A bidirectional deformable and isotropic spoked wheel mechanism

Abstract

This invention discloses a bidirectional deformable and isotropic spoked wheel mechanism, belonging to the field of robotics. The spoked wheel mechanism includes a drive shaft rotatably mounted on a vehicle body. An inner hub is coaxially fixed to the end of the drive shaft. A tripod is coaxially fixed to one side of the inner hub. Three cylinders evenly distributed circumferentially are arranged on the tripod, and a driven gear is rotatably connected to each cylinder. A driving gear is rotatably connected to the center of the tripod, and all three driven gears mesh with the driving gear. A deformable wheel is coaxially arranged on one side of the inner hub. The deformable wheel includes three arc segments. Two connecting rods are installed between each arc segment and the driven gear. One end of the connecting rod is hinged to the arc segment, and the other end is rotatably connected to the driven gear. A fixed rod is rotatably connected to the middle position of each arc segment. An outer hub is coaxially arranged on one side of the deformable wheel. The fixed rod is fixedly connected to the outer hub, and a motor is fixed to the outer hub to drive the driving gear to rotate.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology, specifically relating to a bidirectional deformable and isotropic spoked wheel mechanism. Background Technology

[0002] In robotics, the most common locomotion modes are wheeled and legged. Each has its own characteristics. Wheeled robots offer advantages such as low energy consumption, simple mechanical structure, easy motion control, and good maneuverability on open, flat terrain. However, wheeled robots struggle to traverse uneven terrain, such as potholes and steps. Compared to wheeled robots, legged robots excel at handling various environments, but they are slower, more complex in structure, and require more sophisticated control. Employing only one form of locomotion cannot simultaneously achieve both high efficiency and terrain adaptability. Therefore, various robots combining different locomotion modes have emerged in land-based mobile robotics. Wheel-legged hybrid robots not only achieve high efficiency and strong terrain adaptability but also allow for algorithmic improvements to enhance stability in diverse environments. Thus, deformable spoked wheel mechanisms hold immense potential in complex environment applications and have become a major research focus in the field of land-based mobile robotics.

[0003] For example, the WheeleLeR robot developed by Case Western Reserve University in the United States can passively switch between wheels and legs; the LDR robot developed by the State Key Laboratory of Mechanical Transmission at Chongqing University can switch between wheels and legs through an active mechanism. However, both robots can only switch in one direction, resulting in different contact patterns between the legs and the ground during forward and reverse movements. Xu Qiwei et al. from Shanghai Jiao Tong University proposed a deformable wheeled robot with three motion modes. The deformable wheels can actively switch between circular wheel, CW (circular wheel) leg wheel mode, and CCW (convertible wheel) leg wheel mode, but the leg mode differs when switching between forward and reverse directions.

[0004] In summary, existing deformable spoked wheel mechanisms have inconsistent motion mechanisms in the forward and backward directions after deformation. For the forward and backward movements, it is necessary to analyze the motion characteristics and design independent control algorithms, which increases the workload of developers. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a bidirectional deformable and isotropic spoked wheel mechanism, thus solving the problems in the prior art.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A bidirectional deformable and isotropic spoked wheel mechanism is installed on one side of a vehicle body. It includes a drive shaft rotatably mounted on the vehicle body, an inner hub coaxially fixed to the end of the drive shaft, a triangular frame fixed to one side of the inner hub, the central axis of the triangular frame coinciding with the axis of the drive shaft, three circumferentially evenly distributed cylinders on the triangular frame, a driven gear rotatably connected to each cylinder, and a driving gear rotatably connected to the center of the triangular frame. All three driven gears mesh with the driving gear.

[0008] A deformable wheel is coaxially mounted on one side of the inner hub. The deformable wheel consists of three arc segments. Each arc segment is connected to two connecting rods with the driven gear. One end of the connecting rod is hinged to the arc segment, and the other end is rotatably connected to the driven gear. A fixed rod is rotatably connected to the middle position of each arc segment. An outer hub is coaxially mounted on one side of the deformable wheel. The fixed rod is fixedly connected to the outer hub. A motor is fixed on the outer hub to drive the drive gear to rotate.

[0009] Furthermore, a motor is installed on the vehicle body, and the drive shaft is rotatably connected to the vehicle body, driving the drive shaft to rotate.

[0010] Furthermore, bearings are installed on the vehicle body, and the drive shaft is rotatably connected to the vehicle body through the bearings.

[0011] Furthermore, each driven gear is provided with a retaining plate, which can limit the rotation position of the connecting rod.

[0012] Furthermore, a motor transmission rod is coaxially fixed on the drive shaft of motor two, and the motor transmission rod is fixed to the drive gear.

[0013] Furthermore, the transmission ratio between the driving gear and the driven gear is 5:6.

[0014] Furthermore, an electric slip ring is fixed on the vehicle body, and the drive shaft passes through the electric slip ring and rotates synchronously with the rotor of the electric slip ring.

[0015] A robot includes a vehicle body and the aforementioned spoked wheel mechanism.

[0016] The beneficial effects of this invention are:

[0017] 1. The deformable spoked wheel mechanism of the present invention has a wheel form and a leg form. On flat ground, the wheel form is used to improve the mobility of the vehicle, and on rugged ground, the leg form is used to overcome various obstacles. The flexible switching between wheel and leg forms improves the robot's terrain adaptability.

[0018] 2. The deformable spoke wheel mechanism of the present invention has the characteristics of bidirectional deformation and isotropy. It can achieve control in two directions by only performing motion analysis and algorithm design in one direction. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of the deformable spoke wheel mechanism of the present invention;

[0021] Figure 2 This is an exploded view of the overall structure of the deformable spoke wheel mechanism of the present invention;

[0022] Figure 3 This is another perspective schematic diagram of the overall structure of the deformable spoke wheel mechanism of the present invention;

[0023] Figure 4 This is an exploded view of the overall structure of the deformable spoke wheel mechanism of the present invention from another perspective;

[0024] Figure 5 This is a front view of the deformable spoke wheel mechanism of the present invention;

[0025] Figure 6 This is a three-dimensional schematic diagram of the overall structure of the present invention in a wheel-like configuration;

[0026] Figure 7 This is a three-dimensional schematic diagram of the overall structure of the present invention in a leg-like configuration.

[0027] In the diagram: 1-Car body, 2-Motor 1, 3-Electric slip ring, 4-Drive shaft, 5-Bearing, 6-Inner hub, 7-Triangle frame, 8-Deformable wheel, 9-Connecting rod, 10-Driving gear, 11-Driven gear, 12-Fixing plate, 13-Fixing rod, 14-Outer hub, 15-Motor transmission rod, 16-Motor 2. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] like Figures 1 to 5As shown, a bidirectional deformable and isotropic spoked wheel mechanism includes a motor 2 and an electric slip ring 3 fixedly mounted on a vehicle body 1. A transmission shaft 4 is coaxially fixed on the drive shaft of the motor 2. The transmission shaft 4 passes through the electric slip ring 3 and rotates synchronously with the rotor of the electric slip ring. A bearing 5 is mounted on the vehicle body 1. The transmission shaft 4 can rotate relative to the vehicle body 1 through the bearing 5. An inner hub 6 is coaxially fixed to one end of the rotating shaft 4. When the motor 2 starts, it can drive the inner hub 6 to rotate.

[0030] A triangular frame 7 is fixed on the inner hub 6, and the central axis of the triangular frame 7 coincides with the axis of the drive shaft 4. Three cylinders are evenly distributed circumferentially on the triangular frame 7, and a driven gear 11 is rotatably connected to each cylinder. The driven gears 11 are respectively mounted and limited on the triangular frame 7 by three fixing plates 12. A driving gear 10 is rotatably connected at the center of the triangular frame 7. The three driven gears 11 are evenly distributed around the driving gear 10 and mesh with the driving gear 10. A deformable wheel 8 is coaxially arranged on one side of the inner hub 6. The deformable wheel 8 includes three arc segments corresponding to the driven gears 11. Two connecting rods 9 are installed between the arc segment and the driven gear 11. One end of the connecting rod 9 is hinged to the arc segment, and the other end is rotatably connected to the driven gear 11. The two connecting rods 9 are connected to the driven gear 11 and the arc segment on both sides respectively, forming a parallelogram structure. A fixed rod 13 is rotatably connected to the middle position of each arc segment. An outer hub 14 is coaxially arranged on the side of the deformable wheel 8 facing away from the inner hub 6. All three fixed rods 13 are fixedly connected to the outer hub 14. A second motor 16 is fixed on the outer hub 14. A motor transmission rod 15 is coaxially fixed on the drive shaft of the second motor 16. The motor transmission rod 15 is fixed to the driving gear 10.

[0031] When motor 216 is running, it can drive the drive gear 10 to rotate, thereby driving the three driven gears 11 to rotate. Under the connecting action of the connecting rod 9, the three arc segments on the deformable wheel 8 rotate toward the fixed rod 13, so that the three arc segments no longer form a wheel shape (as shown in the image). Figure 7 (As shown), thus switching to leg mode.

[0032] It is worth mentioning that in this embodiment, the transmission ratio between the driving gear 10 and the driven gear 11 is 15:18. The design concept is as follows: the module of both the driving gear 10 and the driven gear 11 is 2. Since the driven gear 11 needs to form an equilateral triangle, the number of teeth of the driving gear 10 in the middle should be set to a multiple of 3. Based on the final size of the wheel, it is set to 15 teeth. The two cylinders on the driven gear 11 are located on both sides of the central hole. The number of teeth of the driven gear 11 should be set to a multiple of 2. Considering the torque and the size of the wheel, it is set to 18 teeth.

[0033] In addition, in this embodiment, the function of the slip ring 3 is to provide power and control signals to the motor 16 installed on the outer hub 14.

[0034] Working principle:

[0035] When the spoked wheel is in such a state Figure 5 and 6 In the wheel mode shown (in the figure, "+" indicates the positive direction of rotation and "-" indicates the negative direction of rotation), by locking motor 12, the inner hub 6 is kept stationary, and motor 216 drives the drive gear 10 to rotate in the positive direction. The driven gear 11 rotates in the opposite direction relative to the cylinder around the tripod 7. The connecting rod 9 rotates in the positive direction relative to the driven gear 11 on one side. The deformable wheel 8 rotates in the opposite direction relative to the fixed rod 13, thereby causing the deformable wheel 8 to unfold counterclockwise. The fixing plate 12 used to fix the driven gear 11, when the driven gear 11 controls the deformable wheel 8 to rotate through a certain angle, the connecting rod 9 contacts the outer circle of the fixing plate 12, thereby limiting the rotation range of the deformable wheel 8, that is, realizing the counterclockwise switching of the deformable spoke wheel mechanism from wheel mode to leg mode.

[0036] In the aforementioned leg mode, by locking motor 12 and keeping the inner hub 6 stationary, motor 216 drives the drive gear 10 to rotate in the opposite direction, the driven gear 11 rotates in the positive direction relative to the cylinder around the tripod 7, the connecting rod 9 rotates in the opposite direction relative to the driven gear 11 on one side, and the deformable wheel 8 rotates in the positive direction relative to the fixed rod 13, thereby causing the deformable wheel 8 to retract, thus realizing the switching of the deformable spoke wheel mechanism from leg mode to wheel mode.

[0037] In wheel mode, by locking motor 12 to keep the inner hub 6 stationary, motor 216 drives the drive gear 10 to rotate in the opposite direction, the driven gear 11 rotates in the positive direction relative to the cylinder around the tripod 7, the connecting rod 9 rotates in the opposite direction relative to the driven gear 11 on one side, and the deformable wheel 8 rotates in the positive direction relative to the fixed rod 13, thereby causing the deformable wheel 8 to unfold clockwise; the fixing plate 12 used to fix the driven gear 11, when the driven gear 11 controls the deformable wheel 8 to rotate through a certain angle, the connecting rod 9 contacts the fixing plate 12, thereby limiting the rotation range of the deformable wheel 8, that is, realizing the clockwise switching of the deformable spoke wheel mechanism from wheel mode to leg mode.

[0038] In the aforementioned leg mode, the inner hub 6 remains stationary, and the control motor 16 drives the drive gear 10 to rotate in the positive direction. The driven gear 11 rotates in the opposite direction relative to the cylinder around the tripod 7. The connecting rod 9 rotates in the positive direction relative to the driven gear 11 on one side. The deformable wheel 8 rotates in the opposite direction relative to the fixed rod 13, thereby causing the deformable wheel 8 to retract. This achieves the switching of the deformable spoke wheel mechanism from leg mode to wheel mode.

[0039] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A bidirectional deformable and isotropic spoked wheel mechanism, mounted on one side of a vehicle body (1), characterized in that, It includes a drive shaft (4) rotatably mounted on the vehicle body (1), an inner hub (6) coaxially fixed at the end of the drive shaft (4), a triangular frame (7) fixed on one side of the inner hub (6), the central axis of the triangular frame (7) coincides with the axis of the drive shaft (4), three cylinders evenly distributed in the circumference are provided on the triangular frame (7), a driven gear (11) is rotatably connected on each cylinder, and a driving gear (10) is rotatably connected at the center of the triangular frame (7), and all three driven gears (11) mesh with the driving gear (10); A deformable wheel (8) is coaxially arranged on one side of the inner hub (6). The deformable wheel (8) includes three arc segments. Two connecting rods (9) are installed between each arc segment and the driven gear (11). One end of the connecting rod (9) is hinged to the arc segment, and the other end is rotatably connected to the driven gear (11). A fixed rod (13) is rotatably connected at the middle position of each arc segment. An outer hub (14) is coaxially arranged on one side of the deformable wheel (8). The fixed rod (13) is fixedly connected to the outer hub (14). A motor (16) is fixed on the outer hub (14) to drive the drive gear (10) to rotate. Each driven gear (11) is provided with a fixing plate (12), which can limit the flipping position of the connecting rod (9); the connecting rod (9) contacts the outer circle of the fixing plate (12), thereby limiting the rotation range of the deformable wheel (8); The transmission ratio of the driving gear (10) to the driven gear (11) is 5:

6.

2. The spoked wheel mechanism that is bidirectionally deformable and isotropic according to claim 1, characterized in that, A motor (2) is installed on the vehicle body (1), and the transmission shaft (4) is rotatably connected to the vehicle body (1). The motor (2) drives the transmission shaft (4) to rotate.

3. The spoked wheel mechanism that is bidirectionally deformable and isotropic according to claim 2, characterized in that, A bearing (5) is installed on the vehicle body (1), and the drive shaft (4) is rotatably connected to the vehicle body (1) through the bearing (5).

4. The spoked wheel mechanism that is bidirectionally deformable and isotropic according to claim 1, characterized in that, A motor transmission rod (15) is coaxially fixed on the drive shaft of motor 2 (16), and the motor transmission rod (15) is fixed to the drive gear (10).

5. A bidirectional deformable and isotropic spoked wheel mechanism according to claim 2, characterized in that, An electric slip ring (3) is fixed on the vehicle body (1), and the drive shaft (4) passes through the electric slip ring (3) and rotates synchronously with the rotor of the electric slip ring (3).

6. A robot, comprising a vehicle body (1), characterized in that, It also includes the spoked wheel mechanism as described in any one of claims 1-5.

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