CN219969775U

CN219969775U - Unmanned chassis device

Info

Publication number: CN219969775U
Application number: CN202320856732.5U
Authority: CN
Inventors: 董康泰; 姚静彤; 田子昂; 陈姝廷; 苗占海; 韩毅
Original assignee: Changan University
Current assignee: Changan University
Priority date: 2023-04-17
Filing date: 2023-04-17
Publication date: 2023-11-07
Anticipated expiration: 2033-04-17

Abstract

The utility model discloses an unmanned chassis device, comprising: the bearing bracket is fixed on the fixed bracket and is flush with the upper surface of the fixed bracket; the upper surface of the fixed bracket is provided with a chassis upper plate; the chassis side plates are arranged on the side surfaces around the fixed bracket; the wheel system is connected with a steering device through a main shaft, and the steering device is arranged on the bearing bracket. The utility model connects the wheel system with the steering device through the main shaft, and the steering device is arranged on the bearing bracket. The steering device can control the direction of each wheel to be independently controlled, 360-degree rotation is realized, the minimum turning radius is 0 m, and the unmanned vehicle can steer at a low speed under the minimum space limit, so that the unmanned vehicle is more suitable for the working requirement in a narrow space.

Description

Unmanned chassis device

Technical Field

The utility model belongs to the technical field of unmanned vehicles, and relates to an unmanned chassis device.

Background

The unmanned chassis is a multifunctional chassis mainly playing a role in bearing and transporting, has excellent mobility and bearing capacity, and integrates multiple functions of environment sensing, dynamic decision making, execution and the like. With the rapid development of technologies such as 5G technology, multi-sensor data fusion technology and drive-by-wire chassis technology, the unmanned chassis is widely applied to military, medical and scientific research, and works in dangers, narrow places and the like which cannot be achieved by people.

The existing small-range steering mode mainly comprises front wheel full-hydraulic steering and articulated steering, and the full-hydraulic steering is a hydraulic power steering mode which is connected between a steering wheel and a steering control mechanism without a connecting rod, has the advantages of light and flexible control, simple structure, convenient whole machine installation and arrangement and the like, but the turning radius is still relatively large, and can not adapt to working conditions when passing through some specific areas such as underground roadways; when the hinge turns, the two parts of the frame form a folding angle, so that the turning radius of the outer contour is reduced, and the turning radius of the inner contour is increased, so that the frame can pass through a narrow channel, but the defect is that wheels do not roll purely in the turning process, and the phenomenon of wheel sliding motion exists.

Disclosure of Invention

The utility model aims to solve the problems that in the prior art, the turning radius of a full-hydraulic steering gear is relatively large, wheels do not roll purely when a hinge steers, and safety risks exist, and provides an unmanned chassis device.

In order to achieve the purpose, the utility model is realized by adopting the following technical scheme:

an unmanned chassis device comprising: the device comprises a supporting framework, chassis side plates, a wheel system, a steering device and a main shaft;

the supporting framework comprises a fixed bracket and a bearing bracket; the bearing bracket is fixed on the fixed bracket and is flush with the upper surface of the fixed bracket; the upper surface of the fixed bracket is provided with a chassis upper plate; the chassis side plates are arranged on the side surfaces around the fixed bracket; the wheel system is connected with a steering device through a main shaft, and the steering device is arranged on the bearing bracket.

The utility model further improves that:

further, the steering device comprises a servo motor, a speed reducer and a bearing seat; the servo motor is externally connected with a servo motor controller; the servo motor controller controls the rotation of the servo motor; an output shaft of the servo motor is connected with an input end of the speed reducer through a spline, and the servo motor is fixed on a mounting hole on the speed reducer through a screw; the speed reducer is arranged on the bearing bracket; the bearing seat is arranged on the speed reducer.

Further, the number of the steering devices is four, and each servo motor is respectively connected with one servo motor controller; each servo motor controller independently controls one servo motor.

Further, the mounting hole on the upper end surface of the speed reducer is connected with the bending notch on the bearing bracket through a bolt, so that the speed reducer is connected with the bearing bracket; the lower end face of the speed reducer is provided with mounting holes which are uniformly distributed along the main shaft and correspond to the bearing seat, and the speed reducer is fixedly connected with the bearing seat through the mounting holes of the lower end face of the speed reducer.

Further, the wheel system comprises a wheel, calipers, a caliper bracket, a brake disc, a shock absorber and a shock absorber tower top; the brake discs are arranged on two sides of the wheels, the brake discs are positioned on the inner side of the sealing plate, the lower parts of the shock absorbers are symmetrically arranged on the outer side of the sealing plate, the upper parts of the shock absorbers are arranged in cylindrical holes on the tower top of the shock absorbers, and when the vehicle runs on a road with bumpy ground, the shock absorbers slide upwards along the cylindrical holes on the tower top of the shock absorbers to slow down the impact force; the calliper sets up on the calliper support, and the calliper support sets up on the bumper shock absorber, and the inside cavity of calliper is passed to the brake disc.

Further, the top of the shock absorber tower is provided with a middle hole, the bearing seat is provided with a round hole, and the main shaft penetrates through the middle hole of the shock absorber tower, the round hole of the bearing seat and the speed reducer and connects the shock absorber tower with the speed reducer through a nut; the main shaft rotates in the bearing seat to drive the wheel system.

Further, the reducer is in meshed connection with the main shaft through an external spline on the outer side of the main shaft and an internal spline on the inner side of an output shaft of the reducer.

Further, the brake disc is disc-shaped, the center is hollow, the brake disc is positioned on the inner side of the sealing plate, the caliper is externally connected with a brake controller, and the brake controller controls the caliper to realize a braking function on the force of the brake disc.

Further, the wheel is internally provided with a hub motor, and the wheel shaft of the hub motor is fixed through U-shaped grooves on sealing plates on two sides of the wheel; the rotor of the hub motor is connected with the hub rim of the wheel to drive the wheel to rotate; the hub motor is externally connected with a hub motor controller, and the hub motor controller independently outputs different rotating speeds and torques.

Further, the hub motor is a direct current brushless hub servo motor.

Compared with the prior art, the utility model has the following beneficial effects:

the utility model connects the wheel system with the steering device through the main shaft, and the steering device is arranged on the bearing bracket. The steering device can control the direction of each wheel to be independently controlled, 360-degree rotation is realized, the minimum turning radius is 0 m, and the unmanned vehicle can steer at a low speed under the minimum space limit, so that the unmanned vehicle is more suitable for the working requirement in a narrow space.

Furthermore, the hub motor is a direct-current brushless hub servo motor, has no electric brush, does not generate sparks in the use process, and obviously reduces heating and noise; the precision is high, the position, the speed and the moment can be controlled in a closed loop, the high-speed performance is good, and the high-speed response of the chassis can be realized; the device has strong timeliness and adaptability, can accelerate and decelerate the chassis in a shorter time, and is very suitable for occasions requiring instant load fluctuation and quick start.

Furthermore, the built-in hub motor independently drives the vehicle and has the characteristic that the longitudinal force of each wheel is independently controllable. The independent driving can generate an additional yaw moment by adjusting the difference value of the left and right longitudinal forces, and even one-side driving and one-side braking can be realized to generate a larger additional yaw moment under the extreme working condition, so that the lateral and yaw movement of the vehicle can be controlled, and the steering stability of the vehicle can be effectively improved.

Drawings

For a clearer description of the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of the overall structure of the unmanned chassis apparatus of the present utility model;

FIG. 2 is a schematic view of the bottom structure of the unmanned chassis apparatus of the present utility model;

FIG. 3 is a side cross-sectional view of the unmanned chassis apparatus of the present utility model;

FIG. 4 is a schematic view of a partial construction of a wheel system and steering apparatus;

fig. 5 is a schematic diagram of the mounting relationship of the bearing bracket and the fixing bracket.

Wherein, 1-chassis upper plate; 2-fixing a bracket; 3-chassis side panels; 4-wheel systems; 5-steering means; 6-a main shaft; 7-a nut; 8-bearing brackets; 101-fixing holes; 301-fixing holes; 401-wheels; 402-calipers; 403-calliper bracket; 404-brake disc; 405-sealing plates; 406-a shock absorber; 407-damper overhead; 408-first mounting holes, 409-second mounting holes; 501-bearing seats; 502-a decelerator; 503-a servo motor; 801-third mounting holes.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the embodiments of the present utility model, it should be noted that, if the terms "upper," "lower," "horizontal," "inner," and the like indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, or the azimuth or the positional relationship in which the inventive product is conventionally put in use, it is merely for convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the apparatus or element to be referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

Furthermore, the term "horizontal" if present does not mean that the component is required to be absolutely horizontal, but may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the embodiments of the present utility model, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" should be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

The utility model is described in further detail below with reference to the attached drawing figures:

referring to fig. 1, 2, 3, 4 and 5, the present utility model discloses an unmanned chassis device, comprising: the steering device comprises a supporting framework, a chassis side plate 3, a wheel system 4, a steering device 5 and a main shaft 6;

the supporting framework comprises a fixed bracket 2 and a bearing bracket 8; the bearing bracket 8 is fixed on the fixed bracket 2, and the bearing bracket 8 is flush with the upper surface of the fixed bracket 2; the upper surface of the fixed bracket 2 is provided with a chassis upper plate 1; the chassis side plates 3 are arranged on the side surfaces around the fixed bracket 2; the wheel system 4 is connected to a steering device 5 via a spindle 6, the steering device 5 being arranged on a carrier bracket 8. The chassis upper plate 1 is of a rectangular plate structure, and a plurality of fixing holes 101 are formed in the chassis upper plate 1 and can be fixedly connected to the fixing support 2. The chassis side plate 3 has a rectangular plate structure, and a plurality of fixing holes 301 are formed in the chassis side plate and can be fixedly connected to the fixing support 2.

The steering device 5 comprises a servo motor 503, a speed reducer 502 and a bearing seat 501; the servo motor 503 is externally connected with a servo motor controller; the servo motor controller controls the rotation of the servo motor 503; an output shaft of the servo motor 503 is connected with an input end of the speed reducer 502 through a spline, and the servo motor 503 is fixed on a mounting hole on the speed reducer 502 through a screw; the decelerator 502 is mounted on the bearing bracket 8 through the third mounting hole 801; the bearing housing 501 is provided on the decelerator 502. The third mounting hole 801 is provided on the carrier bracket 8.

Four steering devices 5 are provided, and each servo motor 503 is respectively connected with one servo motor controller; each servo motor controller independently controls one servo motor 503.

The mounting hole of the upper end surface of the speed reducer 502 is connected with the bending notch on the bearing bracket 8 through a bolt, so that the speed reducer 502 is connected with the bearing bracket 8; the lower end face of the speed reducer 502 is provided with mounting holes which are uniformly distributed along the main shaft 6 and correspond to the bearing seat 501, and the speed reducer 502 is fixedly connected with the bearing seat 501 through the mounting holes of the lower end face of the speed reducer 502.

The wheel system 4 comprises a wheel 401, a caliper 402, a caliper bracket 403, a brake disc 404, a shock absorber 406 and a shock absorber tower top 407; the brake discs 404 are arranged on two sides of the wheel 401, the brake discs 404 are positioned on the inner side of the sealing plate 405, the lower parts of the shock absorbers 406 are symmetrically arranged on the outer side of the sealing plate 405, the upper parts of the shock absorbers 406 are arranged in cylindrical holes of the shock absorber tower top 407, and when the vehicle runs on a road with bumpy ground, the shock absorbers 406 slide upwards along the cylindrical holes of the shock absorber tower top 407 to slow down the impact force; the caliper 402 is disposed on the caliper bracket 403 through the first mounting hole 408, the caliper bracket 403 is disposed on the damper 406, and the brake disc 404 passes through the inner cavity of the caliper 402.

The damper tower top 407 is provided with a middle hole, the bearing seat 501 is provided with a round hole, and the main shaft 6 passes through the middle hole of the damper tower top 407, the round hole of the bearing seat 501 and the speed reducer 502 and connects the damper tower top 407 with the speed reducer 502 through the nut 7; the spindle 6 rotates in the bearing housing 501, driving the wheel system.

The reducer 502 is engaged with the main shaft 6 through external splines on the outer side of the main shaft and internal splines on the inner side of an output shaft of the reducer 502.

The brake disc 404 is disc-shaped, the center is hollow, the brake disc 404 is positioned on the inner side of the sealing plate 405, the caliper 402 is externally connected with a brake controller, and the brake controller controls the magnitude of the force of the caliper 402 on the brake disc 404 to realize a braking function.

Wheel 401 is internally provided with a hub motor, and the wheel axle of the hub motor is fixed through U-shaped grooves on sealing plates 405 on two sides of the wheel 401; the rotor of the hub motor is connected with the hub rim of the wheel 401 to drive the wheel 401 to rotate; the hub motor is externally connected with a hub motor controller, and the hub motor controller independently outputs different rotating speeds and torques.

Examples:

the utility model provides an unmanned chassis structure, includes chassis upper plate 1, fixed bolster 2, chassis curb plate 3, wheel system 4, four sets of independent turning device 5, and turning device 5 cooperation is in the top of wheel system 4, is furnished with servo motor and reduction gear drive wheel system and carries out all-wheel steering.

The wheel system 4 includes a wheel 401 driven by an in-wheel motor, sealing plates 405 positioned on either side of the wheel and serving to fix the position of the wheel, shock absorbers 406 mounted on the sealing plates 405, a shock absorber tower top 407 receiving the shock absorbers, a brake disc 404, and calipers 402 mated therewith. In the wheel system 4, a wheel 401 is driven by a built-in hub motor, and a hub motor rotor is connected with a hub rim of the wheel 401 to drive the wheel to rotate; supporting a hub motor stator by a hub bearing; the outer side of the tire 401 is provided with evenly distributed grooves, and a direct current brushless hub servo motor is selected as the hub motor; in the sealing plates 405, each wheel is provided with a pair of sealing plates 405, which are distributed on two sides of the wheel, each sealing plate 405 is connected with a pair of shock absorbers 406, a U-shaped notch is formed at the fixed wheel, and the U-shaped notch is arranged at the middle point of the lower part of the sealing plate 405 and is matched and fixed with the shaft ends on the wheel. The hub motor is controlled by the hub motor controller, and can independently output different rotating speeds and torques, so that a large number of transmission parts can be omitted due to the fact that a traditional driving mode is omitted, and the whole vehicle structure is simplified.

In the shock absorber 406 and the shock absorber tower top 407 which bear shock absorption and buffering in the wheel system 4, the shock absorption component comprises four shock absorbers 406 and one shock absorber tower top 407, the four shock absorbers 406 are symmetrically distributed on two sides of the wheel 401, and the lower ends of the shock absorbers 406 are fixed on two side sealing plates 405; the upper parts of the four dampers 406 are fitted in cylindrical recesses in the damper tower top 407; the shock absorber tower top 407 has four cylindrical grooves, cooperates with the shock absorber 406, and when the vehicle runs on a road with bumpy ground, the shock absorber 406 can slide upwards along the cylindrical hole, and part of acting force can be buffered by the shock absorber tower top 407, so that acting force acting on the chassis is reduced, and impact on the chassis is reduced. The center of the bottom surface of the damper tower top 407 is provided with a cylindrical fixing groove, the diameter of the connecting part of the main shaft 6 is smaller than that of the fixing groove, the inner diameter of the fixing groove is equal to that of the fixing groove, and the main shaft 6 passes through the fixing groove and is locked and fixed on the speed reducer 502 through a nut 7.

In the brake disc 404 and the calipers 402 in the wheel system 4, the brake disc 404 is a circular disc made of metal material, a plurality of bending notches are uniformly distributed on the circular disc, the center of the brake disc 404 is hollow, six second mounting holes 409 are uniformly distributed on the circular disc, and the brake disc 404 passes through a wheel shaft and is tightly connected with a wheel outer hub through screws; the brake disc 404 is located inside the closure plate 405; the middle of one side of the caliper 402, which is close to the brake disc 404, is provided with a rectangular groove which is slightly larger than the thickness of the brake disc 404, and the caliper 402 is fixedly connected with a caliper bracket 403 fixed on a sealing plate 405 and a shock absorber 406 through screws. The caliper 402 is fixed on the caliper bracket 403 through screws, so that the brake disc passes through the inner cavity of the caliper, the caliper 402 is controlled by a brake controller, and the braking function is realized through the magnitude of the force of the caliper 402 to the brake disc 404.

The steering device 5 includes a servo motor 503, a decelerator 502, and a bearing housing 501. The upper end face of the bearing bracket 8 is provided with a bending moving notch corresponding to the upper end face of the speed reducer 502 and a mounting hole with a diameter slightly larger than that of the main shaft 6, a larger space is reserved near the inner side of the chassis, the lower side is not sealed, and the whole bearing bracket is welded and fixed on the fixed bracket 2. A curved notch is formed in the upper end face of the bearing bracket 8, and the upper end face of the bearing bracket 8 is connected with the upper end face of the speed reducer 502 by the curved notch.

An output shaft of the servo motor 503 is connected to an input end bearing seat of the speed reducer 502 through a key, power is transmitted, and mounting holes are reserved at corresponding positions of the speed reducer 502 and the servo motor 503 to be fastened through screws.

The mounting holes on the upper end surface of the speed reducer 502 are in screw connection with the bending notch on the bearing bracket 8, so that the connection between the speed reducer 502 and the bearing bracket 8 is realized, four mounting holes which are uniformly distributed along the main shaft 6 and correspond to the bearing seat are arranged on the lower end surface of the speed reducer 502, and the speed reducer 502 is fixedly connected with the bearing seat 501 through the mounting holes on the lower end surface of the speed reducer 502; the decelerator 502 is connected to the spindle 6 through a key groove on the outside of the spindle and the inside of the decelerator output shaft.

The servo motor 503 is a driving part, the servo motor 503 is controlled by a servo motor controller, torque is output, the torque direction is changed through the speed reducer 502, and after the speed reducer is decelerated, steering actions are transmitted to the wheel system 4 through the main shaft 6, so that steering is realized; because the steering device 5 is independently controlled, the direction of each wheel can be independently controlled to realize 360-degree rotation, and the minimum turning radius is 0 m.

The wheel system 4 and the steering device 5 are connected through a main shaft 6, the lower part of the main shaft 6 is connected with the wheel system 4, the upper part of the main shaft 6 is connected with the steering device 5 through a key, and the upper end of the main shaft 6 is fixed through a nut 7.

The above is only a preferred embodiment of the present utility model, and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. An unmanned chassis apparatus, comprising: the steering device comprises a supporting framework, chassis side plates (3), a wheel system (4), a steering device (5) and a main shaft (6);

the supporting framework comprises a fixed bracket (2) and a bearing bracket (8); the bearing bracket (8) is fixed on the fixed bracket (2), and the bearing bracket (8) is flush with the upper surface of the fixed bracket (2); the upper surface of the fixed bracket (2) is provided with a chassis upper plate (1); the chassis side plates (3) are arranged on the side surfaces around the fixed support (2); the wheel system (4) is connected with a steering device (5) through a main shaft (6), and the steering device (5) is arranged on a bearing bracket (8).

2. The unmanned chassis arrangement according to claim 1, wherein the steering arrangement (5) comprises a servo motor (503), a decelerator (502) and a bearing housing (501); the servo motor (503) is externally connected with a servo motor controller; the servo motor controller controls the rotation of a servo motor (503); an output shaft of the servo motor (503) is connected with an input end of the speed reducer (502) through a spline, and the servo motor (503) is fixed on a mounting hole on the speed reducer (502) through a screw; the speed reducer (502) is arranged on the bearing bracket (8); the bearing seat (501) is arranged on the speed reducer (502).

3. The unmanned chassis device according to claim 2, wherein the number of steering devices (5) is four, each servo motor (503) being connected to a servo motor controller; each of the servo motor controllers independently controls one servo motor (503).

4. The unmanned chassis device according to claim 3, wherein the mounting hole of the upper end surface of the speed reducer (502) is connected with the bending notch on the bearing bracket (8) through a bolt, so as to realize the connection of the speed reducer (502) and the bearing bracket (8); the lower end face of the speed reducer (502) is provided with mounting holes which are uniformly distributed along the main shaft (6) and correspond to the bearing seat (501), and the speed reducer (502) is fixedly connected with the bearing seat (501) through the mounting holes of the lower end face of the speed reducer (502).

5. The unmanned chassis arrangement according to claim 4, wherein the wheel system (4) comprises wheels (401), calipers (402), caliper brackets (403), brake discs (404), shock absorbers (406) and shock absorber towers (407);

the brake discs (404) are arranged on two sides of the wheel (401), the brake discs (404) are positioned on the inner side of the sealing plate (405), the lower parts of the shock absorbers (406) are symmetrically arranged on the outer side of the sealing plate (405), the upper parts of the shock absorbers (406) are arranged in cylindrical holes of the shock absorber tower tops (407), and when the vehicle runs on a road with bumpy ground, the shock absorbers (406) slide upwards along the cylindrical holes of the shock absorber tower tops (407) to slow down impact force; the caliper (402) is arranged on a caliper bracket (403), the caliper bracket (403) is arranged on a shock absorber (406), and the brake disc (404) passes through an inner cavity of the caliper (402).

6. The unmanned chassis device according to claim 5, wherein the damper tower top (407) is provided with a middle hole, the bearing housing (501) is provided with a round hole, and the main shaft (6) passes through the middle hole of the damper tower top (407), the round hole of the bearing housing (501) and the decelerator (502) and connects the damper tower top (407) with the decelerator (502) by means of a nut (7); the main shaft (6) rotates in the bearing seat (501) to drive the wheel system.

7. The unmanned chassis device according to claim 6, wherein the decelerator (502) is engaged with the main shaft (6) via external splines on the outer side of the main shaft and internal splines on the inner side of the output shaft of the decelerator (502).

8. The unmanned chassis device according to claim 7, wherein the brake disc (404) is disc-shaped and hollow in the center, the brake disc (404) is located inside a sealing plate (405), the caliper (402) is externally connected with a brake controller, and the brake controller controls the magnitude of the force of the caliper (402) on the brake disc (404) to realize a braking function.

9. The unmanned chassis device according to claim 8, wherein the wheel (401) is internally provided with a hub motor, and the wheel axle of the hub motor is fixed by a U-shaped groove on the sealing plates (405) at both sides of the wheel (401); the rotor of the hub motor is connected with the hub rim of the wheel (401) to drive the wheel (401) to rotate; the hub motor is externally connected with a hub motor controller, and the hub motor controller independently outputs different rotating speeds and torques.

10. The unmanned chassis apparatus of claim 9, wherein the in-wheel motor is a dc brushless in-wheel servo motor.