A decoupled active universal wheel assembly for precision driving and omnidirectional mobile platform

Abstract

The application discloses a decoupling active universal wheel assembly for precise driving, which comprises a box, a wheel frame freely turning downwardly installed on the box, a first roller and a second roller located on both sides of the wheel frame, and a first wheel shaft and a second wheel shaft for driving the first roller and the second roller to roll respectively, wherein the box is internally provided with a driving device for providing driving force for the first wheel shaft and the second wheel shaft and a turning device for controlling the turning of the wheel frame. The application further provides an omnidirectional mobile platform. The method provided by the application introduces a clearance-eliminating structure for the universal wheel assembly to eliminate the rolling output derived when the caster turns, so that the motion precision and flexibility of the caster are improved.

Description

Technical Field

[0001] This invention relates to the field of mobile robot technology, and in particular to a decoupled active omnidirectional wheel assembly and an omnidirectional mobile platform for precision drive. Background Technology

[0002] In recent years, in order to improve production efficiency and reduce labor costs, the requirements for industrial automation and intelligence in fields such as equipment manufacturing have been continuously increasing, leading to the increasingly widespread application of mobile robots. Omnidirectional wheeled mobile robots are particularly favored due to their ease of manufacturing compared to legged mobile robots, high load-bearing capacity and efficiency, flexible movement, and ability to operate in narrow and crowded environments.

[0003] Active omnidirectional casters, as the locomotion mechanism of omnidirectional wheeled mobile robots, are typically equipped with two drive motors: one for driving the wheels to roll and the other for driving them to steer. To prevent cables from getting tangled during movement, the two motors are usually fixed to the base of the caster. In this case, the drive axis and steering axis of the roller are perpendicular to each other, which will generate coupled motion during movement, affecting motion stability and increasing the difficulty of control.

[0004] Patent document CN111674201A discloses an active power caster assembly for mobile robots. It introduces an additional decoupling mechanism into the caster's motion transmission system. This allows the steering motor to output a separate motion while simultaneously outputting steering motion, eliminating the coupling problem between the caster's steering and rolling motions. Therefore, kinematic decoupling of the caster can be achieved simply by setting appropriate transmission parameters. While this method solves the motion coupling problem, the introduced planetary gear system inevitably generates backlash during installation, leading to delayed motion transmission and reduced caster control accuracy. Furthermore, the impact between the planetary gears reduces gear life and increases uncertainty during operation.

[0005] Patent document CN111828557A discloses a backlash-eliminating planetary gear reducer that generates a preload between gears by installing elastic elements (springs, torsion springs) in the planetary gear train, thereby eliminating the influence of gear backlash. However, since the preload generated by springs and torsion springs relies on their own elastic properties, it is not easily controlled manually; furthermore, due to the elastic limit of springs, elastic failure may occur. Therefore, using such a passive compliant mechanism as elastic elements (springs, torsion springs) to eliminate gear backlash still presents many uncertainties. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a decoupled active swivel caster assembly that eliminates the rolling output derived when the caster turns, thereby improving the caster's motion accuracy and flexibility.

[0007] A decoupled active omnidirectional wheel assembly for precision drive includes a housing, a wheel frame that can freely turn under the housing, a first roller and a second roller located on both sides of the wheel frame, and a first wheel axle and a second wheel axle that drive the first roller and the second roller respectively. The housing is provided with a drive device that provides driving force to the first wheel axle and the second wheel axle and a steering device for controlling the steering of the wheel frame.

[0008] The driving device includes a drive motor, a decoupling mechanism, a drive gear set, and a differential gear set. The driving force output by the drive motor is decoupled through the decoupling mechanism, and the decoupled driving force is output to the first axle and the second axle in conjunction with the drive gear set and the differential gear set.

[0009] The steering device includes a steering motor, a steering gear set, and a steering mechanism for controlling the rotation of the wheel frame. The rotational force output by the steering motor is output to the decoupling mechanism and the steering mechanism through the steering gear set. The decoupling mechanism decouples the rolling output derived when the rollers turn.

[0010] When moving straight, the axles on both sides drive their respective rollers to roll at the same speed. When turning, the axles on both sides drive their respective rollers to roll at different speeds, thus ensuring stable movement.

[0011] The present invention adds a decoupling mechanism to the drive device. Through the active compliant gear backlash elimination structure in the decoupling mechanism, the rolling output derived when the caster turns is eliminated, thereby improving the motion accuracy of the caster and avoiding impact wear between the teeth.

[0012] Specifically, the steering gear set includes a first gear, a second gear, a third gear, and a fourth gear. The first gear and the second gear are coaxially fixedly mounted on the output shaft of the steering motor. The third gear and the fourth gear are coaxially mounted on the inner side wall of the housing. The third gear meshes externally with the first gear and rotates synchronously. The fourth gear meshes externally with the second gear and rotates synchronously. The wheel frame is fixedly mounted below the fourth gear.

[0013] Specifically, the decoupling mechanism includes a fifth gear mounted on the output shaft of the drive motor, a sixth gear arranged coaxially opposite to the fifth gear, a backlash-free gear set arranged between the fifth and sixth gears for transmitting driving force, and a rolling output shaft fixedly connected to the backlash-free gear set, wherein the rolling output shaft is mounted coaxially with the sixth gear.

[0014] Specifically, the backlash-free gear set includes one or more gear sets, a force sensor for acquiring the meshing force between the gears, and a linear actuator for adjusting the meshing force between the gears. The gear set includes a first gear connecting shaft, a seventh gear and an eighth gear fixed at both ends of the first gear connecting shaft, a second gear connecting shaft, and a ninth gear and a tenth gear fixed at both ends of the second gear connecting shaft. The first gear connecting shaft and the second gear connecting shaft are arranged alternately. One end of the force sensor is fixed to the first gear connecting shaft, and the other end is fixed to the stator of the linear actuator. The mover of the linear actuator is fixed to the second gear connecting shaft.

[0015] Specifically, the gear set is connected as follows: the first bolt and the second bolt can be inserted into the non-intermediate holes of the first connecting shaft and the second connecting shaft respectively, and cooperate with the first nut and the second nut respectively. The first connecting piece and the second connecting piece are installed coaxially with the through holes at the non-intermediate positions of the first connecting shaft and the second connecting shaft respectively, so that the first connecting piece and the second connecting piece can rotate relative to the non-intermediate holes of the first connecting shaft and the second connecting shaft respectively.

[0016] Specifically, the drive gear set includes: an eleventh gear, a twelfth gear, a thirteenth gear, a fourteenth gear, and a fifteenth gear. The eleventh gear is fixed to the rolling output shaft and rotates synchronously. The twelfth and thirteenth gears are coaxially mounted with the first rotating shaft of the steering mechanism and are respectively fixed on the first rotating shaft of the steering mechanism and rotate synchronously. The fourteenth gear is fixed on the inner side wall of the wheel frame and rotates relative to it. The fifteenth gear is mounted on the wheel axle and rotates relative to it.

[0017] Specifically, the differential gear set includes: a differential gearbox, a sixteenth gear, a seventeenth gear, an eighteenth gear, and a nineteenth gear. The differential gearbox is fixed to the tooth side surface of the fifteenth gear to maintain synchronous rotation. The sixteenth and eighteenth gears are arranged coaxially on the side of the differential gearbox to ensure rotation. The seventeenth and nineteenth gears are fixed coaxially on one end of the shaft wheel. The seventeenth gear meshes with the sixteenth and eighteenth gears respectively, and the nineteenth gear meshes with the sixteenth and eighteenth gears respectively.

[0018] Specifically, there is a preset distance between the vertical diameter line of the roller and the axis of the output shaft of the drive motor.

[0019] The present invention also provides an omnidirectional mobile platform, including a storage platform and at least three decoupled active caster wheel assemblies as described in claims 1 to 7. The storage platform includes a storage plate, a base box, and a lifting mechanism for changing the height of the storage plate. A plurality of springs for buffering are provided between the storage plate and the base box. The decoupled active caster wheel assemblies are arranged inside the base box.

[0020] Specifically, the base plate box is also equipped with a depth sensor and an tilt sensor for feedback of movement position. The depth sensor is used to determine the distance between the side of the base plate box and the obstacle, and the tilt sensor is used to determine the angle between the placement plate and the horizontal plane, thereby feeding back relevant data to determine the next movement path.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] (1) Add a decoupling mechanism to the drive unit to eliminate the rolling output effect derived when the caster turns.

[0023] (2) An active compliant gear backlash elimination mechanism is introduced into the decoupling mechanism to improve the motion accuracy of the caster and eliminate inter-tooth impact. Attached Figure Description

[0024] Figure 1 An isometric view of the decoupled active omnidirectional wheel assembly provided by the present invention;

[0025] Figure 2 Side view of the decoupled active omnidirectional wheel assembly;

[0026] Figure 3 Schematic diagram for decoupling the active omnidirectional wheel assembly;

[0027] Figure 4 Axonometric view of the decoupled active omnidirectional wheel assembly after removing the outer casing;

[0028] Figure 5 Front view of the decoupled active omnidirectional wheel assembly after removing the housing;

[0029] Figure 6 A three-dimensional structural diagram of a gear set with backlash elimination function;

[0030] Figure 7 A top view of a gear set with backlash elimination function;

[0031] Figure 8 An isometric view of the omnidirectional mobile platform provided by the present invention;

[0032] Figure 9 Axonometric view of the omnidirectional mobile platform after removing the outer shell:

[0033] Figure 10 A side view of an omnidirectional mobile platform;

[0034] In the diagram: 10, First roller; 20, Second roller; 30, Second axle; 40, First axle; 50, First fixed shaft; 60, First rotating shaft; 70, Bogie; 80, Steering device; 81, Steering motor; 82, Steering gear set; 821, First gear; 822, Second gear; 823, Third gear; 824, Fourth gear; 90, Drive device; 91, Drive motor; 92, Decoupling mechanism; 921, Fifth gear; 922, Sixth gear; 923, Backlash-free gear set; 9231, Gear set; 92311, Seventh gear; 92312, First gear connecting shaft; 92313, Eighth gear; 92314, Ninth gear; 923 15. Second gear connecting shaft; 92316. Tenth gear; 924. Rolling output shaft; 93. Drive gear set; 931. Eleventh gear; 932. Twelfth gear; 933. Thirteenth gear; 934. Fourteenth gear; 935. Fifteenth gear; 94. Differential gear set; 941. Differential gearbox; 942. Sixteenth gear; 943. Seventeenth gear; 944. Eighteenth gear; 945. Nineteenth gear; 100. Base; 110. Shelf plate; 120. Ball joint connection device; 130. Spring; 140. Middle plate; 150. Through hole; 160. Base plate; 170. Lifting mechanism; 180. Tilt sensor; 190. Depth sensor. Detailed Implementation

[0035] 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.

[0036] like Figures 1 to 7 As shown, the present invention provides a decoupled active omnidirectional wheel assembly, including a drive device 90, a steering device 80, a first roller 10, a second roller 20, a first wheel axle 40, a second wheel axle 30, a first fixed shaft 50, a first rotating shaft 60, a bogie 70, and a base 100. The first rotating shaft 60 is connected to the bogie 70 via bearings, and the first fixed shaft 50 is fixedly connected to the bogie 70. The first wheel axle 40 and the second wheel axle 30 pass through the first roller 10 and the second roller 20, respectively, and are mounted on the bogie 70 via bearings. The first wheel axle 40 rotates synchronously with the first roller 10, and the second wheel axle 30 rotates synchronously with the second roller 20. The drive device 90 and the steering device 80 are respectively mounted on the base 100.

[0037] The drive unit 90 includes a drive motor 91, a decoupling mechanism 92, a drive gear set 93, and a differential gear set 94. The drive motor 91 is mounted on the base 100. The drive motor 91 drives the decoupling mechanism 92 and the drive gear set 93, and inputs power to the differential gear set 94. The differential gear set 94 outputs power through the first wheel axle 40 and the second wheel axle 30. When the caster is moving straight, the first wheel axle 40 drives the first roller 10, and the second wheel axle 30 drives the second roller 20 to roll at the same speed; or the first wheel axle 40 drives the first roller 10, and the second wheel axle 30 drives the second roller 20 to roll at different speeds.

[0038] The steering device 80 includes a steering motor 81 and a steering gear set 82. The steering motor 81 is mounted on the base 100. The motion output by the steering motor 81 is divided into two parts by the steering gear set 82. One part is input to the decoupling mechanism 92 to decouple the rolling output derived when the first roller 10 and the second roller 20 are turning. The other part is used to drive the bogie 70 to turn, thereby controlling the movement direction of the first roller 10 and the second roller 20.

[0039] The decoupling mechanism 92 includes a fifth gear 921, a sixth gear 922, a gear set 923 with backlash elimination function, and a rolling output shaft 924. The fifth gear 921 is fixedly mounted on the output shaft of the drive motor 91. The sixth gear 922 is coaxially mounted with the fifth gear 921 and is mounted on the base 100 via bearings. The gear set 923 with backlash elimination function is installed between the fifth gear 921 and the sixth gear 922 and meshes with both gears. The rolling output shaft 924 is coaxially mounted with the sixth gear 922 and is fixedly connected to the gear set 923 with backlash elimination function to maintain synchronous rotation.

[0040] The backlash-free gear set 923 includes at least one set: gear set 9231, first bolt 9232, first nut 9233, first connector 9234, force sensor 9235, linear actuator 9236, second connector 9237, second bolt 9238, and second nut 9239; if it includes multiple sets, they must be arranged in a centrally symmetrical manner with the rotating output shaft 924 as the center, according to the above installation method.

[0041] The gear set 9231 includes: a seventh gear 92311, a first gear connecting shaft 92312, an eighth gear 92313, a ninth gear 92314, a second gear connecting shaft 92315, and a tenth gear 92316. The first gear connecting shaft 92312 is fixedly connected to both the seventh gear 92311 and the eighth gear 92313. The second gear connecting shaft 92315 is fixedly connected to both the ninth gear 92314 and the tenth gear 92316. The first gear connecting shaft 92312 and the second gear connecting shaft 92315 are rotatable relative to each other. A through hole is formed between the first gear connecting shaft 92312 and the second gear connecting shaft 92315. A rolling output shaft 924 passes through this through hole and is fixedly connected to the gear set 923, maintaining synchronous rotation. A through hole is also formed between the first gear connecting shaft 92312 and the second gear connecting shaft 92315 at a non-central position.

[0042] Simultaneously, the first bolt 9232 and the second bolt 9238 can be inserted into the through holes of the first gear connecting shaft 92312 and the second gear connecting shaft 92315 at non-intermediate positions, respectively, and cooperate with the first nut 9233 and the second nut 9239, respectively, to install the first connecting piece 9234 and the second connecting piece 9237 coaxially with the through holes of the first gear connecting shaft 92312 and the second gear connecting shaft 92315 at non-intermediate positions, so that the first connecting piece 9234 and the second connecting piece 9237 rotate relative to the through holes of the first gear connecting shaft 92312 and the second gear connecting shaft 92315 at non-intermediate positions.

[0043] Furthermore, the first connector 9234, the force sensor 9235, the linear actuator 9236, and the second connector 9237 are located on the same plane. The linear actuator 9236 consists of a stator and a mover. One end of the force sensor 9235 is fixedly connected to the first connector 9234, and the other end is fixedly connected to the stator of the linear actuator 9236. The mover of the linear actuator 9236 is fixedly connected to the second connector 9237.

[0044] Among them, the force sensor 9235 can measure the meshing force between the seventh gear 92311, the eighth gear 92313, the ninth gear 92314, the tenth gear 92316 and the fifth gear 921 and the sixth gear 922. By adjusting the positional relationship between the stator and the mover of the linear actuator 9236, the meshing force between the gear set 9231 and the fifth gear 921 and the sixth gear 922 can be adjusted, thereby eliminating the backlash between the gear teeth, improving the transmission accuracy, reducing the impact force between the gears, and extending the gear life.

[0045] Let surface A be the plane that passes vertically through the central axis of the linear actuator 9236 and the rolling output shaft 924. When the decoupling mechanism 90 is assembled, there is a gap between each meshing gear pair (including the seventh gear 92311, the eighth gear 92313, the ninth gear 92314, and the tenth gear 92316 in the gear set 9231, and the fifth gear 921 and the sixth gear 922, respectively). At this time, by contracting the linear actuator 9236, the first gear connecting shaft 92312 and the second gear connecting shaft 92315 rotate relative to each other. The aforementioned planetary gears are respectively in close contact with the tooth surfaces of the fifth gear 921 and the sixth gear 922 near surface A, thereby eliminating the tooth backlash. When the gear set 923 with backlash elimination function is driven clockwise, the ninth gear 92314 and the tenth gear 92316 on the second gear connecting shaft 92315 are driven with the fifth gear 921 and the sixth gear 922 respectively without backlash; when driven in the reverse direction, the seventh gear 92311 and the eighth gear 92313 on the first gear shaft 92312 are driven with the fifth gear 921 and the sixth gear 922 respectively without backlash, ensuring the load sharing of each transmission gear. Thus, the decoupling mechanism 92 has the ability to achieve high-efficiency backlash-free transmission while eliminating the influence of the steering motor 81 on the rotation of the roller.

[0046] The drive gear set 93 includes: an eleventh gear 931, a twelfth gear 932, a thirteenth gear 933, a fourteenth gear 934, and a fifteenth gear 935. The eleventh gear 931 is fixedly connected to the rolling output shaft 924, maintaining synchronous rotation. The twelfth and thirteenth gears 932 and 933 are coaxially mounted on the first rotating shaft 60 and fixedly mounted on the first rotating shaft 60, maintaining synchronous rotation. The fourteenth gear 934 is coaxially mounted on the first fixed shaft 50 via bearings, and can rotate relative to the first fixed shaft 50. The fifteenth gear 935 is coaxially mounted on the first wheel shaft 40 via bearings, and can rotate relative to the first wheel shaft 40.

[0047] Among them, the eleventh gear 931 meshes with the twelfth gear 932, the twelfth gear 932 drives the first rotating shaft 60 to rotate, the first rotating shaft 60 drives the thirteenth gear 933 to rotate, the thirteenth gear 933 meshes with the fourteenth gear 934, driving the fourteenth gear 934 to rotate around the first fixed shaft 50, and the fourteenth gear 934 meshes with the fifteenth gear 935, driving the fifteenth gear 935 to rotate.

[0048] The differential gear set 94 includes: a differential gearbox 941, a sixteenth gear 942, a seventeenth gear 943, an eighteenth gear 944, and a nineteenth gear 945. The differential gearbox 941 is fixedly mounted on the fifteenth gear 935, and the differential gearbox 941 rotates synchronously with the fifteenth gear 935. The sixteenth gear 942 and the eighteenth gear 944 are coaxially fixedly mounted on the differential gearbox 941, and the sixteenth gear 942 and the eighteenth gear 944 can rotate around their central axis. The seventeenth gear 943 and the nineteenth gear 945 are installed between the sixteenth gear 942 and the eighteenth gear 944, and the seventeenth gear 943 and the nineteenth gear 945 are respectively... The sixteenth gear 942 and the eighteenth gear 944 mesh; the seventeenth gear 943 and the nineteenth gear 945 are coaxially mounted. The seventeenth gear 943 is fixedly mounted on one end of the first wheel axle 40, and the first roller 10 is fixedly mounted on the other end of the first wheel axle 40. The nineteenth gear 945 is fixedly mounted on one end of the second wheel axle 30, and the second roller 20 is fixedly mounted on the other end of the second wheel axle 30. The first wheel axle 40 and the second wheel axle 30 are mounted on the bogie 70 through bearings and can rotate relative to the bogie 70.

[0049] In this configuration, the differential gearbox 941 rotates synchronously with the fifteenth gear 935. When the decoupled active swivel caster travels in a straight line, the sixteenth gear 942 and the eighteenth gear 944 do not rotate around their own axes, while the seventeenth gear 943 and the nineteenth gear 945 rotate around their own axes at the same speed, thereby driving the first roller 10 and the second roller 20 to roll at the same speed. When the decoupled active swivel caster turns, the sixteenth gear 942 and the eighteenth gear 944 rotate around their own axes, causing the seventeenth gear 943 and the nineteenth gear 945 to rotate around their own axes at different speeds, thereby driving the first roller 10 and the second roller 20 to roll at different speeds.

[0050] The steering gear set 82 includes a first gear 821, a second gear 822, a third gear 823, and a fourth gear 824. The first gear 821 and the second gear 822 are coaxially fixedly mounted on the output shaft of the steering motor 81, and the steering motor 81 drives the first gear 821 and the second gear 822 to rotate synchronously. The third gear 823 is mounted on the base 100 through a bearing, and the third gear 823 is coaxially mounted with the second gear 822 and is fixedly connected to the second gear 822 to maintain synchronous rotation. The fourth gear 824 is mounted on the base 100 through a bearing, and the fourth gear 824 is coaxially mounted with the third gear 823.

[0051] Among them, the bogie 70 is fixedly installed below the fourth gear 824 and rotates synchronously;

[0052] The bogie 70 is connected to the base 100 via bearings, and the bogie 70 and the base 100 can rotate relative to each other;

[0053] There is a predetermined distance between the vertical diameter lines of the first roller 10 and the second roller 20 and the axis of the fourth gear 824;

[0054] The decoupled active omnidirectional wheel assembly also includes a drive reducer and a steering reducer. The drive reducer is mounted on the output shaft of the drive motor 91, and the steering reducer is mounted on the output shaft of the steering motor 81.

[0055] The motion analysis of the decoupled active omnidirectional wheel assembly is as follows:

[0056] Let the input speed of drive motor 91 be n. d The input speed of the steering motor 81 is n s The rotational speed transmitted from the drive motor 91 to the fifteenth gear 935 is n. dr The additional rotational speed n of the fifteenth gear 935 caused by steering sr The steering motor 81 transmits a rotational speed of n to the bogie 70 via the steering gear set 82. sk ;

[0057] The rotational speed of the i-th gear is n i The number of teeth is z i ;

[0058] The transmission ratio i between gear j and gear k jk for:

[0059] The transmission ratio i of the decoupling mechanism x for:

[0060] During actual operation, the rotational speed of bogie 70 is:

[0061]

[0062] The fifteenth gear's rotational speed n 15 for:

[0063] n 15 =n sr +n dr

[0064] The rotational speed transmitted from the drive motor 91 to the fifteenth gear 935 is n. dr for:

[0065]

[0066] The additional speed n of the fifteenth gear 935 caused by steering sr for:

[0067]

[0068] By summarizing the above equations, when the following conditions are met, the influence of the steering motor on the speed of the fifteenth gear can be eliminated, thereby eliminating the influence on the rolling of the roller and achieving the purpose of decoupling.

[0069]

[0070] That is, the decoupled active omnidirectional wheel assembly of the present invention should meet the above conditions.

[0071] like Figures 8 to 10 The omnidirectional mobile platform provided for this embodiment includes: a storage plate 110, a ball joint connection device 120, a spring 130, a base box (middle plate 140, through hole 150, base plate 160, lifting mechanism 170, casters) and three decoupled active omnidirectional wheel assemblies.

[0072] The casters and lifting mechanism 170 are fixedly connected to the base plate. The middle plate 140 is installed parallel to the base plate 160 at a fixed distance. The middle plate 140 has a through hole. The output shaft of the lifting mechanism 170 passes through the through hole 150 and is connected to the shelf 110 through the ball joint connection device 120. The shelf 110 is connected to the middle plate 140 through the spring 130.

[0073] A depth sensor 190 is installed on the outer side of each side of the base plate 160. It can detect the distance between the omnidirectional mobile platform and obstacles in the surrounding environment and obtain environmental information in advance. It can also obtain information on the surrounding terrain conditions, including the degree of potholes and slope angles, to provide information support for the path planning of the omnidirectional mobile platform and the angle adjustment of the placement platform.

[0074] An angle sensor 180 is installed below the center of gravity of the shelf 110, which can detect the angle between the shelf 110 and the horizontal plane, and can more accurately reflect the working status of the shelf 110.

[0075] The omnidirectional moving platform can raise or lower the position of the platform by adjusting the height of all lifting mechanisms.

[0076] The omnidirectional mobile platform can tilt the platform by adjusting the height of some of the lifting mechanisms.

[0077] The omnidirectional mobile platform can actively detect surrounding environmental information and determine the distance between itself and surrounding obstacles and the inclination angle of surrounding slopes based on the data returned by the depth sensor 190. Then, the lifting mechanism 170 actively adjusts the height and angle of the placement plate 110, so that the omnidirectional mobile platform can better adapt to changes in surrounding environmental obstacles and terrain, and improve the stability of the omnidirectional mobile platform during operation.

Claims

1. A decoupled active omnidirectional wheel assembly for precision drive, comprising a housing, a freely steerable wheel frame mounted below the housing, a first roller and a second roller located on both sides of the wheel frame, and a first wheel axle and a second wheel axle respectively driving the first roller and the second roller to rotate, characterized in that, The housing is equipped with a drive device that provides driving force to the first and second wheel axles and a steering device for controlling the steering of the wheel frame; The driving device includes a drive motor, a decoupling mechanism, a drive gear set, and a differential gear set. The driving force output by the drive motor is decoupled through the decoupling mechanism, and the decoupled driving force is output to the first axle and the second axle in conjunction with the drive gear set and the differential gear set. The steering device includes a steering motor, a steering gear set, and a steering mechanism that controls the rotation of the wheel frame. The rotational force output by the steering motor is output to the decoupling mechanism and the steering mechanism through the steering gear set. The decoupling mechanism decouples the rolling output derived when the rollers turn. The decoupling mechanism includes a fifth gear mounted on the output shaft of the drive motor, a sixth gear arranged coaxially opposite to the fifth gear, a backlash-free gear set arranged between the fifth and sixth gears for transmitting driving force, and a rolling output shaft fixedly connected to the backlash-free gear set. The rolling output shaft is mounted coaxially with the sixth gear. The backlash-free gear set includes one or more gear sets, a force sensor for acquiring the meshing force between the gears, and a linear actuator for adjusting the meshing force between the gears. The gear set includes a first gear connecting shaft, a seventh gear and an eighth gear fixed at both ends of the first gear connecting shaft, a second gear connecting shaft, and a ninth gear and a tenth gear fixed at both ends of the second gear connecting shaft. The first gear connecting shaft and the second gear connecting shaft are arranged alternately. One end of the force sensor is fixed to the first gear connecting shaft, and the other end is fixed to the stator of the linear actuator. The mover of the linear actuator is fixed to the second gear connecting shaft.

2. The decoupled active omnidirectional wheel assembly for precision drive according to claim 1, characterized in that, The steering gear set includes a first gear, a second gear, a third gear, and a fourth gear. The first gear and the second gear are coaxially fixedly mounted on the output shaft of the steering motor. The third gear and the fourth gear are coaxially mounted on the inner side wall of the housing. The third gear meshes externally with the first gear and rotates synchronously. The fourth gear meshes externally with the second gear and rotates synchronously. The wheel frame is fixedly mounted below the fourth gear.

3. The decoupled active omnidirectional wheel assembly for precision drive according to claim 1, characterized in that, The drive gear set includes an eleventh gear, a twelfth gear, a thirteenth gear, a fourteenth gear, and a fifteenth gear. The eleventh gear is fixed to the rolling output shaft and rotates synchronously. The twelfth and thirteenth gears are coaxially mounted with the first rotating shaft of the steering mechanism and are respectively fixed on the first rotating shaft of the steering mechanism and rotate synchronously. The fourteenth gear is fixed on the inner side wall of the wheel frame and rotates relative to it. The fifteenth gear is mounted on the wheel axle and rotates relative to it.

4. The decoupled active omnidirectional wheel assembly for precision drive according to claim 1, characterized in that, The differential gear set includes: a differential gearbox, a sixteenth gear, a seventeenth gear, an eighteenth gear, and a nineteenth gear. The differential gearbox is fixed to the tooth side surface of the fifteenth gear to maintain synchronous rotation. The sixteenth and eighteenth gears are arranged coaxially on the side of the differential gearbox to ensure rotation. The seventeenth and nineteenth gears are coaxially fixed to one end of the shaft wheel. The seventeenth gear meshes with the sixteenth and eighteenth gears respectively, and the nineteenth gear meshes with the sixteenth and eighteenth gears respectively.

5. The decoupled active omnidirectional wheel assembly for precision drive according to claim 1, characterized in that, The vertical diameter line of the roller is spaced at a predetermined distance from the axis of the output shaft of the drive motor.

6. An omnidirectional mobile platform, characterized in that, The device includes a storage platform and at least three decoupled active caster wheel assemblies as described in any one of claims 1 to 5. The storage platform includes a storage plate, a base box, and a lifting mechanism for changing the height of the storage plate. A plurality of springs for cushioning are provided between the storage plate and the top of the base box. The decoupled active caster wheel assemblies are arranged inside the base box.

7. An omnidirectional mobile platform according to claim 6, characterized in that, The base plate box is also equipped with a depth sensor and a tilt sensor for feedback of movement position.

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