Low-energy consumption six-legged robot coupled with screw and rope and motion control method

Abstract

A kind of low-energy consumption six-legged robot of screw rod and rope drive coupling and motion control method, it is related to robot design field.The existing six-legged robot uses multiple motor cooperative control, increases control difficulty and the problem of structural complexity.This application includes body, leg mechanism, thigh driving mechanism and shank driving mechanism, leg mechanism is provided with six and left-right symmetrical arrangement in the two sides of body, three leg mechanisms of same side are arranged in order from front to back, thigh driving mechanism is provided with two and left-right symmetrical arrangement in body, and each thigh driving mechanism can drive three leg mechanisms of same side move forward and backward;Each leg mechanism corresponds a shank driving mechanism, and the shank driving mechanism can transmit linear motion generated by thigh driving mechanism to shank, to drive shank to lift or fall.This application is mainly used for executing task in complex environment such as post-disaster search and rescue, field exploration, planet exploration etc..

Description

TECHNICAL FIELD

[0001] The present application relates to the field of robot design, and in particular to a low-energy consumption six-legged robot with coupling of lead screw and rope drive and a motion control method. BACKGROUND

[0002] Six-legged robots have superior motion stability and adaptability in unstructured terrain, and thus exhibit important application potential in complex environments such as post-disaster search and rescue, field exploration, and planetary exploration. Traditional six-legged robots usually adopt a decentralized drive mode, i.e., configuring independent drive motors for each leg or even each joint to achieve precise control of the motion of each leg. Although this design can achieve flexible and diverse gaits, it also leads to problems such as complex overall structure, cumbersome control system, high energy consumption, and high manufacturing cost. In addition, multi-motor cooperative control is difficult, and system reliability is also challenged.

[0003] To reduce the mechanical complexity and control cost of the robot, some designs have been proposed in the prior art to simplify the driving scheme. However, these schemes often only establish coupling within a single leg or between a small number of legs, and the overall coupling degree is limited, the number of motors is not significantly reduced, and often accompanied by problems such as decreased motion flexibility, insufficient gait adjustment ability, etc. Therefore, the existing simplified schemes are difficult to achieve a good balance between maintaining the motion performance of the robot and significantly reducing the driving complexity. SUMMARY

[0004] Therefore, the present application provides a low-energy consumption six-legged robot with coupling of lead screw and rope drive and a motion control method, which can realize a triangular gait mode of the six-legged robot through two drive motors, thereby reducing the mechanical complexity and control cost of the robot.

[0005] The technical scheme adopted by the present application to solve the above technical problems is as follows:

[0006] In a first aspect, the present invention provides a low-energy hexapod robot with screw and cable coupling, comprising a body, leg mechanisms, thigh drive mechanisms, and lower leg drive mechanisms. Six leg mechanisms are arranged symmetrically on both sides of the body, with three leg mechanisms on each side arranged sequentially from front to back. Each leg mechanism includes a thigh and a lower leg that are slidably connected. Two thigh drive mechanisms are arranged symmetrically within the body, and each thigh drive mechanism can drive the three leg mechanisms on the same side to move back and forth. Each leg mechanism corresponds to a lower leg drive mechanism, which includes a winding roller, a steel wire rope, a locking block, a first return spring, a second return spring, and a one-way transmission structure. One end of the steel wire rope is wound around a winding roller. On the roller, the other end splits into two strands. The first strand connects to the lower leg, and the second strand connects to the locking block. The lower leg has a locking groove that engages with the locking block. The first return spring is used to reset the lower leg; the second return spring is used to reset the locking block. The one-way transmission structure can convert the linear motion of the thigh drive mechanism into the rotational motion of the winding roller. When the thigh drive mechanism drives the winding roller to rotate through the transmission of the one-way transmission structure, the winding roller winds up the wire rope, the locking block is pulled out of the locking groove of the lower leg, and the wire rope pulls up the lower leg to raise it. When the one-way transmission structure cuts off the transmission chain, the first return spring drives the lower leg to move down to make it fall, and the second return spring drives the locking block to insert into the locking groove to lock the position of the lower leg.

[0007] Furthermore, the leg mechanism is slidably connected to the machine body. The thigh drive mechanism includes a drive motor, a first lead screw shaft, a second lead screw shaft, a first nut, a second nut, and a gear transmission pair. The first and second lead screw shafts are rotatably mounted on the machine body. The drive motor can drive the first lead screw shaft to rotate. The gear transmission pair connects the first and second lead screw shafts and can drive the second lead screw shaft to rotate in the opposite direction through the transmission cooperation of the gear transmission pair. There are two first nuts, which are respectively screwed to the first lead screw shaft. The second nut is screwed to the second lead screw shaft. The two first nuts can drive the front leg and the rear leg on the same side to move respectively, while the second nut can drive the middle leg on the same side to move.

[0008] Furthermore, the gear transmission pair includes a driving gear and a driven gear. The driving gear is sleeved on the first lead screw shaft, and the driven gear is sleeved on the second lead screw shaft. The driven gear meshes with the driving gear.

[0009] Furthermore, the thigh drive mechanism also includes a guide rail, a sliding sleeve, and a linkage rod. The guide rail is arranged inside the machine body. There are three sliding sleeves that are fitted onto the guide rail. Each sliding sleeve corresponds to a leg mechanism and can drive the corresponding leg mechanism to move. There are three linkage rods that are connected to the three sliding sleeves respectively. The three linkage rods are connected to the second nut and the two first nuts respectively.

[0010] Furthermore, a threading hole is provided along the length of the thigh. The lower leg includes a longitudinal support tube, a transverse support tube, and a leg rod. One end of the longitudinal support tube is fixed to the thigh and communicates with the threading hole in the thigh, while the other end is slidably connected to the leg rod. One end of the transverse support tube is connected to and communicates with the longitudinal support tube, while the other end is connected to the thigh and communicates with the threading hole in the thigh. The first strand of the steel wire rope extends into the longitudinal support tube and is connected to the leg rod. The second strand of the steel wire rope extends into the transverse support tube and is connected to the locking block inside the transverse support tube. The locking block and the transverse support tube are in sliding engagement.

[0011] Furthermore, the unidirectional transmission structure includes a rack, a large gear, a small gear, an incomplete gear, a spur gear, a ratchet, and a pawl. The rack is mounted on the machine body. The large gear can move linearly with the leg mechanism and meshes with the rack, being driven to rotate. The small gear and the incomplete gear are arranged coaxially and mesh with the large gear. The spur gear is fixed coaxially with the ratchet and meshes with the incomplete gear. The winding roller has an annular roller structure. The ratchet is placed inside the winding roller and can rotate freely. One end of the pawl is connected to the winding roller, and the other end is inserted into the ratchet teeth of the ratchet to achieve unidirectional transmission.

[0012] Furthermore, the calf drive mechanism also includes a guide wheel, which is located on one side of the winding roller, and the other end of the wire rope passes around the guide wheel and through the threading hole in the thigh.

[0013] Secondly, the present invention provides a motion control method for a low-energy hexapod robot coupled with a lead screw and cable drive, for controlling the low-energy hexapod robot coupled with a lead screw and cable drive as described in the first aspect, including:

[0014] Gait control while walking in a straight line:

[0015] S101. The target travel speed is the linear feed rate of the leadscrew axis. The required speed n of the drive motor is determined based on the relationship between the linear feed speed of the lead screw shaft, the speed of the drive motor, the lead screw lead, and the reduction ratio; the machine body is then propelled forward based on the speed n of the drive motor.

[0016] Constant radius differential turning gait control:

[0017] S201. Calculate the tangential velocity of the left leg based on the differential steering kinematic model. and the tangential velocity of the right leg ;

[0018] S202. Based on and The corresponding speed control commands are determined based on the relationship between the linear feed speed of the lead screw shaft, the speed of the drive motor, the lead screw lead, and the reduction ratio, so as to realize the constant radius differential turning gait control.

[0019] Furthermore, the differential steering kinematic model is as follows:

[0020]

[0021] in, Angular velocity, The distance between the centers of the robot's left and right legs; The tangential velocity of the left leg. R represents the tangential velocity of the right leg, and R is the turning radius. The velocity is the centerline velocity.

[0022] The beneficial effects of this invention compared to the prior art are as follows:

[0023] 1. The hexapod robot of this invention adopts a triangular gait walking mode, which allows the hexapod robot to be supported by three leg mechanisms located on different sides simultaneously, while the other three leg mechanisms perform stepping movements synchronously. Through the cyclical alternation of two sets of triangular supports, the robot can move forward stably and continuously.

[0024] 2. Each thigh drive mechanism of the present invention uses a single motor and two lead screw and nut pairs for continuous transmission. At the same time, under the coupling of the rope drive structure and the unidirectional transmission structure, the coordinated movement of the three legs on the same side is realized. The overall structure is compact and simple to control, which can effectively ensure the symmetry and stability of the gait and realize the robot's periodic gait walking.

[0025] 3. The lower leg drive mechanism of this invention adopts a rope drive method, and in conjunction with a one-way transmission structure, intermittently transmits the linear motion generated by the thigh drive mechanism to the lower leg, driving the lower leg lever to achieve up-and-down reciprocating motion, thereby completing the lifting and lowering actions of the leg. The incomplete gear design in the one-way transmission structure ensures reliable power transmission before the front and rear legs reach the designated positions, controlling the lower leg to lift. At the moment of reaching the position, the transmission chain is automatically cut off, allowing the lower leg to quickly extend and support the ground. This ensures that the one-way transmission structure can orderly control the lifting and lowering of the lower leg, achieving precise motion control, and also ensuring that the winding roller can rotate freely without interference under the load of the lower leg. The ratchet and pawl design prevents the linear motion of the thigh drive mechanism from being transmitted to the lower leg, ensuring that the lower leg in contact with the ground remains in a pushing-off state, thus enabling the robot to move forward. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are provided to give a further understanding of the invention.

[0027] Figure 1 This is a schematic diagram of the structure of a low-energy six-legged robot with lead screw and cable coupling according to the present invention.

[0028] Figure 2 This is a schematic diagram of the internal structure of a low-energy six-legged robot with lead screw and cable coupling according to the present invention (with the front baffle, top cover and bottom plate of the robot body removed).

[0029] Figure 3 This is an assembly drawing of the left leg mechanism, the thigh drive mechanism, and the three lower leg drive mechanisms.

[0030] Figure 4 for Figure 3 Enlarged view of a portion of point A in the middle.

[0031] Figure 5 This is a front cross-sectional view of the present invention.

[0032] Figure 6 for Figure 5 A magnified view of a section at point B in the middle.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Body; 11. Slide rail; 2. Leg mechanism; 21. Thigh; 211. Threading hole; 22. Lower leg; 221. Longitudinal support tube; 222. Lateral support tube; 223. Leg rod; 23. Foot; 3. Thigh drive mechanism; 31. Drive motor; 32. First lead screw shaft; 33. Second lead screw shaft; 34. First nut; 35. Second nut; 36. Driving wheel; 37. Driven wheel; 38. Guide rail; 39. Sliding sleeve; 310. Linkage 4. Leg drive mechanism; 41. Winding roller; 42. Guide wheel; 43. Wire rope; 44. Locking block; 45. First return spring; 46. Second return spring; 47. First support rod; 48. Second support rod; 49. One-way transmission structure; 491. First support shaft; 492. Second support shaft; 493. Spur rack; 494. Large gear; 495. Small gear; 496. Incomplete gear; 497. Spur gear; 498. Ratchet. Detailed Implementation

[0035] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] See Figure 1 , Figure 2 and Figure 3This embodiment of a low-energy hexapod robot with screw and cable coupling includes a body 1, leg mechanisms 2, thigh drive mechanisms 3, and lower leg drive mechanisms 4. Six leg mechanisms 2 are symmetrically arranged on both sides of the body 1. The three leg mechanisms 2 on the same side are arranged sequentially from front to back. Specifically, the three leg mechanisms 2 on the left side of the body 1 are designated as the left front leg, left middle leg, and left hind leg, and the three leg mechanisms 2 on the right side of the body 1 are designated as the right front leg, right middle leg, and right hind leg, respectively. Two thigh drive mechanisms 3 are symmetrically arranged within the body 1. Each thigh drive mechanism 3 can drive the three leg mechanisms 2 on the same side to move back and forth. The front and hind legs on the same side and the middle leg on the opposite side form a group of coordinated motion units, i.e., there are two groups of coordinated motion units. The three leg mechanisms 2 in each group of coordinated motion units move in the same direction, while the two groups of coordinated motion units move in opposite directions. Specifically, the left front leg, left hind leg, and right middle leg form one group, and the right front leg, right hind leg, and left middle leg form another group. The left thigh drive mechanism 3 drives the left front leg and left hind leg to move forward / backward and drives the left middle leg to move backward / forward. The right thigh drive mechanism 3 drives the right front leg and right hind leg to move backward / forward and drives the right middle leg to move forward / backward, thus achieving three-point support. Each leg mechanism 2 corresponds to a lower leg drive mechanism 4, and the lower leg 22 can be raised and lowered by the corresponding lower leg drive mechanism 4.

[0037] In one set of coordinated motion units, three leg mechanisms 2 are driven forward by the thigh drive mechanism 3, while the lower legs 22 of these three leg mechanisms 2 are driven upward by the corresponding lower leg drive mechanism 4. Meanwhile, in another set of coordinated motion units, three leg mechanisms 2 are driven backward by the thigh drive mechanism 3, while the lower legs 22 of these three leg mechanisms 2 support the ground, and the body 1 moves forward under the reaction force of the ground. The two sets of coordinated motion units alternately perform stepping movements in opposite directions, forming a triangular gait walking pattern. This design ensures that the hexapod robot's body 1 is always supported simultaneously by three leg mechanisms 2 located on different sides, while the other three leg mechanisms 2 perform stepping movements synchronously. Through the cyclical alternation of the two sets of triangular supports, the robot achieves stable and continuous forward movement.

[0038] See Figure 1 and Figure 2 In this embodiment, the body 1 has a rectangular structure. Slides 11 are respectively provided on the left and right side plates of the body 1. Each leg mechanism 2 includes a thigh 21, a calf 22, and a foot 23 connected sequentially. One end of the thigh 21 passes through the slide 11 of the body 1 and connects to the thigh drive mechanism 3. The other end extends horizontally away from the body 1 and connects to one end of the calf 22. The other end of the calf 22 extends vertically downward and connects to the foot 23. The calf 22 is a retractable structure and can be driven to extend and retract by the calf drive mechanism 4, realizing the raising and lowering of the calf 22.

[0039] See Figure 2 and Figure 3 The thigh drive mechanism 3 in this embodiment includes a drive motor 31, a first lead screw shaft 32, a second lead screw shaft 33, two first nuts 34, a second nut 35, a drive wheel 36, a driven wheel 37, a guide rail 38, three sliding sleeves 39, and three linkage rods 310. The drive motor 31 is fixed to the side plate of the machine body 1 via a motor mount and is used to provide power output. The first lead screw shaft 32 and the second lead screw shaft 33 are arranged in parallel and rotatably mounted on the side plate of the machine body 1. One end of the first lead screw shaft 32 is connected to the output shaft of the drive motor 31 and can rotate under the drive of the drive motor 31. The drive wheel 36 and the driven wheel 37 form a gear transmission pair to transmit the rotational motion of the first lead screw shaft 32 to the second lead screw shaft 33. Specifically, the drive wheel 36 is sleeved on the first lead screw shaft 32, and the driven wheel 37 is sleeved on the second lead screw shaft 33. The two are linked by meshing, so that the second lead screw shaft 33 rotates synchronously in the opposite direction with the first lead screw shaft 32. Guide rails 38 are arranged inside the body 1. Two guide rails 38 in the left and right thigh drive mechanisms 3 are fixed to the front and rear baffles of the body 1 by two crossbeams arranged front and rear. Three sliding sleeves 39 are sequentially fitted on the guide rails 38 and can slide back and forth along the length of the guide rails 38. Each sliding sleeve 39 is connected to the three thighs 21 (front leg, middle leg, and rear leg) on ​​the same side to realize power transmission. Three linkage rods 310 correspond one-to-one with the three sliding sleeves 39. One end of each linkage rod 310 is fixed to the corresponding sliding sleeve 39, and the other end extends vertically downward to transmit power. Two first nuts 34 are screwed onto the first lead screw shaft 32 and are each connected to two of the linkage rods 310 through a connecting block; the second nut 35 is screwed onto the second lead screw shaft 33 and is also connected to the third linkage rod 310 through a connecting block. The two first nuts 34 drive the front leg and rear leg on the same side respectively, while the second nut 35 is located between them and drives the middle leg on the same side.

[0040] Since the hexapod robot in this embodiment adopts a triangular gait walking mode, the gait of the left and right leg mechanisms 2 is opposite in one gait cycle. This embodiment uses the example of the left front leg, left hind leg, and right middle leg stepping forward while the right front leg, right hind leg, and left middle leg support and push off the ground backward to explain the driving process of the left and right thigh drive mechanisms 3 in detail:

[0041] The drive motor 31 in the left thigh drive mechanism 3 starts, driving the first lead screw shaft 32 to rotate forward. Under the constraint of the guide rail 38 and the corresponding sliding sleeve 39, the two first nuts 34 move forward along the axial direction of the first lead screw shaft 32. The two first nuts 34 drive the left front leg and the left rear leg to move forward synchronously through the transmission cooperation of the linkage rod 310 and the sliding sleeve 39, respectively, to complete the stepping action. At the same time, the driving wheel 36 fixed to the first lead screw shaft 32 rotates forward with it, and drives the second lead screw shaft 33 to rotate in the opposite direction through the driven wheel 37. Under the guidance of the guide rail 38 and the sliding sleeve 39, the second nut 35 on the second lead screw shaft 33 moves backward along the axial direction, thereby driving the left middle leg to move backward relative to the body 1. At this time, the left middle leg forms a support and push-off posture, realizing the forward movement of the body 1. The right thigh drive mechanism 3 moves in the opposite direction to the left. Its drive motor 31 drives the first lead screw shaft 32 to rotate in the opposite direction, causing the two first nuts 34 to move axially backward. This, in turn, drives the right front leg and right hind leg to move backward synchronously, providing support and pushing off the ground. Simultaneously, under the transmission cooperation of the drive wheel 36 and the driven wheel 37, the second lead screw shaft 33 rotates forward, causing the second nut 35 to move axially forward, thereby driving the right middle leg to swing forward and participate in the stepping motion. After the first gait cycle is completed, the left thigh drive mechanism 3 begins to drive in the opposite direction, while the right thigh drive mechanism 3 drives forward, enabling the robot to enter the next gait cycle. This cycle repeats, achieving forward movement for the hexapod robot.

[0042] In this embodiment, each thigh drive mechanism 3 uses a single motor and two lead screw and nut pairs to achieve coordinated movement of the three legs on the same side. The overall structure is compact and easy to control, which can effectively ensure the symmetry and stability of the gait and realize the robot's periodic gait walking.

[0043] See Figure 3 and Figure 5 In this embodiment, a threading hole 211 is provided inside the thigh 21 along its length direction. The lower leg 22 includes a longitudinal support tube 221, a transverse support tube 222, and a leg rod 223. One end of the longitudinal support tube 221 is fixed to the extension end of the thigh 21 and communicates with the threading hole 211 of the thigh 21, while the other end is slidably connected to the leg rod 223. One end of the transverse support tube 222 is connected to and communicates with the longitudinal support tube 221, while the other end is connected to the thigh 21 and communicates with the threading hole 211 inside the thigh 21.

[0044] In this embodiment, the lower leg drive mechanism 4 adopts a rope drive mechanism, which can transmit the linear motion generated by the thigh drive mechanism 3 to the lower leg 22, thereby driving the lower leg 22 leg rod 223 to achieve up-and-down reciprocating motion, thus completing the lifting and lowering action of the leg.

[0045] Specifically, such as Figure 3 and Figure 4As shown, each leg drive mechanism 4 in this embodiment includes a winding roller 41, a guide wheel 42, a wire rope 43, a locking block 44, a first return spring 45, a second return spring 46, and a one-way transmission structure 49. The winding roller 41 is rotatably mounted on one side of the linkage rod 310 via a first support rod 47. The guide wheel 42 is disposed on one side of the winding roller 41 via a second support rod 48. One end of the wire rope 43 is wound around the winding roller 41, and the other end passes around the guide wheel 42 and passes through the threading hole 211 of the thigh 21. The other end of the wire rope 43 is divided into two strands. The first strand extends into the longitudinal support tube 221 and connects to the leg rod 223. The second strand extends into the transverse support tube 222 and connects to the locking block 44 inside the transverse support tube 222. The locking block 44 and the transverse support tube 222 are in sliding engagement. The locking block 44 is wedge-shaped, and a locking groove (not shown in the figure) that engages with the locking block 44 is provided near the upper end of the leg rod 223. The first return spring 45 is located inside the longitudinal support tube 221 and sleeved on the first strand of the wire rope 43. This first return spring 45 is used for the return of the leg bar 223. The second return spring 46 is located inside the transverse support tube 222 and sleeved on the second strand of the wire rope 43. The one-way transmission structure 49 connects the linkage rod 310 in the thigh drive mechanism 3 with the winding roller 41, which can convert the linear motion of the linkage rod 310 into the rotational motion of the winding roller 41, thereby realizing the winding or unwinding of the wire rope 43.

[0046] During the movement of the thigh drive mechanism 3 driving the leg mechanism 2, as the left front leg, left rear leg, and right middle leg step forward, the corresponding lower leg drive mechanism 4 generates a driving action. That is, the one-way transmission structure 49 converts the linear motion of the linkage rod 310 into the rotational motion of the winding roller 41. The winding roller 41 winds up the wire rope 43, and the second strand of the wire rope 43 overcomes the elastic force of the second return spring 46 to pull the locking block 44 out of the locking groove of the leg rod 223. At the same time, the first strand of the wire rope 43 overcomes the elastic force of the first return spring 45 to pull the leg rod 223 upward, thereby realizing the lifting of the lower leg 22. The unidirectional transmission structure 49 has the characteristics of unidirectional and intermittent transmission. When the left front leg, left rear leg, and right middle leg move to the predetermined position, the unidirectional transmission structure 49 no longer converts the linear motion of the linkage rod 310 into the rotational motion of the winding roller 41. The winding roller 41 is in a free rotation state. Under the rebound force of the first return spring 45 and its own gravity, the leg rod 223 quickly extends out of the longitudinal support tube 221, and the foot supports the ground. At the same time, the locking block 44 is inserted into the locking groove of the leg rod 223 under the rebound force of the second return spring 46, realizing the locking of the position of the lower leg 22 and ensuring the stability of the lower leg 22 supporting the ground. During this process, both the leg rod 223 and the locking block 44 will pull the wire rope 43, the winding roller 41 will rotate in the opposite direction, and the wire rope 43 will be released.

[0047] When the left front leg, left hind leg, and right middle leg step forward, the right front leg, right hind leg, and left middle leg must maintain a supporting position on the ground. Therefore, the lower leg drive mechanism 4 corresponding to these three legs should not perform any driving action. In this embodiment, by utilizing the unidirectional transmission characteristic of the unidirectional transmission structure 49, the linear motion of the linkage rod 310 cannot be transmitted to the winding roller 41, thereby ensuring that the right front leg, right hind leg, and left middle leg can continuously and stably support the ground.

[0048] To achieve the unidirectional and intermittent transmission characteristics of the unidirectional transmission structure 49, this embodiment utilizes the cooperative operation of a ratchet mechanism and a transmission gear pair with an incomplete gear 496. For details, see... Figure 4 The unidirectional transmission structure 49 of this embodiment includes a first support shaft 491, a second support shaft 492, a rack 493, a large gear 494, a small gear 495, an incomplete gear 496, a spur gear 497, a ratchet 498, and a pawl (not shown in the figure). The first support shaft 491, the second support shaft 492, the rack 493, the large gear 494, the small gear 495, the incomplete gear 496, and the spur gear 497 constitute a transmission gear pair, and the ratchet 498 and the pawl constitute a ratchet mechanism. The rack 493 is mounted on the side plate of the body 1, and the spur gear 497 in the three unidirectional transmission structures 49 on the same side can be integrally manufactured. A large gear 494 is rotatably mounted on a linkage rod 310 and meshes with a spur rack 493. A first support shaft 491 is rotatably mounted on one side of the linkage rod 310 via a third support rod. A small gear 495 and an incomplete gear 496 are sequentially fitted onto the first support shaft 491 from top to bottom, with the small gear 495 meshing with the large gear 494. The winding roller 41 has an annular roller structure. A ratchet 498 is coaxially disposed inside the winding roller 41 and rotatably mounted on the first support rod 47 via a second support shaft 492. One end of the ratchet pawl is connected to the winding roller 41, and the other end is inserted into the ratchet teeth of the ratchet 498. A spur gear 497 is fitted onto the second support shaft 492 and meshes with the incomplete gear 496.

[0049] Since the transmission process of the unidirectional transmission structure 49 of the front leg and the rear leg is the same, the transmission process of the middle leg is different from that of the front leg and the rear leg. Therefore, this embodiment takes the left front leg and the left rear leg stepping forward and the left middle leg supporting the ground as an example to illustrate the two transmission processes.

[0050] As the left front leg and left hind leg step forward, the linkage rods 310 corresponding to these two legs move forward relative to the machine body 1. The large gear 494 mounted on these two linkage rods 310 rotates counterclockwise under the drive of the rack 493, thereby driving the small gear 495 and the incomplete gear 496 to rotate clockwise. The incomplete gear 496 drives the spur gear 497 and the ratchet 498 to rotate counterclockwise. The ratchet 498 drives the winding roller 41 to rotate counterclockwise via its pawl, and the winding roller 41 winds up the wire rope 43. When the left front leg and left hind leg move synchronously to the predetermined position, the missing tooth portion of the incomplete gear 496 rotates precisely to the position corresponding to the spur gear 497. At this point, the linear motion of the linkage rods 310 can no longer be transmitted to the spur gear 497, and the winding roller 41 stops winding up the wire rope 43. Meanwhile, under the combined traction of the leg 223 and the locking block 44, the wire rope 43 drives the winding roller 41 to rotate clockwise; the winding roller 41 drives the ratchet 498 through the pawl, which in turn drives the spur gear 497 to rotate clockwise as well. Since the missing tooth section of the incomplete gear 496 is directly opposite the spur gear 497, the spur gear 497 is actually in an idle state and does not obstruct the clockwise rotation of the winding roller 41.

[0051] During the process of the left middle leg supporting the ground, the linkage rod 310 corresponding to this leg moves backward relative to the body 1. The large gear 494 mounted on the linkage rod 310 rotates clockwise, thereby driving the small gear 495 and the incomplete gear 496 to rotate counterclockwise. The incomplete gear 496 drives the spur gear 497 and the ratchet 498 to rotate clockwise. At this time, the ratchet 498 rotates idly and will not drive the winding roller 41 to rotate through the pawl. Therefore, the length of the wire rope 43 wound on the winding roller 41 remains unchanged and will not generate driving force on the lower leg 22 of the left middle leg.

[0052] Clearly, the design of the incomplete gear 496 in this embodiment can reliably transmit power before the left front leg and left rear leg reach the designated position, controlling the lower leg 22 to lift. At the moment of reaching the position, the transmission chain is automatically cut off, allowing the lower leg 22 to quickly extend and support the ground. This ensures that the unidirectional transmission structure 49 can orderly control the lifting and lowering of the lower leg 22, achieving precise motion control. It also ensures that the winding roller 41 can rotate freely without interference under the load of the lower leg 22. The design of the ratchet 498 and pawl prevents the linear motion of the thigh drive mechanism 3 from being transmitted to the lower leg 22, ensuring that the lower leg 22 in contact with the ground remains in a pushing-off state, thus enabling the robot to move forward.

[0053] How a six-legged robot works:

[0054] Taking the example of the left front leg, left hind leg, and right middle leg stepping forward while the right front leg, right hind leg, and left middle leg support and push off the ground backward, the entire gait process of the hexapod robot is explained in detail.

[0055] Forward movement: The drive motor 31 in the left thigh drive mechanism 3 starts, driving the first lead screw shaft 32 to rotate forward. Under the constraint of the guide rail 38 and the corresponding sliding sleeve 39, the two first nuts 34 move forward along the axial direction of the first lead screw shaft 32. The two first nuts 34 drive the left front leg and the left rear leg to move forward synchronously through the transmission cooperation of the linkage rod 310 and the sliding sleeve 39. Since the linkage rod 310 corresponding to the two legs moves forward relative to the machine body 1, the large gear 494 mounted on the two linkage rods 310 rotates counterclockwise under the drive of the rack 493, thereby driving the small gear 495 and the incomplete gear 496 to rotate clockwise. The incomplete gear 496 drives the spur gear 497 and the ratchet 498 to rotate counterclockwise. The ratchet 498 drives the winding roller 41 to rotate counterclockwise through the pawl, and the winding roller 41 winds up the wire rope 43. The second strand of wire rope 43 overcomes the elastic force of the second return spring 46 and pulls the locking block 44 out of the locking groove of the leg bar 223. At the same time, the first strand of wire rope 43 overcomes the elastic force of the first return spring 45 and pulls the leg bar 223 upward, thereby raising the lower leg 22. When the left front leg and the left rear leg move synchronously to the predetermined position, the missing tooth part of the incomplete gear 496 rotates exactly to the position corresponding to the spur gear 497. At this time, the linear motion of the linkage rod 310 can no longer be transmitted to the spur gear 497, and the winding roller 41 stops winding the wire rope 43. The winding roller 41 is in a free rotation state, and the leg bar 223 quickly extends out of the longitudinal support tube 221 under the rebound force of the first return spring 45 and its own gravity, with the foot supporting the ground. At the same time, the locking block 44 is inserted into the locking groove of the leg bar 223 under the rebound force of the second return spring 46, locking the position of the lower leg 22 and ensuring the stability of the lower leg 22 supporting the ground.

[0056] Simultaneously, the drive wheel 36 fixed to the first lead screw shaft 32 rotates in the forward direction and drives the second lead screw shaft 33 to rotate in the reverse direction through the driven wheel 37. The second nut 35 on the second lead screw shaft 33 moves backward along the axial direction under the guidance of the guide rail 38 and the sliding sleeve 39, thereby driving the left middle leg to move backward relative to the body 1. The linkage rod 310 corresponding to this leg moves backward relative to the body 1. The large gear 494 assembled on the linkage rod 310 rotates clockwise, thereby driving the small gear 495 and the incomplete gear 496 to rotate counterclockwise. The incomplete gear 496 drives the spur gear 497 and the ratchet 498 to rotate clockwise. At this time, the ratchet 498 rotates idly and will not drive the winding roller 41 to rotate through the pawl. Therefore, the length of the wire rope 43 wound on the winding roller 41 remains unchanged and will not generate driving force on the lower leg 22 of the left middle leg. The left middle leg is always in the state of pushing off the ground, realizing the forward movement of the robot.

[0057] The right thigh drive mechanism 3 moves in the opposite direction to the left. Its drive motor 31 drives the first lead screw shaft 32 to rotate in the opposite direction, causing the two first nuts 34 to move axially backward. This, in turn, drives the right front leg and right hind leg to move backward synchronously, providing support and pushing off the ground. Simultaneously, under the transmission cooperation of the drive wheel 36 and the driven wheel 37, the second lead screw shaft 33 rotates forward, causing the second nut 35 to move axially forward, thereby driving the right middle leg to swing forward and participate in the stepping motion. After the first gait cycle is completed, the left thigh drive mechanism 3 begins to drive in the opposite direction, while the right thigh drive mechanism 3 drives forward, enabling the robot to enter the next gait cycle. This cycle repeats, achieving forward movement for the hexapod robot.

[0058] Turning Process: The hexapod robot's turning motion is achieved by controlling the speed difference between the left and right drive motors 31. Since the left drive motor 31 controls the reciprocating stepping frequency of the three left legs, and the right drive motor 31 controls the reciprocating stepping frequency of the three right legs, when there is a difference in speed between the two drive motors 31, the stepping speeds of the two leg mechanisms 2 will differ, resulting in differential turning of the hexapod robot. When the speed of the left drive motor 31 is higher than that of the right drive motor 31, the robot turns right; conversely, it turns left.

[0059] Example 2:

[0060] This embodiment also proposes a low-energy hexapod robot motion control method coupled with a lead screw and cable drive, including:

[0061] To perform quantitative calculations, the parameters of the hexapod robot prototype in this embodiment are set as follows before control is implemented:

[0062] The robot's total mass m = 10 kg; the center-to-center distance between the left and right legs W = 400 mm (0.4 m); the lead screw pitch Ph = 10 mm (0.01 m); the transmission mechanism reduction ratio i = 1:1 (the motor output shaft is directly connected to the lead screw shaft); the effective stroke of a single leg S = 200 mm;

[0063] Controlling a hexapod robot with predefined prototype parameters includes:

[0064] Gait control while walking in a straight line:

[0065] The target operating condition in this embodiment is: the robot moves at v target It travels forward in a straight line at a speed of 0.2 m / s.

[0066] S101. Calculate the motor speed:

[0067] In linear walking mode, the left and right motors must rotate synchronously at the same speed. The linear feed speed of the lead screw axis is the robot's theoretical walking speed, i.e.:

[0068]

[0069] In the formula: Walking speed (m / s); Motor speed (RPM); is the lead of the lead screw (m); i is the reduction ratio.

[0070] Based on the robot's target travel speed (i.e., substituted into v) target =0.2m / s), calculate the required speed n of the drive motor:

[0071]

[0072] Sending control commands: The controller simultaneously sends a forward rotation command of 1200 RPM to the left drive motor (ML) and the right drive motor (MR). At this time, because the adjacent lead screw shafts are meshed in opposite directions through gears, a set of three legs on each side supports the ground and moves backward, propelling the machine body forward at a speed of 0.2 m / s.

[0073] Constant radius differential turning gait control:

[0074] The target working condition in this embodiment is: the robot needs to make a right turn with a turning radius R = 1.0m (with the robot's geometric center as the origin), and the center linear velocity... Maintain a speed of 0.2 m / s. It should be noted that in this implementation, controlling the robot to turn right and turning left are essentially the same; only the calculations for the left and right legs need to be interchanged.

[0075] S201. Based on the differential steering kinematic model, calculate the tangential velocity of the left leg and the tangential velocity of the right leg:

[0076] This embodiment uses dual motors to independently drive the left and right sides, conforming to the differential steering kinematic model. The tangential velocity of the left leg ( ): Outer wheel, speed needs to be increased; Right leg tangential speed ( ): Inner wheel, speed needs to be reduced.

[0077] The kinematic model for differential steering is as follows:

[0078]

[0079] in, Angular velocity, The distance between the center of the left and right legs of the robot / wheel track.

[0080] In this embodiment, the parameters are substituted. Then we have:

[0081] Angular velocity:

[0082]

[0083] Left side speed:

[0084]

[0085] Right side speed:

[0086]

[0087] S202. Calculate and output speed control commands:

[0088] The motor speed is calculated using n = (v × 60) / Ph, where,

[0089] Left motor speed :

[0090]

[0091] Right motor speed :

[0092]

[0093] The controller outputs a command to accelerate the left motor to 1440 RPM, while simultaneously decelerating the right motor to 960 RPM.

[0094] Under this control, the stepping frequency of the left leg is approximately 1.5 times that of the right leg (1440 / 960). Due to the high-coupling design of this mechanism, the change in frequency directly translates into a change in the travel distance, thereby generating a torque that drives the robot to achieve a smooth right turn.

[0095] The hexapod robot in this embodiment achieves its functionality solely by adjusting the speed ratio (n) of its two drive motors. L :n R This allows for precise mapping to the robot's turning radius and travel speed.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions created by the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions created by the present invention without departing from the essence and scope of the technical solutions created by the present invention.

Claims

1. A low-energy consumption hexapod robot coupled with a wire screw and a rope, characterized in that, The application relates to a leg mechanism and a thigh driving mechanism, and the leg mechanism is slidably connected with the body, and the thigh driving mechanism comprises a driving motor, a first screw shaft, a second screw shaft, a first nut, a second nut and a gear transmission pair, the first screw shaft and the second screw shaft are rotatably installed on the body, the driving motor can drive the first screw shaft to rotate, the gear transmission pair is connected between the first screw shaft and the second screw shaft, and the second screw shaft can be driven to rotate reversely through the transmission cooperation of the gear transmission pair; the first nut is provided with two first nuts which are respectively screwed on the first screw shaft, and the second nut is screwed on the second screw shaft, so that the two first nuts can drive the front leg and the rear leg on the same side to move respectively, and the second nut can drive the middle leg on the same side to move. The thigh is provided with a threading hole along the length direction, the calf comprises a longitudinal supporting pipe, a transverse supporting pipe and a leg rod, one end of the longitudinal supporting pipe is fixedly connected to the thigh and communicates with the threading hole in the thigh, the other end of the longitudinal supporting pipe is slidably connected with the leg rod, one end of the transverse supporting pipe is connected with the longitudinal supporting pipe and communicates with the longitudinal supporting pipe, and the other end of the transverse supporting pipe is connected with the thigh and communicates with the threading hole in the thigh; the first strand of the steel wire rope extends into the longitudinal supporting pipe and is connected with the leg rod, the second strand of the steel wire rope extends into the transverse supporting pipe and is connected with the locking block in the transverse supporting pipe, and the locking block is slidably connected with the transverse supporting pipe. The one-way transmission structure comprises a straight rack, a large gear, a small gear, an incomplete gear, a straight gear, a ratchet wheel and a pawl, the straight rack is installed on the body, the large gear can move linearly with the leg mechanism, is in mesh connection with the straight rack and is driven to rotate, the small gear and the incomplete gear are coaxially arranged and are in mesh connection with the large gear, the straight gear and the ratchet wheel are coaxially fixed and are in mesh connection with the incomplete gear, the winding roller is in the ring roller structure, the ratchet wheel is arranged in the winding roller and can rotate freely, one end of the pawl is connected to the winding roller, and the other end of the pawl is inserted into the ratchet tooth of the ratchet wheel, so that the one-way transmission is realized. ​ 2. The low-energy consumption six-legged robot coupled with a wire rod and a rope according to claim 1, wherein, The gear transmission pair comprises a driving gear and a driven gear, the driving gear is sleeved on the first screw shaft, the driven gear is sleeved on the second screw shaft, and the driven gear is engaged with the driving gear.

3. The low-power consumption six-legged robot coupled by wire drive and wire rope according to claim 1, characterized in that, The thigh driving mechanism further comprises a guide rail, a sliding sleeve and a linkage rod, the guide rail is arranged in the fuselage, the sliding sleeve is provided with three sleeves and is sleeved on the guide rail, each sliding sleeve corresponds to a leg mechanism and can drive the corresponding leg mechanism to move, and the linkage rod is provided with three and is connected with the three sliding sleeves respectively.

4. The low-power consumption six-legged robot coupled by wire drive and rope drive according to claim 1, characterized in that, The small leg driving mechanism further comprises a guide wheel, the guide wheel is located on one side of the winding roller, and the other end of the steel wire rope passes through the guide wheel and then penetrates into the threading hole of the thigh.

5. A motion control method of a low-energy consumption hexapod robot coupled with a wire drive and a rope drive, characterized in that, A low-energy consumption hexapod robot coupled by a screw rod and a rope according to any one of claims 1 to 4 is controlled, comprising: Linear walking gait control: S101. The linear feed speed of the screw rod shaft is taken as the target walking speed, the required rotation speed n of the driving motor is determined according to the relationship between the linear feed speed of the screw rod shaft, the rotation speed of the driving motor, the lead of the screw rod and the speed reduction ratio, and the driving motor is driven to move the fuselage forward based on the rotation speed n; Constant radius differential steering turning gait control: S201. Calculate the left leg tangential velocity based on the differential steering kinematics model and the right leg tangential velocity ; S202. Based on and , the corresponding speed control instructions are determined according to the relationship between the linear feed speed of the screw shaft and the driving motor speed, the screw lead, and the speed reduction ratio, respectively, to realize the differential turning gait control with a fixed radius.

6. The motion control method of the low-energy consumption six-legged robot coupled by wire drive and lead screw according to claim 5, wherein, The differential steering kinematic model is as follows: The differential steering kinematic model is as follows: wherein, is the angular velocity, is the center distance between the left and right legs of the robot; is the tangential velocity of the left leg, is the tangential velocity of the right leg, R is the turning radius, is the centerline velocity.

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