A variable wheelbase angle module skateboard chassis and control method

Abstract

The invention discloses a variable wheelbase angle module skateboard chassis and control method, belonging to the field of vehicle engineering technology, the chassis includes a frame and four corner modules installed on the frame; the corner module has wheels that can rotate and turn; the frame includes a telescopic frame and two sets of side frame assemblies; the side frame assembly includes a fixed frame and two mobile frames, and the two mobile frames can move forward and backward relative to the fixed frame; the two sets of side frame assemblies are relatively arranged left and right; the telescopic frame is arranged between the two sets of side frame assemblies, and can be synchronously telescoped in the front and back, left and right directions; the two mobile frames of each set of side frame assemblies are respectively connected to the front and back ends of the corresponding sides of the telescopic frame, and the four mobile frames move synchronously with the telescopic frame; the four corner modules are respectively installed on the four mobile frames; the mobile frames are driven to move forward and backward, left and right by turning and rotating the wheels to realize the change of wheelbase. The invention realizes the change of wheelbase by self-driving the corner modules, without the need to add an additional driving device.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle engineering, and relates to a chassis with a variable wheelbase, and in particular to a skateboard chassis with a variable wheelbase angle module and a control method. Background Art

[0002] The wheel hub motor corner module is a module assembly that optimizes the design of the wheel hub motor, transmission system, braking system, steering system, and suspension system and is built into the wheel hub and suspension arm. The wheel hub motor corner module has the characteristics of flexible layout, which makes the wheel hub motor corner module vehicle not need to consider the limitations of traditional mechanical transmission. The wheels are completely decoupled, and the drive, braking, and steering of each wheel can be independently controlled. The vehicle drive, braking, and steering systems are no longer integrated on the frame, but are distributed in blocks on the four corners of the frame, and each corner module is driven by wire control. The variable wheelbase and track of the vehicle help to improve the dynamic performance. Specifically, the variable track helps to improve the lateral stability of the vehicle, and the variable wheelbase helps to improve the obstacle crossing performance of the vehicle. However, the chassis mass of traditional vehicles is large, and the variable wheelbase and track have a great impact on the stiffness of traditional vehicles. Although there are some non-traditional chassis structures that can realize the change of wheelbase and track, such as the Chinese invention patent application with publication number CN113184053A, most of their structures are too complicated and require additional drive structures, which is not conducive to practical application. Summary of the invention

[0003] The present invention provides a variable wheelbase angle module skateboard chassis and a control method to overcome the defects of the prior art.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] In the first aspect, the present invention provides a variable wheelbase angle module skateboard chassis with a wheel center on an elliptical line, comprising a frame and four corner modules mounted on the frame; the corner modules have wheels driven by a hub motor and a steering motor and capable of rotating and turning; the frame comprises a telescopic frame and two sets of side frame assemblies; the side frame assemblies comprise a fixed frame and two mobile frames, and the two mobile frames can move forward and backward relative to the fixed frame; the two sets of side frame assemblies are arranged opposite to each other left and right; the telescopic frame is arranged between the two sets of side frame assemblies and can telescope synchronously in the front, back, left and right directions; the two mobile frames of each set of side frame assemblies are respectively connected to the front and back ends of the corresponding sides of the telescopic frame, and the four mobile frames move synchronously with the telescopic frame's telescoping; the four corner modules are respectively mounted on the four mobile frames; the mobile frames are driven to move forward, back, left and right by steering and rotating the wheels to achieve changes in wheelbase and wheelbase.

[0006] Optionally, the telescopic frame is formed by a plurality of X-shaped rod groups connected transversely; the X-shaped rod group is composed of two connecting rods cross-hinged; adjacent X-shaped rod groups are connected by two connecting rod ends that are hinged to each other, thereby linking all X-shaped rod groups; the two connecting rod ends on the outer sides of the X-shaped rod groups on both sides are respectively hinged to the two movable frames of the side frame assembly on the corresponding side.

[0007] Optionally, in the side frame assembly, the fixed frame has a groove rail, and the two mobile frames are arranged opposite to each other, and the inner end extends into the groove rail and is slidably connected thereto. The "inner end" here refers to an end of the mobile frame facing the inner center direction of the side frame assembly as a whole.

[0008] Optionally, a plurality of electromagnetic locks capable of popping out lock cylinders are installed at the inner end of the mobile frame; locking holes are provided at both ends of the groove rail; the position of the locking hole matches the pop-out direction of the electromagnetic lock cylinder, and when any electromagnetic lock moves to the locking hole with the mobile frame, the pop-out lock cylinder is inserted into the locking hole, and the relative position of the mobile frame and the fixed frame is fixed; when the fixed frame and the mobile frame are locked, the wheelbase is fixed, and under the limitation of the telescopic frame, the wheelbase is also fixed.

[0009] Optionally, a plurality of the electromagnetic locks are arranged at equal intervals on the inner end of the movable frame.

[0010] Optionally, in the side frame assembly, a laser infrared ranging sensor is installed on the inner end surface of a movable frame for measuring the distance between the two movable frames.

[0011] In the second aspect, the present invention provides a control method for the above-mentioned variable wheelbase angle module skateboard chassis with the wheel center on an elliptical line: first control the steering of the wheel, then control the electromagnetic lock lock core that extends into the locking hole to be retracted, then control the two front wheels and the two rear wheels to rotate in the opposite direction, the wheelbase and track change accordingly, and the steering of the wheel is controlled synchronously; when the target wheelbase and track are reached, control the electromagnetic lock lock core corresponding to the locking hole to pop out and extend into the locking hole, and the wheelbase and track are locked.

[0012] Optionally, the steering angle of the wheel is controlled according to the distance between the two moving frames in the same side frame assembly, and the control equation is: α=arctan(s); wherein α is the steering angle and s is the distance between the two moving frames.

[0013] Optionally, the distance between the two mobile frames is filtered using a median filter, and the intermediate value within a number of cycles is taken as the measurement value of the laser infrared ranging sensor.

[0014] Optionally, when the electromagnetic lock is inserted into the locking hole, the wheelbase and the track are fixed; when different electromagnetic locks are inserted into the locking holes, the wheelbase and the track are different; according to the difference of the electromagnetic locks inserted into the locking hole, the wheelbase and the track are divided into several variable modes, and the distance between the two moving frames in the same side frame assembly in different variable modes is different; the number of electromagnetic locks is n, and the distance between the two moving frames when the lock cylinder of the i-th electromagnetic lock is inserted into the locking hole is S i , i=1~n; the time when the lock cylinder of the electromagnetic lock pops out in the corresponding variable mode is: s=[S i -e, S i +f], the lock core of the i-th electromagnetic lock pops out, where s is the distance between the two movable frames, e is the distance between the two electromagnetic locks, and f is the distance from the locking hole to the outer edge of the fixed frame.

[0015] The beneficial effects of the present invention are as follows: the present invention provides a variable wheelbase angle module skateboard chassis and control method, the frame is composed of a telescopic frame and two sets of side frame components, the wheel is rotated and turned by driving the angle module, the frame is driven to change, so as to realize the change of wheelbase and track. At the same time, the frame is also provided with a corresponding electromagnetic lock and a locking hole, which can realize the locking function, and then realize the adjustment of multi-stage variable wheelbase and track. Specifically, the variable wheelbase and track driving mode provided by the present invention is the angle module self-driving, without additional motors and other driving devices. The telescopic frame can ensure that when the four wheels move in the variable wheelbase and track mode, the positions of the four wheel centers are consistent with the center of mass of the chassis, and the positions of the four wheels relative to the center of mass are coupled and synchronously moved. Even in the variable wheelbase and track mode, when there is a slight inconsistency in the motion state of the four wheels, the coupling synchronization will also cause the wheelbase and track to change synchronously. By designing the telescopic frame and the side frame components, the trajectory of the wheel center falls within the elliptical curve, and by designing the locking holes and electromagnetic lock positions on the fixed frame and the sliding frame, the adjustment requirements of multiple groups of different wheelbases and track can be met. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of a variable wheelbase angle module skateboard chassis;

[0017] Figure 2 It is a schematic diagram of the structure of a variable wheelbase angle module skateboard chassis frame;

[0018] Figure 3 It is a schematic diagram of the structure of the variable wheelbase angle module skateboard chassis side frame assembly;

[0019] Figure 4 It is a schematic diagram of the change of the wheel center of the variable wheelbase angle module skateboard chassis on the elliptical line;

[0020] Figure 5 It is a schematic diagram of the wheel center of the variable wheelbase angle module skateboard chassis controlling the wheel steering angle;

[0021] The markings in the accompanying drawings are: 1, frame; 11, telescopic frame; 111, connecting rod; 12, side frame assembly; 121, fixed frame; 1211, groove rail; 122, mobile frame; 131, electromagnetic lock; 132, locking hole; 14, laser infrared ranging sensor; 2, corner module; 21, wheel. DETAILED DESCRIPTION

[0022] The specific implementation of the present invention is described below with reference to the accompanying drawings.

[0023] like Figure 1 As shown, the present invention provides a variable wheelbase angle module skateboard chassis with a wheel center on an elliptical line, comprising a frame 1 and four angle modules 2 mounted on the frame 1.

[0024] The corner module 2 has a wheel 21 driven by a hub motor and a steering motor, and can rotate and steer. The corner module 2 is a prior art and will not be described in detail.

[0025] like Figure 1 and Figure 2 As shown, the frame 1 includes a telescopic frame 11 and two groups of side frame assemblies 12. The side frame assembly 12 includes a fixed frame 121 and two mobile frames 122, and the two mobile frames 122 can move forward and backward relative to the fixed frame 121. The two groups of side frame assemblies 12 are arranged opposite to each other on the left and right sides. The telescopic frame 11 is arranged between the two groups of side frame assemblies 12, and can be synchronously telescoped in the front, back, left and right directions, that is, when it is extended in the front and back direction, it is shortened in the left and right direction, and when it is shortened in the front and back direction, it is extended in the left and right directions. The two mobile frames 122 of each group of side frame assemblies 12 are respectively connected to the front and back ends of the corresponding sides of the telescopic frame 11, and the four mobile frames 122 move synchronously with the extension and retraction of the telescopic frame 11. The four corner modules 2 are respectively mounted on the four mobile frames 122.

[0026] The moving frame 122 is driven to move forward, backward, left and right by turning and rotating the wheels 21, so as to achieve the change of wheelbase.

[0027] Regarding the telescopic frame 11, as Figure 2 As shown, in a specific embodiment, the telescopic frame 11 is formed by a plurality of X-shaped rod groups connected transversely. The X-shaped rod group is composed of two connecting rods 111 cross-hinged, that is, the middle part of one connecting rod 111 is hinged to the middle part of another connecting rod 111. Adjacent X-shaped rod groups are connected by hinged ends of two connecting rods 111, thereby all X-shaped rod groups are linked. The ends of the two connecting rods 111 on the outer sides of the X-shaped rod groups on both sides are respectively hinged to the two moving frames 122 of the side frame assembly 12 on the corresponding side.

[0028] Regarding the side frame assembly 12, as shown in FIG. Figure 2 and Figure 3As shown, in a specific embodiment, the fixed frame 121 has a groove rail 1211, and two movable frames 122 are arranged opposite to each other, and the inner ends thereof extend into the groove rail 1211 and are slidably connected thereto. Specifically, the inner ends of the two movable frames 122 are respectively hinged to the ends of the two connecting rods 111 on the outer sides of the corresponding side X-shaped rod groups. The corner module 2 is installed at the outer end of the movable frame 122.

[0029] like Figure 2 and Figure 3 As shown, in a preferred embodiment, a plurality of electromagnetic locks 131 capable of popping out lock cores and arranged at equal intervals are installed at the inner end of the mobile frame 122. Both ends of the groove rail 1211 have locking holes 132. The position of the locking hole 132 matches the pop-out direction of the lock core of the electromagnetic lock 131. When any electromagnetic lock 131 moves to the locking hole 132 with the mobile frame 122, the pop-out lock core is inserted into the locking hole 132, and the relative position of the mobile frame 122 and the fixed frame 121 is fixed. That is, the electromagnetic lock 131 is installed downward, and the lock core pops out downward, then the locking hole 132 is correspondingly arranged on the lower side of the end of the groove rail 1211, so that when the electromagnetic lock 131 moves to the locking hole 132, the pop-out lock core can be inserted into the locking hole 132, thereby achieving a locking effect between the fixed frame 121 and the mobile frame 122. Of course, the electromagnetic lock 131 can also be installed upward or in other directions. Accordingly, the locking hole 132 needs to be set at a position corresponding to the direction in which the lock core pops out, so that it can meet the purpose of locking. When the fixed frame 121 and the movable frame 122 are locked, the wheelbase is fixed, and under the limitation of the telescopic frame 11, the wheelbase is also fixed.

[0030] like Figure 2 and Figure 3 As shown, in a preferred embodiment, in each set of side frame assemblies 12, a laser infrared distance measuring sensor 14 is installed on the inner end surface of one mobile frame 122, which is used to measure the distance between the two mobile frames 122. Specifically, the laser infrared distance measuring sensor 14 emits light through an infrared LED to illuminate the inner end surface of another mobile frame 122, and the reflected light is received and the distance is obtained by calculating the time difference.

[0031] like Figure 4 As shown, the present invention realizes the wheelbase change of the wheel center of the wheel 21 on an elliptical trajectory through the telescopic frame 11. The elliptical trajectory specifically means that for the projection of the wheel center and the chassis center of mass in the horizontal plane, the change trajectory of the wheel center is an elliptical trajectory relative to the chassis center of mass. Therefore, a coordinate system is set with the chassis center of mass as the origin, the wheelbase direction as the x-axis, and the wheelbase direction as the y-axis. The elliptical trajectory equation of the wheel center is:

[0032] x = 0.5 × L × cosθ + a,

[0033] y = L × sinθ + b;

[0034] Wherein, a is the longitudinal distance from the inner end of the mobile frame 122 (i.e., the connection between the mobile frame 122 and the telescopic frame 11) to the wheel center, b is the lateral distance from the mobile frame 122 to the wheel, L is the length of the connecting rod 111 in the telescopic frame 11, in m, and θ is the angle between the connecting rod 111 and the x-axis.

[0035] After calculation, we get:

[0036] (x) 2 / (1 / 4)+(yb) 2 / 1=L 2 .

[0037] It can be known from the elliptical trajectory equation of the wheel center that the elliptical trajectory of the wheel center depends on the length of the connecting rod 111 in the telescopic frame 11 and the installation position of the wheel 21. The change of the elliptical trajectory of the wheel center causes the wheelbase and track to change accordingly. A number of electromagnetic locks 131 ensure the selectivity of the wheelbase and wheelbase. When the wheelbase and track reach the expected size during the movement of the wheel 21, the lock core of the electromagnetic lock 131 is inserted into the locking hole 132 of the groove rail 1211, so that the fixed frame 121 and the movable frame 122 cannot move relative to each other, thereby locking the wheelbase and track.

[0038] The control method of the variable wheelbase angle module skateboard chassis of the present invention is: first control the wheel 21 to turn, then control the electromagnetic lock 131 lock core extending into the locking hole 132 to retract, then control the two front wheels 21 and the two rear wheels 21 to rotate in the opposite direction, the wheelbase and the track change accordingly, and synchronously control the wheel 21 to turn. When the target wheelbase and track are reached, the lock core of the electromagnetic lock 131 corresponding to the locking hole 132 is controlled to pop out and extend into the locking hole 132, and the wheelbase and track are locked.

[0039] Specifically, when the vehicle control unit VCU receives an instruction from the driver to switch the variable wheelbase and track mode, the VCU sends an instruction to the steering motor controller of the corner module 2, the relay for turning on and off the electromagnetic lock 131, and the wheel hub motor controller of the corner module 2. After receiving the angle instruction from the VCU, the steering motor controller controls the steering motor to drive the wheel 21 to rotate a certain angle. The relay for controlling the on and off of the electromagnetic lock 131 is energized, so that the lock cylinder of the electromagnetic lock 131 retracts, and the fixed frame 121 and the movable frame 122 can move relative to each other to adjust the wheelbase and track of the vehicle. After receiving the rotation instruction from the VCU, the wheel hub motor controller controls the two wheel hub motors on the front side and the two wheel hub motors on the rear side to rotate in opposite directions, driving the wheelbase and track to change. At the same time, due to the changes in the wheelbase and track, the VCU synchronously calculates and controls the steering motor to drive the wheel 21 to rotate a certain angle. When the wheelbase and track reach the required state of the vehicle, the relay controlling the on and off of the electromagnetic lock 131 is powered off, the lock cylinder of the electromagnetic lock 131 pops out, and the fixed frame 121 and the movable frame 122 are limited by the lock cylinder to fix the wheelbase and track of the vehicle.

[0040] Regarding the steering angle of the wheel 21, Figure 5 As shown, the steering angle of the wheel 21 is controlled according to the distance between the two moving frames 122 in the same side frame assembly 12:

[0041] x=0.5×s+a, where s is the distance between the two moving frames 122, in meters. According to the elliptical trajectory equation of the wheel center x=0.5×L×cosθ+a, θ at the distance between the moving frames 122 is obtained. Derivative y=L×sinθ+b is used to obtain the slope of the tangent line at the wheel center on the elliptical curve at this time, y'=dy / dθ=L×cosθ, and the steering angle α=arctan(y') is calculated, that is, the control equation for the steering angle of the wheel 21 is:

[0042] α=arctan(s).

[0043] The distance between the two moving frames 122 is filtered by median, and the middle value within several cycles is taken as the measurement value of the laser infrared ranging sensor 14. The distance measured by the laser infrared ranging sensor 14 is timely and accurate. After the wheel 21 absorbs the excitation of the road surface to the wheel 21 during the movement, there is still vibration transmitted to the frame 1. At this time, there is a disturbance in the distance between the moving frames 122 measured by the laser infrared ranging sensor 14, which affects the real-time steering angle of the wheel 21, thereby aggravating the wear of the tire. The signal of the laser infrared ranging sensor 14 is processed by the filtering algorithm to obtain a more stable and accurate distance value.

[0044] Regarding the ejection timing of the lock cylinder of the electromagnetic lock 131: When the electromagnetic lock 131 is inserted into the locking hole 132, the wheelbase and the track are fixed. When different electromagnetic locks 131 are inserted into the locking hole 132, the wheelbase and the track are different. According to the difference of the electromagnetic locks 131 inserted into the locking hole 132, the wheelbase and the track are divided into several variable modes, and the distance between the two moving frames 122 in the same side frame assembly 12 is different in different variable modes. The number of electromagnetic locks 131 is n, and the distance between the two moving frames 122 when the lock cylinder of the i-th electromagnetic lock 131 is inserted into the locking hole 132 is S i , i=1~n. The time when the lock cylinder of the electromagnetic lock 131 pops out in the corresponding variable mode is: s=[S i -e,S i+f], the lock core of the i-th electromagnetic lock 131 pops out, where s is the distance between the two moving frames 122, e is the distance between the two electromagnetic locks 131, and f is the distance from the locking hole 132 to the outer edge of the fixed frame 121. That is, if the distance between the two moving frames 122 is less than the distance between the two moving frames 122 in the variable mode, that is, the two moving frames 122 need to move outward, when the distance between the two moving frames 122 is greater than the distance between the two moving frames 122 in the variable mode minus the distance between the two electromagnetic locks 131, the lock core of the electromagnetic lock 131 corresponding to the variable mode is popped out. If the distance between the two mobile frames 122 is greater than the distance between the two mobile frames 122 in the variable mode, that is, the two mobile frames 122 need to move inward, when the distance between the two mobile frames 122 is less than the distance between the two mobile frames 122 in the variable mode plus the distance from the locking hole 132 to the outer edge of the fixed frame 121, that is, the electromagnetic lock 131 corresponding to the variable mode moves into the groove rail 1211, and the lock core of the electromagnetic lock 131 pops open.

[0045] In the present invention, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art.

[0046] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0047] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A variable wheelbase angle module skateboard chassis with a wheel center on an elliptical line, comprising a frame (1) and four angle modules (2) mounted on the frame (1), the angle modules (2) having wheels (21) capable of rotating and turning, characterized in that: The vehicle frame (1) comprises a telescopic frame (11) and two sets of side frame assemblies (12); The side frame assembly (12) comprises a fixed frame (121) and two movable frames (122), and the two movable frames (122) are capable of moving forward and backward relative to the fixed frame (121); the two sets of side frame assemblies (12) are arranged relative to each other; The telescopic frame (11) is arranged between two groups of side frame assemblies (12) and can be telescoped in opposite directions in a synchronous manner in the front, back, left and right directions; the two movable frames (122) of each group of side frame assemblies (12) are respectively connected to the front and rear ends of the corresponding sides of the telescopic frame (11), and the four movable frames (122) move synchronously with the telescopic frame (11); The four corner modules (2) are respectively mounted on four movable frames (122); The moving frame (122) is driven to move forward, backward, left and right by turning and rotating the wheels (21), thereby achieving a change in wheelbase.

2. The variable wheelbase angle module skateboard chassis with the wheel center on the elliptical line according to claim 1, characterized in that: The telescopic frame (11) is formed by a plurality of X-shaped rod groups connected transversely; the X-shaped rod group is formed by two connecting rods (111) cross-hinged; adjacent X-shaped rod groups are connected by the ends of two connecting rods (111) that are hingedly connected; The ends of the two connecting rods (111) on the outsides of the X-shaped rod groups on both sides are respectively hinged to the two moving frames (122) of the side frame assembly (12) on the corresponding sides.

3. The variable wheelbase angle module skateboard chassis with the wheel center on the elliptical line according to claim 2, characterized in that: In the side frame assembly (12), the fixed frame (121) has a groove rail (1211), and the two movable frames (122) are arranged opposite to each other, with the inner ends extending into the groove rail (1211) and being slidably connected thereto.

4. The variable wheelbase angle module skateboard chassis with the wheel center on the elliptical line according to claim 3, characterized in that: A plurality of electromagnetic locks (131) capable of popping out lock cylinders are installed at the inner end of the movable frame (122); both ends of the groove rail (1211) have locking holes (132); the positions of the locking holes (132) match the pop-out directions of the lock cylinders of the electromagnetic locks (131); when any electromagnetic lock (131) moves to the locking holes (132), the pop-out lock cylinders are inserted into the locking holes (132), and the relative positions of the movable frame (122) and the fixed frame (121) are fixed.

5. The variable wheelbase angle module skateboard chassis with the wheel center on the elliptical line according to claim 4, characterized in that: A plurality of electromagnetic locks (131) are arranged at equal intervals on the inner end of the movable frame (122).

6. The variable wheelbase angle module skateboard chassis with the wheel center on the elliptical line according to claim 4, characterized in that: In the side frame assembly (12), a laser infrared distance measuring sensor (14) is installed at the inner end of a moving frame (122) for measuring the distance between the two moving frames (122).

7. The control method of a variable wheelbase angle module skateboard chassis with a wheel center on an elliptical line as claimed in claim 6, characterized in that: First, the wheel (21) is controlled to turn, and then the lock core of the electromagnetic lock (131) whose lock core extends into the locking hole (132) is controlled to be retracted, and then the two front wheels (21) and the two rear wheels (21) are controlled to rotate in the opposite direction, and the wheelbase and track width change accordingly, and the wheel (21) is controlled to turn synchronously; When the target wheelbase and track are reached, the lock core of the electromagnetic lock (131) corresponding to the locking hole (132) is controlled to pop out and extend into the locking hole (132), and the wheelbase and track are locked.

8. The control method of a variable wheelbase angle module skateboard chassis with a wheel center on an elliptical line according to claim 7, characterized in that: The steering angle of the wheel (21) is controlled according to the distance between the two moving frames (122) in the same side frame assembly (12), and the control equation is: α=arctan(s); Wherein, α is the turning angle, and s is the distance between the two moving frames (122).

9. The control method of a variable wheelbase angle module skateboard chassis with a wheel center on an elliptical line according to claim 8, characterized in that: The distance between the two moving frames (122) is filtered using a median filter, and the middle value within a number of cycles is taken as the measurement value of the laser infrared distance measuring sensor (14).

10. The control method of a variable wheelbase angle module skateboard chassis with a wheel center on an elliptical line according to claim 7, characterized in that: The wheelbase and wheel track are divided into a plurality of variable modes according to the difference of the electromagnetic locks (131) inserted into the locking hole (132); the distance between the two movable frames (122) in the same side frame assembly (12) is different in different variable modes; the number of the electromagnetic locks (131) is n, and the distance between the two movable frames (122) when the lock cylinder of the i-th electromagnetic lock (131) is inserted into the locking hole (132) is S i , i=1~n; The timing of the lock cylinder of the electromagnetic lock (131) popping out in the corresponding variable mode is: s=[S i -e, S i +f], the lock core of the i-th electromagnetic lock (131) pops out, where s is the distance between the two movable frames (122), e is the distance between the two electromagnetic locks (131), and f is the distance from the locking hole (132) to the outer edge of the fixed frame (121).

Images