driving the second top platform 2 and the second foot sole plate 4 to descend, completing the movement of one gait cycle. Repeating the gait cycle movement can complete the flat-ground walking action of the robot.
[0029] The telescopic lengths of the six telescopic linkages are adjusted according to the specific application requirements.
[0030] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A bipedal mobile robot, characterized in that: include: The first top platform, the second top platform, the first foot plate, the second foot plate and the independently controlled driving pair serve as six telescopic branches of the moving pair, the first telescopic branch chain and the second telescopic branch chain are respectively hinged and parallel between one side of the first top platform and one side of the first foot plate, the third telescopic branch chain is connected between the other side of the first foot plate and one side of the second top platform, the fourth telescopic branch chain and the fifth telescopic branch chain are respectively hinged and parallel between the other side of the second top platform and one side of the second foot plate, and the sixth telescopic branch chain is connected between the other side of the second foot plate and the other side of the first top platform; The height and length of the first top platform are greater than the height and length of the second top platform, the first foot plate and the second foot plate are located in the same plane, the initial lengths of the first telescopic branch chain and the second telescopic branch chain are the same and slightly greater than the sixth telescopic branch chain, and greater than the fourth telescopic branch chain and the fifth telescopic branch chain with the same initial length, the third telescopic branch chain is similar in length to the fourth telescopic branch chain, the third telescopic branch chain and the sixth telescopic branch chain are two P branches, and the remaining four telescopic branches are UPU branches, each UPU branch chain has two pairs of parallel rotation pairs, and the six telescopic branches constrain the first top platform and the second top platform to always remain horizontal; In a non-moving state, the moving pairs of the six telescopic branches are released, and the first top platform is extended or shortened by the same length through the first telescopic branch chain, the second telescopic branch chain, and the sixth telescopic branch chain to adjust the distance between the first top platform and the second top platform, and the second top platform is extended or shortened by the same length through the third telescopic branch chain, the fourth telescopic branch chain, and the fifth telescopic branch chain to adjust the distance between the first top platform and the second foot sole plate; In the moving state, the second foot sole touches the ground, the moving pairs of the four UPU branches are locked, the third telescopic branch chain is shortened, and the sixth telescopic branch chain is extended, driving the first top platform and the first foot sole to rise; the moving pairs of the two P branches are locked and the moving pairs of the four UPU branches are released, the first telescopic branch chain, the second telescopic branch chain, the fourth telescopic branch chain and the fifth telescopic branch chain are extended to different lengths respectively, driving the first foot sole and the second top platform to move; the moving pairs of the four UPU branches are locked and the moving pairs of the two P branches are released, the third telescopic branch chain is extended, the sixth telescopic branch chain is shortened, driving the first top platform and the first foot sole to descend; The first foot plate touches the ground, the third telescopic branch chain extends, and the sixth telescopic branch chain shortens, driving the second top platform and the second foot plate to lift; the moving pairs of the two P branches are locked and the moving pairs of the four UPU branches are released, the first telescopic branch chain, the second telescopic branch chain, the fourth telescopic branch chain and the fifth telescopic branch chain are respectively extended and retracted to different lengths, driving the second foot plate and the first top platform to move; the moving pairs of the four UPU branches are locked and the moving pairs of the two P chains are released, the third telescopic branch chain shortens, and the sixth telescopic branch chain extends, driving the second top platform and the second foot plate to descend, completing a gait cycle movement, and repeating the gait cycle movement.
2. The bipedal mobile robot according to claim 1, characterized in that: The front end of the second top platform is provided with a second infrared sensor and an angle sensor, which transmit data to the central controller respectively, and the central controller transmits data to the controllers of the six telescopic branches respectively, and measures the height of obstacles in a non-moving state. The central controller controls the telescopic distances of the third telescopic branch chain, the fourth telescopic branch chain, and the fifth telescopic branch chain through the data fed back by the second infrared sensor and the angle sensor, so as to ensure the obstacle-crossing capability of the first foot plate and the second foot plate; A first infrared sensor is arranged at the bottom center of the first top platform. The first infrared sensor transmits information to the central controller to measure the distance between the first top platform and the second top platform in a non-moving state. The central controller controls the telescopic distances of the first telescopic branch chain, the second branch chain and the sixth branch chain through the data fed back by the first infrared sensor to ensure that the first top platform and the second top platform do not interfere with each other during movement.
3. The bipedal mobile robot according to claim 1, characterized in that: The six telescopic branches are respectively arranged as independent servo electric cylinders, and the two ends of the four UPU branches are respectively connected by Hooke's hinges. The Hooke's hinge includes a rotating pair base, a first rotating pair, a rotating sleeve, a clamping seat and a second rotating pair. The rotating pair base is provided with a connecting hole for connecting with the first top platform or the second top platform or the first foot plate or the second foot plate. One end of the first rotating pair is connected to the rotating pair base through a bearing, and the other end extends into the rotating sleeve from the bottom and is fixed to the rotating sleeve through a locking screw. The two clamping seats are fixed in parallel at the top end of the rotating sleeve. The second rotating pair is connected to the two clamping seats through a bearing. The axis of the first rotating pair is perpendicular to the axis of the second rotating pair. The second rotating pair is fixedly connected to the moving pair of any UPU branch chain.