A local omni-directional wheel chassis structure

Abstract

The application relates to a local omnidirectional wheel chassis structure. The local omnidirectional wheel chassis structure comprises a frame body, a front axle assembly and a rear axle assembly connected to the frame body, the front axle assembly and the rear axle assembly each comprising two groups of hub motors, the hub motors constituting front wheels and rear wheels respectively, and the hub motors being fixedly connected with roller assemblies at notch positions, the roller assemblies at least comprising roller pieces capable of rotating around their own axes, the number of the roller pieces being at least two groups, and the roller pieces being capable of rotating around their own axes and pointing to the center of the front axle, that is, the rotation center of the whole machine when the roller pieces are at the lowest positions of the rear wheels; compared with other omnidirectional wheel chassis structures, the local omnidirectional wheel chassis structure greatly improves the obstacle climbing and slope climbing performance.

Description

Technical Field

[0001] This invention belongs to the field of inspection robot technology, specifically relating to a partial omnidirectional wheel chassis structure. Background Technology

[0002] In existing technologies, the steering wheels of the chassis of inspection robots are generally arranged in an alternating pattern of two discs with small rollers to achieve omnidirectional wheel function. That is, the wheel unit itself can slide laterally without wear at any angle without affecting normal rolling straight movement. Based on this, a three-wheeled or four-wheeled omnidirectional mobile chassis can be constructed. Alternatively, a combination of large and small wheels can be arranged circumferentially, with a circle of large and small wheels arranged on a disc to achieve omnidirectional wheel function. Based on this, a near-omnidirectional mobile chassis with front drive wheels and rear omnidirectional wheels can be constructed.

[0003] However, for the former, the three-wheel or four-wheel omnidirectional wheel chassis, due to the large number of small rollers, the failure rate is high, making it unsuitable for outdoor working conditions. Furthermore, the overall stability of the chassis is poor, and it is likely to skid when traveling on slopes. For the latter, in the front-wheel drive, rear-wheel omnidirectional wheel chassis, the omnidirectional wheels also have a high failure rate, making it unsuitable for outdoor working conditions. Moreover, for the front-wheel drive chassis, the obstacle crossing and climbing performance has its physical limits, which are far lower than that of the four-wheel drive chassis. This type of solution lacks stability on slopes and is prone to fishtailing when climbing at an angle.

[0004] The technical problem to be solved by this application is to ensure that the chassis’s climbing and obstacle-crossing performance is no less than that of a four-wheel drive chassis while using a partial omnidirectional wheel structure to achieve near omnidirectional movement. At the same time, it avoids the disadvantages of omnidirectional wheels having many small rollers, high failure rate, and unsuitability for outdoor working conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a simple and reasonably designed partially omnidirectional wheel chassis structure to solve the above problems.

[0006] The present invention achieves the above objectives through the following technical solutions:

[0007] A partially omnidirectional wheel chassis structure includes a frame body, which is further connected to a front axle assembly and a rear axle assembly. Each of the front and rear axle assemblies includes two sets of hub motors, which respectively constitute the front wheel and the rear wheel. A roller assembly is fixedly connected to the notch position of the hub motor. The roller assembly includes at least two roller components that can rotate around their own axis. When the roller component is at the lowest position of the rear wheel, the rotation axis of the roller component points to the center of the front axle, which is also the rotation center of the entire machine.

[0008] As a further optimization of the present invention, the roller assembly further includes a fixing frame, the fixing frame is connected to a pin, the roller is sleeved on the surface of the pin, and a bearing is provided between the roller and the pin.

[0009] As a further optimization of the present invention, the bearing component is a contact-sealed deep groove ball bearing.

[0010] As a further optimization of the present invention, a gasket is provided on the outer side of the bearing component.

[0011] As a further optimization of the present invention, the front axle assembly further includes a front axle rod connecting the two front wheels, and a front axle damping spring is provided between the front axle rod and the vehicle frame. The rear axle assembly further includes a rear axle rod, and a rear axle damping spring is also provided between the rear axle rod and the vehicle frame.

[0012] As a further optimization of the present invention, the vehicle frame is also connected to a sensor switch.

[0013] A second aspect of the present invention provides an omnidirectional wheel body, the wheel body including a roller assembly fixedly connected to the wheel body, the roller assembly including at least a roller member rotatable about its own axis, the roller member being at the lowest position of the rear wheel, the roller member’s own rotation axis pointing to the center of the front axle, that is, the rotation center of the whole machine.

[0014] The beneficial effects of the present invention are as follows: the chassis layout of the omnidirectional wheel structure of the present invention omits the external drive motor, reducer structure and steering structure, while still ensuring near omnidirectional driving function; it avoids the disadvantage of high failure rate caused by the large number of small rollers in omnidirectional wheels, which makes it difficult to apply in outdoor working conditions; compared with other omnidirectional wheel chassis structures, it greatly enhances obstacle crossing and climbing performance. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 This is the invention Figure 1 A schematic diagram of the side structure;

[0017] Figure 3 This is a schematic diagram of the structure of the present invention after removing one set of rear wheels;

[0018] Figure 4 This is a structural schematic diagram from the tail view of the present invention;

[0019] Figure 5 This is a top-view structural diagram of the present invention.

[0020] In the diagram: 1. Chassis; 2. Front axle assembly; 21. Front axle rod; 22. Front axle damping spring; 3. Rear axle assembly; 31. Rear axle rod; 32. Rear axle damping spring; 4. Roller assembly; 41. Mounting bracket; 42. Roller component; 43. Pin; 5. Inductive switch. Detailed Implementation

[0021] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0022] Example 1

[0023] like Figures 1 to 5 As shown, a partially omnidirectional wheel chassis structure includes a frame body 1. The frame body 1 is also connected to a front axle assembly 2 and a rear axle assembly 3. Both the front axle assembly 2 and the rear axle assembly 3 include two sets of hub motors. The hub motors respectively constitute the front wheel and the rear wheel. A roller assembly 4 is fixedly connected to the notch position of the hub motor. The roller assembly 4 includes at least two sets of roller components 42 that can rotate around their own axis. When the roller component 42 is at the lowest position of the rear wheel, the rotation axis of the roller component 42 points to the center of the front axle, which is also the rotation center of the whole machine.

[0024] Furthermore, the roller assembly 4 also includes a fixing frame 41, the fixing frame 41 is connected to a pin 43, the roller component 42 is sleeved on the surface of the pin 43, and a bearing component is also provided between the roller component 42 and the pin 43.

[0025] Specifically, the bearing component is a contact-sealed deep groove ball bearing.

[0026] In fact, a gasket is provided on the outside of the bearing component.

[0027] It should also be noted that the front axle assembly 2 further includes a front axle rod 21 connecting the two front wheels, and a front axle damping spring 22 is provided between the front axle rod 21 and the vehicle frame 1. The rear axle assembly 3 further includes a rear axle rod 31, and a rear axle damping spring 32 is also provided between the rear axle rod 31 and the vehicle frame 1.

[0028] Furthermore, the vehicle frame 1 is also connected to an induction switch 5.

[0029] It should be noted that in actual use, the roller assembly 4 is fixed to the notched hub motor with bolts, and the roller component 42 is aligned with the notch on the hub motor wheel surface to form a complete rolling circle; the inductive switch 5 is fixed to the frame and is aligned with the notch position of the notched hub motor 5; the left and right ends of the roller component 42 are respectively assembled with the outer ring of a contact-type sealed deep groove ball bearing, and the pin 43 passes through the inner rings of the two contact-type sealed deep groove ball bearings and through the two shaft holes of the fixing frame 4, thereby connecting the roller component 42 to the fixing frame 4 and enabling them to rotate. For rotation, while the rolling axis of roller component 42 is at an angle of 90° relative to the rolling axis of the notched hub motor, an additional offset angle is added based on the front and rear wheelbase and the left and right wheel track of the chassis, so that the rolling axis of roller component 42 points to the midpoint of the two front wheels; the shim is inserted on the pin 43 and placed on the outside of the two left and right contact-sealed deep groove ball bearings to protect the contact-sealed deep groove ball bearings from rubbing against the fixed frame 4; the front axle assembly 2 and the rear axle assembly 3 are hinged to the frame body 1 as shown in the figure through axle shoulder bolts, copper sleeves and copper washers and connected with shock absorbers. Among them, the front axle assembly 2 has two ordinary hub motors, and the rear axle assembly 31 contains two partial omnidirectional wheel chassis structure hub motors.

[0030] In actual use, the front axle assembly 2 and the rear axle assembly 3 provide the necessary support for the entire machine. The hub motor provides traction, and the pressure provided by the shock absorbers ensures grip in various motion environments, ensuring that the hub motor is in constant contact with the ground, while simultaneously filtering out vibration input from uneven ground.

[0031] When the robot chassis needs to travel in a straight line, the four sets of hub motors rotate in the same direction to satisfy forward or backward movement. When the robot chassis needs to make a small change of direction while moving, the outer wheels increase speed and the inner wheels decrease speed by a certain amount based on the rotation of the four sets of hub motors in the same direction to achieve directional adjustment. When the robot chassis needs to perform a near-stationary turn, the two partial omnidirectional wheel hub motors of the rear axle assembly 3 are first adjusted to a specific angle with the cooperation of inductive switches, so that the roller component 42 touches the ground. Then, the two sets of hub motors of the front axle assembly 2 rotate at different speeds, and the chassis rotates with the midpoint of the two hub motors of the front axle assembly 2 as the center. The roller component 42 of the partial omnidirectional wheel hub motor of the rear axle assembly 3 rotates in coordination, so that the omnidirectional wheel itself makes an oblique movement to cooperate with the rotation of the whole machine.

[0032] It should be further explained that the inductive switch 5 mainly detects the position of the roller component 42. An image sensor or other sensors can be used in conjunction with corresponding markers to determine the position of the roller component 42, ensuring that the roller component 42 can touch the ground when a U-turn is required. In this embodiment, the inductive switch 5 can be a cylindrical threaded magnetic inductive switch with a sensing distance of 5mm. It is set that when it is triggered, the roller component 42 contacts the ground. That is, when a U-turn is required, the device needs to travel a short distance forward or backward until the magnetic inductive switch receives a signal and the roller component 42 is grounded before the U-turn can be performed.

[0033] The number of roller components 42 is based on the stability of the hub, and there should be at least two sets. In actual use, there can also be multiple sets, as long as they are evenly distributed at the center of the hub.

[0034] It should also be noted that in actual use, when the robot's patrol route is relatively narrow and it needs to turn immediately upon reaching a turning point without any room to move forward or backward, it is necessary to increase the number of small roller pairs. Taking a wheel diameter of 300mm as an example, when the number of roller pairs (42mm) is increased to two, the robot can move a maximum of 300*3.14 / 4 / 2=118mm, which is sufficient to prepare for a turn on the spot.

[0035] When turning in place, the front left and right wheels rotate in opposite directions at the same speed, while the rear wheel hub motor body remains stationary at 0 speed, and the grounding roller rotates at a speed of...

[0036] ω x =ω c *Lr / ri;

[0037] Where, ω c —The rotational angular velocity of the entire machine, in rad / s;

[0038] Lr—From a top view, the distance from the center of the rear wheel to the center of the two front wheels, i.e., the center of rotation of the entire machine, in meters;

[0039] ri — the cross-sectional radius of the contact point between the grounding roller and the ground, in meters.

[0040] Example 2

[0041] Based on Embodiment 1, an omnidirectional wheel body is further proposed. The wheel body includes a roller assembly 4 fixedly connected to the wheel body. The roller assembly 4 includes at least a roller member 42 that can rotate around its own axis. When the roller member 42 is at the lowest position of the rear wheel, its own rotation axis points to the center of the front axle, which is also the rotation center of the whole machine.

[0042] It should be noted that, in use, the chassis layout of this partial omnidirectional wheel structure omits the external drive motor, reducer structure, and steering structure, while still ensuring near-omnidirectional driving function; it avoids the disadvantages of high failure rate caused by a large number of small rollers in omnidirectional wheels, making it difficult to apply in outdoor conditions; compared with other omnidirectional wheel chassis structures, it greatly enhances obstacle crossing and climbing performance.

[0043] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A partially omnidirectional wheel chassis structure, characterized in that, The vehicle includes a frame body (1), which is also connected to a front axle assembly (2) and a rear axle assembly (3). Both the front axle assembly (2) and the rear axle assembly (3) include two sets of hub motors, which respectively constitute the front wheel and the rear wheel. A roller assembly (4) is fixedly connected to the notch of the hub motor. The roller assembly (4) and the notch of the hub motor together form a complete rolling circle. The roller assembly (4) includes at least two roller components (42) that can rotate around their own axis. The number of roller components (42) is at least two. When the roller component (42) is at the lowest position of the rear wheel, the roller component (42) The self-rotation axis of the chassis (1) points to the center of the front axle, which is also the rotation center of the whole machine; the chassis body (1) is also connected to an induction switch (5); when the chassis needs to turn around in an almost stationary manner, the two hub motors of the rear axle assembly (3) are first adjusted to a specific angle through the cooperation of the induction switch (5) so that the roller (42) touches the ground, and then the two sets of hub motors of the front axle assembly (2) rotate at different speeds. The chassis rotates with the midpoint of the hub motors of the two front axle assemblies (2) as the center. The roller (42) in the hub motor of the rear axle assembly (3) rotates in cooperation, so that the omnidirectional wheel itself makes an oblique movement to cooperate with the whole machine to rotate.

2. The partial omnidirectional wheel chassis structure according to claim 1, characterized in that: The roller assembly (4) also includes a fixing frame (41), the fixing frame (41) is connected to a pin (43), the roller component (42) is sleeved on the surface of the pin (43), and a bearing component is also provided between the roller component (42) and the pin (43).

3. The partial omnidirectional wheel chassis structure according to claim 2, characterized in that: The bearing component is a contact-sealed deep groove ball bearing.

4. The partial omnidirectional wheel chassis structure according to claim 3, characterized in that: A gasket is provided on the outer side of the bearing component.

5. A partially omnidirectional wheel chassis structure according to claim 4, characterized in that: The front axle assembly (2) also includes a front axle rod (21) connecting the two front wheels, and a front axle damping spring (22) is provided between the front axle rod (21) and the vehicle frame (1). The rear axle assembly (3) also includes a rear axle rod (31), and a rear axle damping spring (32) is also provided between the rear axle rod (31) and the vehicle frame (1).

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