Omnidirectional mobile chassis structure and control method of ordinary wheel drive without steering rudder

Abstract

An omnidirectional mobile chassis structure and control method for a general wheel drive without a steering servo. The chassis structure includes a chassis frame assembly, four sets of wheel systems, two sets of gear transmission assemblies, and two sets of corner detection assemblies. The four sets of wheel systems are distributed in two diagonals, with one set of gear transmission assembly and one set of corner detection assembly configured on each diagonal. Each wheel is equipped with a motor, and no steering servo is provided. The control method is as follows: When performing omnidirectional translation, an omnidirectional translation calculation formula is established, the wheel deflection angle and the desired translation speed are input, and according to the calculation result, four motors are controlled to drive the wheels to rotate to achieve omnidirectional translation. When rotating in place, an in-place rotation calculation formula is established. The two wheels on the first diagonal rotate clockwise to the limit position, and the other diagonal rotates counterclockwise synchronously. The wheels on the two diagonals are divided into a set of driving wheels and a set of driven wheels. The desired angular velocity of rotation in place is input, and according to the calculation result, the motors are controlled to drive the wheels to rotate to achieve rotation in place.

Description

Technical Field

[0001] The present invention belongs to the technical field of omnidirectional mobile robots, and particularly relates to an omnidirectional mobile chassis structure and control method without a steering servo driven by ordinary wheels. Background Art

[0002] Omnidirectional mobile robots can achieve omnidirectional movement in a narrow space, enabling them to have a wider range of application scenarios. Compared with traditional mobile robots, omnidirectional mobile robots have three degrees of freedom in the global coordinate system, namely translation in any direction and rotation around the vertical axis. They can also maintain their own posture during omnidirectional movement and can achieve in-situ rotation, that is, zero-radius rotation, solving the drawbacks of traditional mobile robots.

[0003] Currently, omnidirectional mobile robots can be roughly divided into two categories according to different driving methods. The first category is to achieve omnidirectional movement by changing the wheel system structure, that is, by applying Mecanum wheels, omnidirectional wheels, spherical wheels, etc.; the second category is to achieve omnidirectional movement by independent driving, that is, by equipping a wheel with two motors, one motor is responsible for walking, and the other motor serves as a steering servo to be responsible for steering.

[0004] However, when an omnidirectional mobile robot adopts the first driving method, since special structure wheels such as Mecanum wheels, omnidirectional wheels, and spherical wheels need to be applied, compared with ordinary wheels, these special structure wheels have higher requirements for environmental conditions and are prone to wheel damage in a harsh environment. When an omnidirectional mobile robot adopts the second driving method, since each wheel needs to be equipped with a walking motor and a steering servo, and the two need to cooperate to achieve omnidirectional movement, too many motors will not only increase the structural complexity and energy consumption of the robot system, but also lead to a larger occupied space. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides an omnidirectional mobile chassis structure and control method without a steering servo driven by ordinary wheels. Each wheel only needs to be equipped with one motor, and without configuring a steering servo, the omnidirectional movement of the robot can be achieved. At the same time, it has the advantage of small occupied space, and only ordinary wheels are used for the wheels, reducing the requirements of the wheels for environmental conditions, with a simpler structure and effectively reducing the energy consumption of the robot system.

[0006] In order to achieve the above-mentioned objectives, the present invention adopts the following technical solutions: a common wheel-driven omnidirectional mobile chassis structure without a steering servo, comprising a chassis frame assembly, a first wheel train assembly, a second wheel train assembly, a third wheel train assembly, a fourth wheel train assembly, a first gear transmission assembly, a second gear transmission assembly, a first rotation angle detection assembly and a second rotation angle detection assembly; the first wheel train assembly, the second wheel train assembly, the third wheel train assembly and the fourth wheel train assembly are evenly arranged on the chassis frame assembly, the first wheel train assembly and the second wheel train assembly are diagonally distributed, and the third wheel train assembly and the fourth wheel train assembly are diagonally distributed; the first gear transmission assembly is arranged on the chassis frame assembly, and the first wheel train assembly is connected to the second wheel train assembly through the first gear transmission assembly; the second gear transmission assembly is arranged on the chassis frame assembly, and the third wheel train assembly is connected to the fourth wheel train assembly through the second gear transmission assembly; the first rotation angle detection assembly is arranged between the chassis frame assembly and the first gear transmission assembly; the second rotation angle detection assembly is arranged between the chassis frame assembly and the second gear transmission assembly.

[0007] The chassis frame assembly includes an upper cover plate, a middle upper support plate, an intermediate support plate, a middle lower support plate and a lower cover plate; the upper cover plate, the middle upper support plate, the intermediate support plate, the middle lower support plate and the lower cover plate are arranged sequentially and in parallel from top to bottom, and gaps are left between the upper cover plate and the middle upper support plate, between the middle upper support plate and the intermediate support plate, between the intermediate support plate and the middle lower support plate, and between the middle lower support plate and the lower cover plate; the upper cover plate, the middle upper support plate, the intermediate support plate, the middle lower support plate and the lower cover plate are fixedly connected together; a main body stud is installed in the center of the upper cover plate, the middle upper support plate, the intermediate support plate, the middle lower support plate and the lower cover plate, the top end of the main body stud is fixedly connected to the upper cover plate, and the bottom end of the main body stud is fixedly connected to the lower cover plate.

[0008] The first wheel train assembly, the second wheel train assembly, the third wheel train assembly and the fourth wheel train assembly have the same structure and all include ordinary wheels, drive motors, lower legs, upper legs, bearing seats and shock-absorbing mechanisms; the upper end of the upper leg of the first wheel train assembly is connected to one end of the middle and lower support plates through the bearing seat; the upper end of the upper leg of the second wheel train assembly is connected to the other end of the middle and lower support plates through the bearing seat; the upper end of the upper leg of the third wheel train assembly is connected to one end of the middle support plate through the bearing seat; the upper end of the upper leg of the fourth wheel train assembly is connected to the other end of the middle support plate through the bearing seat; the lower end of the upper leg is connected to the upper end of the lower leg through a shock-absorbing mechanism; the drive motor is horizontally fixed at the lower end of the lower leg; the ordinary wheel is coaxially fixed on the motor shaft of the drive motor; the drive motor is electrically connected to a PID controller.

[0009] The shock absorption mechanism includes a shock absorption spring, a guiding slide rail and a guiding slider; the shock absorption spring is arranged obliquely, one end of the shock absorption spring is fixedly connected to the upper support leg, and the other end of the shock absorption spring is fixedly connected to the lower support leg; the guiding slide rail is vertically and fixedly installed on the lower support leg, the guiding slider is arranged on the guiding slide rail, and the guiding slider has a vertical movement freedom degree on the guiding slide rail; the upper support leg is fixedly connected to the guiding slider.

[0010] The first gear transmission assembly and the second gear transmission assembly have the same structure, and both include a first driving gear, a first intermediate gear, a driven gear, a second intermediate gear and a second driving gear; the first driving gear of the first gear transmission assembly is fixedly connected to the upper end of the upper support leg of the first gear train assembly; the second driving gear of the first gear transmission assembly is fixedly connected to the upper end of the upper support leg of the second gear train assembly; the first driving gear of the second gear transmission assembly is fixedly connected to the upper end of the upper support leg of the third gear train assembly; the second driving gear of the second gear transmission assembly is fixedly connected to the upper end of the upper support leg of the fourth gear train assembly; the first driving gear meshes with the first intermediate gear, the first intermediate gear meshes with the driven gear, the driven gear meshes with the second intermediate gear, and the second intermediate gear meshes with the second driving gear; the first intermediate gear and the second intermediate gear of the first gear transmission assembly are both rotatably connected to the middle lower support plate; the first intermediate gear and the second intermediate gear of the second gear transmission assembly are both rotatably connected to the middle support plate; the driven gear of the first gear transmission assembly is coaxially installed on the main body stud between the middle lower support plate and the middle support plate through a bearing; the driven gear of the second gear transmission assembly is coaxially installed on the main body stud between the middle support plate and the middle upper support plate through a bearing.

[0011] The first rotation angle detection assembly and the second rotation angle detection assembly have the same structure, and both include a magnetic encoder, an encoder bracket, a magnet and a magnet bracket; the magnetic encoder is fixedly installed on the encoder bracket, the magnet is fixedly installed on the magnet bracket, and the magnet is located directly below the magnetic encoder and is arranged oppositely; the encoder bracket of the first rotation angle detection assembly is fixedly installed on the middle support plate, and the magnet bracket of the first rotation angle detection assembly is fixedly installed on the first driving gear or the second driving gear of the first gear transmission assembly; the encoder bracket of the second rotation angle detection assembly is fixedly installed on the middle upper support plate, and the magnet bracket of the second rotation angle detection assembly is fixedly installed on the first driving gear or the second driving gear of the second gear transmission assembly; the magnet and the first driving gear or the second driving gear are coaxially distributed.

[0012] A first corner limiting mechanism is arranged between the driven gear of the first gear transmission assembly and the middle-lower support plate; a second corner limiting mechanism is arranged between the driven gear of the second gear transmission assembly and the middle-upper support plate; the first corner limiting mechanism and the second corner limiting mechanism have the same structure, and both include a rocker, a swing rod, a stop pin, a limit stop block, a stop block position adjustment chute and a stop block positioning screw; one end of the rocker is connected to the main body stud through a bearing, the rod body of the rocker is fixedly connected to the driven gear, and the other end of the rocker is a free end; the stop block position adjustment chute of the first gear transmission assembly is arranged on the middle-lower support plate; the stop block position adjustment chute of the second gear transmission assembly is arranged on the middle-upper support plate; two limit stop blocks are installed in the stop block position adjustment chute, and a stop block positioning screw is installed between the stop block position adjustment chute and the limit stop block; the middle of the swing rod of the first gear transmission assembly is hinged to the middle-lower support plate; the middle of the swing rod of the second gear transmission assembly is hinged to the middle-upper support plate; one end of the swing rod is located between the two limit stop blocks, and a stop pin is installed at the other end of the swing rod, and the stop pin is matched with the free end of the rocker.

[0013] A first installation position fine-tuning mechanism is arranged between the first intermediate gear of the first gear transmission assembly and the middle-lower support plate; a second installation position fine-tuning mechanism is arranged between the second intermediate gear of the first gear transmission assembly and the middle-lower support plate; a third installation position fine-tuning mechanism is arranged between the first intermediate gear of the second gear transmission assembly and the middle support plate; a fourth installation position fine-tuning mechanism is arranged between the second intermediate gear of the second gear transmission assembly and the middle support plate; the first installation position fine-tuning mechanism, the second installation position fine-tuning mechanism, the third installation position fine-tuning mechanism and the fourth installation position fine-tuning mechanism have the same structure, and all include an intermediate gear installation bolt, a gear position adjustment plate and an adjustment plate positioning screw; one end of the intermediate gear installation bolt is rotatably connected to the first intermediate gear or the second intermediate gear through a bearing, and the other end of the intermediate gear installation bolt is fixedly connected to the gear position adjustment plate; a waist-shaped hole is opened on the gear position adjustment plate, and the adjustment plate positioning screw passes through the waist-shaped hole and is connected to the middle-lower support plate or the middle support plate; an adjustment plate limit chute is opened on the middle-lower support plate or the middle support plate, and the gear position adjustment plate is located in the adjustment plate limit chute.

[0014] A control method for an omnidirectional mobile chassis structure of a general wheel drive non-steering servo. When the chassis needs to translate omnidirectionally, first establish an omnidirectional translation calculation formula, which is as follows:

[0015]

[0016] Where, ω1 is the rotational angular velocity of the left front wheel, ω2 is the rotational angular velocity of the right front wheel, ω3 is the rotational angular velocity of the right rear wheel, ω4 is the rotational angular velocity of the left rear wheel, r is the wheel radius, b is the horizontal distance between the wheel center and the vertical rotation center of the wheel, v is the desired translational velocity, θ t is the desired wheel deflection angle, θ t-1 is the wheel deflection angle at the previous moment, and t is the time;

[0017] After that, according to the established omnidirectional translation calculation formula, the desired wheel deflection angle θ t and the desired translational velocity v are input into the PID controller. Through the automatic calculation of the omnidirectional translation calculation formula, the rotational angular velocities required for the four wheels can be obtained. Then, the four corresponding wheels are respectively driven by four drive motors to rotate at the calculated rotational angular velocities, realizing the omnidirectional translation of the robot. And during the omnidirectional translation of the robot, the desired wheel deflection angle θ t is detected and fed back by the magnetic encoder.

[0018] A control method for an omnidirectional mobile chassis structure with ordinary wheel drive and no steering servo. When the chassis needs to rotate in place, first establish the in-place rotation calculation formula as follows:

[0019]

[0020] Where, ω i is the rotational angular velocity of the wheel, and i = 1, 2, 3, 4, d is the horizontal distance between the geometric center of the chassis and the wheel center, r is the wheel radius, and ω is the desired rotational angular velocity;

[0021] After that, control the two wheels on the diagonal line of the left front wheel and the right rear wheel to rotate clockwise to the extreme position, and at the same time control the two wheels on the diagonal line of the right front wheel and the left rear wheel to rotate counterclockwise to the extreme position. The rotation angle of the wheels is detected and fed back by the magnetic encoder; after all four wheels rotate to the extreme position, if the chassis needs to rotate clockwise in place, the left front wheel and the right rear wheel are used as the driving wheels, and the right front wheel and the left rear wheel are used as the driven wheels; if the chassis needs to rotate counterclockwise in place, the right front wheel and the left rear wheel are used as the driving wheels, and the left front wheel and the right rear wheel are used as the driven wheels;

[0022] Subsequently, according to the established in-place rotation calculation formula, the desired rotational angular velocity ω is input into the PID controller. Through the automatic calculation of the in-place rotation calculation formula, the required rotational angular velocity ω i can be obtained. Then, the drive motor drives the corresponding wheel to rotate at the calculated rotational angular velocity, realizing the in-place rotation of the robot.

[0023] Advantages of the present invention:

[0024] The omnidirectional mobile chassis structure and control method of a general wheel-driven steeringless servo of the present invention. Each wheel only needs to be equipped with one motor, without configuring a steering servo, and can realize the omnidirectional movement of the robot. At the same time, it has the advantage of small occupied space, and only ordinary wheels are used for the wheels, reducing the requirements of the wheels for environmental conditions, with a simpler structure, and can effectively reduce the energy consumption of the robot system. Description of the Drawings

[0025] Figure 1 It is a schematic diagram (viewpoint one) of the omnidirectional mobile chassis structure of the general wheel-driven steeringless servo of the present invention;

[0026] Figure 2 It is a schematic diagram (viewpoint two) of the omnidirectional mobile chassis structure of the general wheel-driven steeringless servo of the present invention;

[0027] Figure 3 It is a schematic diagram (viewpoint three) of the omnidirectional mobile chassis structure of the general wheel-driven steeringless servo of the present invention (when the wheels rotate to the extreme position, the upper cover plate and the middle upper support plate are not shown);

[0028] In the figure, 1 - upper cover plate, 2 - middle upper support plate, 3 - middle support plate, 4 - middle lower support plate, 5 - lower cover plate, 6 - main body stud, 7 - general wheel, 8 - drive motor, 9 - lower leg, 10 - upper leg, 11 - bearing seat, 12 - shock-absorbing spring, 13 - guiding slide rail, 14 - guiding slider, 15 - first driving gear, 16 - first intermediate gear, 17 - driven gear, 18 - second intermediate gear, 19 - second driving gear, 20 - magnetic encoder, 21 - encoder bracket, 22 - magnet, 23 - magnet bracket, 24 - rocker, 25 - swing rod, 26 - retaining pin, 27 - limit stop block, 28 - stop block position adjustment chute, 29 - stop block positioning screw, 30 - intermediate gear mounting bolt, 31 - gear position adjustment plate, 32 - adjustment plate positioning screw, 33 - kidney-shaped hole, 34 - adjustment plate limit chute. Detailed Embodiment

[0029] The following further elaborates on the present invention in detail in conjunction with the drawings and specific embodiments.

[0030] As Figures 1 to 3As shown, a common wheel-driven omnidirectional mobile chassis structure without steering servo comprises a chassis frame assembly, a first wheel train assembly, a second wheel train assembly, a third wheel train assembly, a fourth wheel train assembly, a first gear transmission assembly, a second gear transmission assembly, a first rotation angle detection assembly and a second rotation angle detection assembly; the first wheel train assembly, the second wheel train assembly, the third wheel train assembly and the fourth wheel train assembly are evenly arranged on the chassis frame assembly, the first wheel train assembly and the second wheel train assembly are diagonally distributed, and the third wheel train assembly and the fourth wheel train assembly are diagonally distributed; the first gear transmission assembly is arranged on the chassis frame assembly, and the first wheel train assembly is connected to the second wheel train assembly through the first gear transmission assembly; the second gear transmission assembly is arranged on the chassis frame assembly, and the third wheel train assembly is connected to the fourth wheel train assembly through the second gear transmission assembly; the first rotation angle detection assembly is arranged between the chassis frame assembly and the first gear transmission assembly; the second rotation angle detection assembly is arranged between the chassis frame assembly and the second gear transmission assembly.

[0031] The chassis frame assembly includes an upper cover plate 1, a middle upper support plate 2, a middle support plate 3, a middle lower support plate 4 and a lower cover plate 5; the upper cover plate 1, the middle upper support plate 2, the middle support plate 3, the middle lower support plate 4 and the lower cover plate 5 are distributed sequentially and in parallel from top to bottom, and there are gaps between the upper cover plate 1 and the middle upper support plate 2, between the middle upper support plate 2 and the middle support plate 3, between the middle support plate 3 and the middle lower support plate 4, and between the middle lower support plate 4 and the lower cover plate 5; the upper cover plate 1, the middle upper support plate 2, the middle support plate 3, the middle lower support plate 4 and the lower cover plate 5 are fixedly connected together; a main body stud 6 is installed in the center of the upper cover plate 1, the middle upper support plate 2, the middle support plate 3, the middle lower support plate 4 and the lower cover plate 5, the top end of the main body stud 6 is fixedly connected to the upper cover plate 1, and the bottom end of the main body stud 6 is fixedly connected to the lower cover plate 5.

[0032] The first wheel train assembly, the second wheel train assembly, the third wheel train assembly and the fourth wheel train assembly have the same structure and all include an ordinary wheel 7, a drive motor 8, a lower support leg 9, an upper support leg 10, a bearing seat 11 and a shock-absorbing mechanism; the upper end of the upper support leg 10 of the first wheel train assembly is connected to one end of the middle and lower support plate 4 through the bearing seat 11; the upper end of the upper support leg 10 of the second wheel train assembly is connected to the other end of the middle and lower support plate 4 through the bearing seat 11; the upper end of the upper support leg 10 of the third wheel train assembly is connected to one end of the middle support plate 3 through the bearing seat 11; the upper end of the upper support leg 10 of the fourth wheel train assembly is connected to the other end of the middle support plate 3 through the bearing seat 11; the lower end of the upper support leg 10 is connected to the upper end of the lower support leg 9 through a shock-absorbing mechanism; the drive motor 8 is horizontally fixed at the lower end of the lower support leg 9; the ordinary wheel 7 is coaxially fixed on the motor shaft of the drive motor 8; the drive motor 8 is electrically connected to the PID controller.

[0033] The shock absorption mechanism includes a shock absorption spring 12, a guiding slide rail 13 and a guiding slider 14; the shock absorption spring 12 is inclined, one end of the shock absorption spring 12 is fixedly connected to the upper leg 10, and the other end of the shock absorption spring 12 is fixedly connected to the lower leg 9; the guiding slide rail 13 is vertically and fixedly installed on the lower leg 9, the guiding slider 14 is arranged on the guiding slide rail 13, and the guiding slider 14 has a vertical movement degree of freedom on the guiding slide rail 13; the upper leg 10 is fixedly connected to the guiding slider 14.

[0034] The first gear transmission assembly and the second gear transmission assembly have the same structure, and both include a first driving gear 15, a first intermediate gear 16, a driven gear 17, a second intermediate gear 18 and a second driving gear 19; the first driving gear 15 of the first gear transmission assembly is fixedly connected to the upper end of the upper leg 10 of the first gear train assembly; the second driving gear 19 of the first gear transmission assembly is fixedly connected to the upper end of the upper leg 10 of the second gear train assembly; the first driving gear 15 of the second gear transmission assembly is fixedly connected to the upper end of the upper leg 10 of the third gear train assembly; the second driving gear 19 of the second gear transmission assembly is fixedly connected to the upper end of the upper leg 10 of the fourth gear train assembly; the first driving gear 15 meshes with the first intermediate gear 16, the first intermediate gear 16 meshes with the driven gear 17, the driven gear 17 meshes with the second intermediate gear 18, and the second intermediate gear 18 meshes with the second driving gear 19; the first intermediate gear 16 and the second intermediate gear 18 of the first gear transmission assembly are both rotatably connected to the middle lower support plate 4; the first intermediate gear 16 and the second intermediate gear 18 of the second gear transmission assembly are both rotatably connected to the middle support plate 3; the driven gear 17 of the first gear transmission assembly is coaxially installed on the main body stud 6 between the middle lower support plate 4 and the middle support plate 3 through a bearing; the driven gear 17 of the second gear transmission assembly is coaxially installed on the main body stud 6 between the middle support plate 3 and the middle upper support plate 2 through a bearing. Specifically, the number of the first intermediate gear 16 and the second intermediate gear 18 can be adjusted to meet the change of the size of the omnidirectional mobile robot.

[0035] The first corner detection component and the second corner detection component have the same structure, and both include a magnetic encoder 20, an encoder bracket 21, a magnet 22, and a magnet bracket 23. The magnetic encoder 20 is fixedly installed on the encoder bracket 21, and the magnet 22 is fixedly installed on the magnet bracket 23. The magnet 22 is located directly below the magnetic encoder 20 and is arranged opposite to it. The encoder bracket 21 of the first corner detection component is fixedly installed on the middle support plate 3, and the magnet bracket 23 of the first corner detection component is fixedly installed on the first driving gear 15 or the second driving gear 19 of the first gear transmission component. The encoder bracket 21 of the second corner detection component is fixedly installed on the middle upper support plate 2, and the magnet bracket 23 of the second corner detection component is fixedly installed on the first driving gear 15 or the second driving gear 19 of the second gear transmission component. The magnet 22 is coaxially distributed with the first driving gear 15 or the second driving gear 19.

[0036] A first corner limit mechanism is provided between the driven gear 17 of the first gear transmission component and the middle lower support plate 4. A second corner limit mechanism is provided between the driven gear 17 of the second gear transmission component and the middle upper support plate 2. The first corner limit mechanism and the second corner limit mechanism have the same structure, and both include a rocker 24, a swing rod 25, a stop pin 26, a limit stop block 27, a stop block position adjustment chute 28, and a stop block positioning screw 29. One end of the rocker 24 is connected to the main body stud 6 through a bearing. The rod body of the rocker 24 is fixedly connected to the driven gear 17, and the other end of the rocker 24 is a free end. The stop block position adjustment chute 28 of the first gear transmission component is arranged on the middle lower support plate 4. The stop block position adjustment chute 28 of the second gear transmission component is arranged on the middle upper support plate 2. Two limit stop blocks 27 are installed in the stop block position adjustment chute 28, and a stop block positioning screw 29 is installed between the stop block position adjustment chute 28 and the limit stop block 27. The middle part of the swing rod 25 of the first gear transmission component is hinged on the middle lower support plate 4. The middle part of the swing rod 25 of the second gear transmission component is hinged on the middle upper support plate 2. One end of the swing rod 25 is located between the two limit stop blocks 27, and a stop pin 26 is installed at the other end of the swing rod 25. The stop pin 26 cooperates with the free end of the rocker 24. Specifically, through a 360° rotation of the driven gear 17, the rotation limit positions in both forward and reverse directions of the wheel can be achieved.

[0037] A first installation position fine-tuning mechanism is provided between the first intermediate gear 16 of the first gear transmission assembly and the middle lower support plate 4; a second installation position fine-tuning mechanism is provided between the second intermediate gear 18 of the first gear transmission assembly and the middle lower support plate 4; a third installation position fine-tuning mechanism is provided between the first intermediate gear 16 of the second gear transmission assembly and the middle support plate 3; a fourth installation position fine-tuning mechanism is provided between the second intermediate gear 18 of the second gear transmission assembly and the middle support plate 3; the first installation position fine-tuning mechanism, the second installation position fine-tuning mechanism, the third installation position fine-tuning mechanism and the fourth installation position fine-tuning mechanism have the same structure, and each includes an intermediate gear mounting bolt 30, a gear position adjustment plate 31 and an adjustment plate positioning screw 32; one end of the intermediate gear mounting bolt 30 is rotatably connected to the first intermediate gear 16 or the second intermediate gear 18 through a bearing, and the other end of the intermediate gear mounting bolt 30 is fixedly connected to the gear position adjustment plate 31; a waist-shaped hole 33 is formed in the gear position adjustment plate 31, and the adjustment plate positioning screw 32 passes through the waist-shaped hole 33 and is connected to the middle lower support plate 4 or the middle support plate 3; an adjustment plate limiting chute 34 is formed in the middle lower support plate 4 or the middle support plate 3, and the gear position adjustment plate 31 is located in the adjustment plate limiting chute 34.

[0038] A control method for an omnidirectional mobile chassis structure of a common wheel-driven non-steering servo. When the chassis needs to perform omnidirectional translation, first establish an omnidirectional translation calculation formula as follows:

[0039]

[0040] In the formula, ω1 is the rotational angular velocity of the left front wheel, ω2 is the rotational angular velocity of the right front wheel, ω3 is the rotational angular velocity of the right rear wheel, ω4 is the rotational angular velocity of the left rear wheel, r is the wheel radius, b is the horizontal distance between the wheel center and the vertical rotation center of the wheel, v is the desired translation speed, θ t is the desired wheel deflection angle, θ t-1 is the wheel deflection angle at the previous moment, and t is the time;

[0041] After that, according to the established omnidirectional translation calculation formula, input the desired wheel deflection angle θ t and the desired translation speed v into the PID controller. After automatic calculation of the omnidirectional translation calculation formula, the rotational angular velocities required for the four wheels can be obtained. Then, the four driving motors respectively drive the corresponding four wheels to rotate at the calculated rotational angular velocities, realizing the omnidirectional translation of the robot. And during the omnidirectional translation of the robot, the desired wheel deflection angle θ t is detected and fed back by the magnetic encoder 20.

[0042] Specifically, when a linear movement is required, the desired wheel deflection angle θt is 0, and only the desired translational speed v needs to be input; when movement in a certain direction is required, first input the desired wheel deflection angle θ t , and then input the desired translational speed v; when steering and movement need to be carried out simultaneously, input the desired wheel deflection angle θ t and the desired translational speed v at the same time.

[0043] A control method for an omnidirectional mobile chassis structure of a common wheel drive without a steering servo. When the chassis needs to rotate in place, first establish a rotation-in-place calculation formula as follows:

[0044]

[0045] In the formula, ω i is the wheel rotation angular velocity, and i = 1, 2, 3, 4, d is the horizontal distance between the geometric center of the chassis and the wheel center, r is the wheel radius, and ω is the desired rotation angular velocity;

[0046] After that, control the two wheels on the diagonal line of the left front wheel and the right rear wheel to rotate clockwise to the limit position, and at the same time control the two wheels on the diagonal line of the right front wheel and the left rear wheel to rotate counterclockwise to the limit position. The rotation angle of the wheels is detected and fed back by the magnetic encoder 20; after all four wheels rotate to the limit position, if the chassis needs to rotate clockwise in place, the left front wheel and the right rear wheel are used as the driving wheels, and the right front wheel and the left rear wheel are used as the driven wheels; if the chassis needs to rotate counterclockwise in place, the right front wheel and the left rear wheel are used as the driving wheels, and the left front wheel and the right rear wheel are used as the driven wheels;

[0047] Subsequently, according to the established rotation-in-place calculation formula, input the desired rotation angular velocity ω into the PID controller. After automatically calculating the rotation-in-place calculation formula, the required wheel rotation angular velocity ω i will be obtained, and then the corresponding wheels will be driven by the drive motor 8 to rotate at the calculated rotation angular velocity, realizing the rotation of the robot in place.

[0048] Specifically, when the chassis needs to rotate in place, the torques generated during the rotation of the left front wheel and the right rear wheel are equal in magnitude and opposite in direction to the torques generated during the rotation of the right front wheel and the left rear wheel. Therefore, when the wheels rotate around the vertical axis, each support plate and cover plate in the chassis frame assembly remain stationary relative to the ground.

[0049] During the rotation of the wheel around the vertical axis, the first driving gear 15 and the second driving gear 19 will be driven to rotate synchronously first, and then the driven gear 17 will be driven to rotate jointly by the first intermediate gear 16 and the second intermediate gear 18. The rotating driven gear 17 will further drive the rocker 24 to rotate. When the free end of the rocker 24 contacts the stop pin 26, the swing rod 25 will be driven to rotate until the other end of the swing rod 25 contacts the limit stop 27. At this time, the wheel will rotate to the extreme position and cannot continue to rotate.

[0050] The solutions in the embodiments are not intended to limit the patent protection scope of the present invention. Any equivalent implementation or modification without departing from the present invention is included in the patent scope of this case.

Claims

1. An omnidirectional mobile chassis structure with a common wheel drive and no steering servo, characterized in that: It includes a chassis frame assembly, a first wheel set assembly, a second wheel set assembly, a third wheel set assembly, a fourth wheel set assembly, a first gear transmission assembly, a second gear transmission assembly, a first rotation angle detection assembly and a second rotation angle detection assembly; the first wheel set assembly, the second wheel set assembly, the third wheel set assembly and the fourth wheel set assembly are evenly arranged on the chassis frame assembly, the first wheel set assembly and the second wheel set assembly are diagonally distributed, and the third wheel set assembly and the fourth wheel set assembly are diagonally distributed; the first gear transmission assembly is arranged on the chassis frame assembly, and the first wheel set assembly is drivingly connected to the second wheel set assembly through the first gear transmission assembly; the second gear transmission assembly is arranged on the chassis frame assembly, and the third wheel set assembly is drivingly connected to the fourth wheel set assembly through the second gear transmission assembly; the first rotation angle detection assembly is arranged between the chassis frame assembly and the first gear transmission assembly; the second rotation angle detection assembly is arranged between the chassis frame assembly and the second gear transmission assembly; The chassis frame assembly includes an upper cover plate, a middle upper support plate, a middle support plate, a middle lower support plate and a lower cover plate; the upper cover plate, the middle upper support plate, the middle support plate, the middle lower support plate and the lower cover plate are sequentially and parallelly distributed from top to bottom; The first wheel set assembly, the second wheel set assembly, the third wheel set assembly and the fourth wheel set assembly have the same structure and each includes a common wheel, a driving motor, a lower leg, an upper leg, a bearing seat and a shock absorption mechanism; the upper end of the upper leg of the first wheel set assembly is connected to one end of the middle lower support plate through the bearing seat; the upper end of the upper leg of the second wheel set assembly is connected to the other end of the middle lower support plate through the bearing seat; the upper end of the upper leg of the third wheel set assembly is connected to one end of the middle support plate through the bearing seat; the upper end of the upper leg of the fourth wheel set assembly is connected to the other end of the middle support plate through the bearing seat; the lower end of the upper leg is connected to the upper end of the lower leg through the shock absorption mechanism; the driving motor is horizontally and fixedly installed at the lower end of the lower leg; the common wheel is coaxially and fixedly installed on the motor shaft of the driving motor; the driving motor is electrically connected to the PID controller; The shock absorption mechanism includes a shock absorption spring, a guiding slide rail and a guiding slider; the shock absorption spring is obliquely arranged, one end of the shock absorption spring is fixedly connected to the upper leg, and the other end of the shock absorption spring is fixedly connected to the lower leg; the guiding slide rail is vertically and fixedly installed on the lower leg, the guiding slider is arranged on the guiding slide rail, and the guiding slider has a vertical movement freedom on the guiding slide rail; the upper leg is fixedly connected to the guiding slider; The first gear transmission assembly and the second gear transmission assembly have the same structure, and both include a first driving gear, a first intermediate gear, a driven gear, a second intermediate gear and a second driving gear; the first driving gear of the first gear transmission assembly is fixedly connected to the upper end of the upper leg of the first gear train assembly; the second driving gear of the first gear transmission assembly is fixedly connected to the upper end of the upper leg of the second gear train assembly; the first driving gear of the second gear transmission assembly is fixedly connected to the upper end of the upper leg of the third gear train assembly; the second driving gear of the second gear transmission assembly is fixedly connected to the upper end of the upper leg of the fourth gear train assembly; the first driving gear meshes with the first intermediate gear, the first intermediate gear meshes with the driven gear, the driven gear meshes with the second intermediate gear, and the second intermediate gear meshes with the second driving gear; the first intermediate gear and the second intermediate gear of the first gear transmission assembly are both rotatably connected to the middle and lower support plates; the first intermediate gear and the second intermediate gear of the second gear transmission assembly are both rotatably connected to the middle support plate; the driven gear of the first gear transmission assembly is coaxially installed on the main body stud between the middle and lower support plates and the middle support plate through a bearing; the driven gear of the second gear transmission assembly is coaxially installed on the main body stud between the middle support plate and the upper and middle support plates through a bearing.

2. The omnidirectional mobile chassis structure of a general wheel drive without a steering servo according to claim 1, characterized in that: There are gaps between the upper cover plate and the upper and middle support plates, between the upper and middle support plates and the middle support plate, between the middle support plate and the middle and lower support plates, and between the middle and lower support plates and the lower cover plate; the upper cover plate, the upper and middle support plates, the middle support plate, the middle and lower support plates and the lower cover plate are fixedly connected together; a main body stud is inserted through the centers of the upper cover plate, the upper and middle support plates, the middle support plate, the middle and lower support plates and the lower cover plate, and the top of the main body stud is fixedly connected to the upper cover plate, and the bottom of the main body stud is fixedly connected to the lower cover plate.

3. The omnidirectional mobile chassis structure of a general wheel drive without a steering servo according to claim 1, characterized in that: The first angle detection assembly and the second angle detection assembly have the same structure, and both include a magnetic encoder, an encoder bracket, a magnet and a magnet bracket; the magnetic encoder is fixedly installed on the encoder bracket, the magnet is fixedly installed on the magnet bracket, and the magnet is located directly below the magnetic encoder and is arranged opposite to it; the encoder bracket of the first angle detection assembly is fixedly installed on the middle support plate, and the magnet bracket of the first angle detection assembly is fixedly installed on the first driving gear or the second driving gear of the first gear transmission assembly; the encoder bracket of the second angle detection assembly is fixedly installed on the upper and middle support plates, and the magnet bracket of the second angle detection assembly is fixedly installed on the first driving gear or the second driving gear of the second gear transmission assembly; the magnet and the first driving gear or the second driving gear are coaxially distributed.

4. The omnidirectional mobile chassis structure of a general wheel drive without a steering servo according to claim 1, characterized in that: A first corner limit mechanism is provided between the driven gear of the first gear transmission assembly and the middle lower support plate; a second corner limit mechanism is provided between the driven gear of the second gear transmission assembly and the middle upper support plate; the first corner limit mechanism and the second corner limit mechanism have the same structure, and both include a rocker, a swing rod, a stop pin, a limit stop block, a stop block position adjustment chute and a stop block positioning screw; one end of the rocker is connected to the main body stud through a bearing, the rod body of the rocker is fixedly connected to the driven gear, and the other end of the rocker is a free end; the stop block position adjustment chute of the first gear transmission assembly is arranged on the middle lower support plate; the stop block position adjustment chute of the second gear transmission assembly is arranged on the middle upper support plate; two limit stop blocks are installed in the stop block position adjustment chute, and a stop block positioning screw is installed between the stop block position adjustment chute and the limit stop block; the middle part of the swing rod of the first gear transmission assembly is hinged to the middle lower support plate; the middle part of the swing rod of the second gear transmission assembly is hinged to the middle upper support plate; one end of the swing rod is located between the two limit stop blocks, and a stop pin is installed at the other end of the swing rod, and the stop pin is matched with the free end of the rocker.

5. The omnidirectional mobile chassis structure of a general wheel drive without a steering servo according to claim 1, characterized in that: A first installation position fine-tuning mechanism is provided between the first intermediate gear of the first gear transmission assembly and the middle lower support plate; a second installation position fine-tuning mechanism is provided between the second intermediate gear of the first gear transmission assembly and the middle lower support plate; a third installation position fine-tuning mechanism is provided between the first intermediate gear of the second gear transmission assembly and the middle support plate; a fourth installation position fine-tuning mechanism is provided between the second intermediate gear of the second gear transmission assembly and the middle support plate; the first installation position fine-tuning mechanism, the second installation position fine-tuning mechanism, the third installation position fine-tuning mechanism and the fourth installation position fine-tuning mechanism have the same structure, and all include an intermediate gear installation bolt, a gear position adjustment plate and an adjustment plate positioning screw; one end of the intermediate gear installation bolt is rotatably connected to the first intermediate gear or the second intermediate gear through a bearing, and the other end of the intermediate gear installation bolt is fixedly connected to the gear position adjustment plate; a kidney-shaped hole is formed in the gear position adjustment plate, and the adjustment plate positioning screw passes through the kidney-shaped hole and is connected to the middle lower support plate or the middle support plate; an adjustment plate limit chute is formed in the middle lower support plate or the middle support plate, and the gear position adjustment plate is located in the adjustment plate limit chute.

6. The control method of the omnidirectional mobile chassis structure of the ordinary wheel drive non-steering steering gear according to claim 1, characterized in that: When the chassis needs to perform omnidirectional translation, first establish an omnidirectional translation calculation formula, which is specifically as follows: ； Wherein, ω 1 is the rotational angular velocity of the left front wheel, ω 2 is the rotational angular velocity of the right front wheel, ω 3 is the rotational angular velocity of the right rear wheel, ω 4 is the rotational angular velocity of the left rear wheel, r is the wheel radius, b is the horizontal distance between the wheel center and the vertical rotation center of the wheel, v is the desired translational velocity, θ t is the desired wheel deflection angle, θ t-1 is the wheel deflection angle at the previous moment, t is the time; Subsequently, according to the established omnidirectional translation calculation formula, the desired wheel deflection angle is input into the PID controller θ t and the desired translation speed v , through the automatic calculation of the omnidirectional translation calculation formula, the rotational angular velocities required for the four wheels can be obtained. Furthermore, the four corresponding wheels are respectively driven by four driving motors to rotate at the calculated rotational angular velocities, realizing the omnidirectional translation of the robot. During the omnidirectional translation of the robot, the desired wheel deflection angle θ t is detected and fed back through the magnetic encoder.

7. The control method of the omnidirectional mobile chassis structure of the ordinary wheel drive without a steering servo as claimed in claim 1, characterized in that: When the chassis needs to rotate in place, first establish an in-place rotation calculation formula, which is specifically as follows: ； Wherein, ω i is the angular velocity of wheel rotation, and i = 1, 2, 3, 4, d is the horizontal distance between the geometric center of the chassis and the wheel center, r is the wheel radius, ω is the desired angular velocity of self-rotation; Afterwards, control the two wheels on the diagonal line of the left front wheel and the right rear wheel to rotate clockwise to the extreme position, and at the same time control the two wheels on the diagonal line of the right front wheel and the left rear wheel to rotate counterclockwise to the extreme position. The rotation angle of the wheels is detected and fed back by a magnetic encoder; after all four wheels rotate to the extreme position, if the chassis needs to rotate clockwise in place, use the left front wheel and the right rear wheel as the driving wheels, and use the right front wheel and the left rear wheel as the driven wheels; if the chassis needs to rotate counterclockwise in place, use the right front wheel and the left rear wheel as the driving wheels, and use the left front wheel and the right rear wheel as the driven wheels; Subsequently, according to the established in-situ rotation calculation formula, the desired angular velocity of rotation is input into the PID controller ω , and through the automatic calculation of the in-situ rotation calculation formula, the required angular velocity of wheel rotation can be obtained ω i , and then the corresponding wheels are driven by the drive motor to rotate at the calculated angular velocity of rotation, realizing the in-situ rotation of the robot.

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