Straight gear rack type man-machine co-driving dual-mode steering system of driverless racing car

Abstract

The invention relates to an unmanned racing car straight gear rack type man-machine co-driving dual-mode steering system which comprises a control mechanism, a steering gear and a transmission mechanism, the control mechanism comprises a steering wheel, a steering column transmission mechanism and a lower steering column gear, and the steering gear comprises a reversing gear box, a rack and a displacement sensor. The transmission mechanism comprises a motor, a speed reducer and an electromagnetic clutch; the steering wheel is in transmission connection with the lower steering column gear through the steering column transmission mechanism, and the lower steering column gear is connected with the reversing gear box in a matched mode and penetrates through the reversing gear box to be connected with the rack in a matched mode. The output end of the motor is connected with the speed reducer which is connected with the reversing gear box in a matched mode through the electromagnetic clutch. And the displacement sensor is linked with the rack so as to detect the displacement of the rack in real time. The system can flexibly achieve switching between manual operation and unmanned operation, steering is flexible and smooth, and the response speed is high.

Description

Technical Field

[0001] The invention relates to the field of steering systems, and in particular to a spur gear rack type human-machine co-driving dual-mode steering system for an unmanned racing car. Background Art

[0002] The mechanical rack and pinion steering system is a classic steering mechanism that is widely used in various types of automobiles and engineering vehicles. When the driver turns the steering wheel, the steering shaft drives the pinion in the steering gear to rotate, which in turn drives the meshing rack to move linearly. The rack then transmits the motion to the wheels through the steering rod to achieve the steering of the vehicle.

[0003] In Formula Student racing, mechanical rack and pinion steering systems are widely used due to their simple, compact structure and high transmission efficiency. The steering system is the main system related to the performance of the racing car. It is a mechanism used to maintain or change the driving direction of the racing car. When the racing car is driving, it ensures that there is a coordinated angle relationship between the steering wheels. The performance of the system directly affects the performance of the racing car. This system can not only meet the steering requirements of the racing car under high-speed driving and intense control, but also reduce the manufacturing cost and maintenance difficulty of the racing car to a certain extent. However, the existing steering system has the following problems: (1) The existing steering system mostly uses copper sleeves and racks in direct contact, resulting in excessive friction. The racks are easily rusted and stuck when exposed to the outside for a long time. (2) Most of the existing steering systems do not have the human-machine co-driving function. For some steering systems that have the human-machine co-driving function, the connection gap between the unmanned operating system and the steering mechanical structure is too large, resulting in the unmanned operating system being insensitive. Summary of the invention

[0004] The purpose of the present invention is to provide a dual-mode steering system for unmanned racing car with spur gear and rack, which can flexibly realize the switching between manual operation and unmanned operation, and has flexible and smooth steering and fast response speed.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an unmanned racing car spur gear rack type human-machine co-driving dual-mode steering system, including an operating mechanism, a steering gear and a transmission mechanism, the operating mechanism includes a steering wheel, a steering column transmission mechanism and a lower steering column gear, the steering gear includes a reversing gear box, a rack and a displacement sensor, the transmission mechanism includes a motor, a reducer and an electromagnetic clutch; the steering wheel is connected to the lower steering column gear through the steering column transmission mechanism, the lower steering column gear is connected to the reversing gear box, and is connected to the rack through the reversing gear box; the output end of the motor is connected to the reducer, and the reducer is connected to the reversing gear box through the electromagnetic clutch; the displacement sensor is linked to the rack to detect the displacement of the rack in real time.

[0006] Furthermore, the steering column transmission mechanism includes an upper steering column and an intermediate steering column, the output shaft of the steering wheel is fixedly connected to the first connecting end of the upper steering column, the second connecting end of the upper steering column is connected to the first connecting end of the intermediate steering column through a universal joint, and the second connecting end of the intermediate steering column is connected to the lower steering column gear through a universal joint.

[0007] Furthermore, the upper steering column is mounted on a bearing seat to provide stable support for the steering wheel.

[0008] Furthermore, the output shaft of the steering wheel is a spline shaft, and the spline shaft is connected to the first connecting end of the upper steering column via a key.

[0009] Furthermore, the lower steering column gear and the rack both adopt a spur gear structure.

[0010] Furthermore, it includes a gear box bracket, the reversing gear box is installed on the gear box bracket, and the gear box bracket is installed on the system installation base plate; the reversing gear box has a reversing gear transmission mechanism, and the reversing gear transmission mechanism is connected with the lower steering column gear.

[0011] Furthermore, it comprises a rack housing, wherein the rack is installed in the rack housing and moves forward and backward in the rack housing under the drive of the lower steering column gear; the rack housing is installed in the gear box bracket.

[0012] Furthermore, the steering gear includes an upper bracket of a displacement sensor and a lower bracket of a displacement sensor, the upper bracket of the displacement sensor and the lower bracket of the displacement sensor are connected to form a sensor installation space, the displacement sensor is slidably installed in the sensor installation space, and the lower bracket of the displacement sensor is installed on the system installation base plate.

[0013] Furthermore, the electromagnetic clutch comprises an electromagnetic clutch upper plate and an electromagnetic clutch lower plate, the electromagnetic clutch upper plate is cooperatively connected to a reversing gear box, and the electromagnetic clutch lower plate is cooperatively connected to a reducer.

[0014] Furthermore, the reducer is fixedly mounted on the system mounting base plate through a motor bracket.

[0015] Compared with the prior art, the present invention has the following beneficial effects: the present invention provides a dual-mode steering system for human-machine co-driving of an unmanned racing car with spur gear rack, which can flexibly realize the switching between manual operation and unmanned operation, and the structure and transmission design are scientific and reasonable, the steering operation is flexible and smooth, the friction is small, the reaction is sensitive, and the response speed is fast, which enhances the handling performance of the racing car under high-speed driving and complex track conditions. In the unmanned driving mode, the racing car can also adapt to track changes more quickly and achieve more precise and stable driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a three-dimensional diagram of the system structure of an embodiment of the present invention; Figure 2 is a plan perspective view of the system structure of an embodiment of the present invention; Figure 3 Schematic diagram of the structure of the rack housing in an embodiment of the present invention.

[0017] In the figure: 1. Motor; 2. Speed ​​reducer; 3. Motor bracket; 4. System mounting base plate; 5. Electromagnetic clutch lower plate; 6. Electromagnetic clutch upper plate; 7. Reversing gear box; 8. Gear box bracket; 9. Lower steering column gear; 10. Universal joint; 11. Intermediate steering column; 12. Upper steering column; 13. Bearing seat; 14. Steering wheel; 15. Ear piece; 16. Rack housing; 17. Displacement sensor lower bracket; 18. Displacement sensor upper bracket; 19. Displacement sensor; 20. Top screw; 21. Quick release; 22. Spline shaft; 23. Rack; 24. Rack support upper housing; 25. Translation bearing; 26. Rack support lower housing. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0019] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0020] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0021] like Figure 1 , 2As shown, this embodiment provides a human-machine co-driving dual-mode steering system of an unmanned racing car with spur gears and racks, including an operating mechanism, a steering gear and a transmission mechanism, wherein the operating mechanism includes a steering wheel 14, a steering column transmission mechanism and a lower steering column gear 9, the steering gear includes a reversing gear box 7, a rack 15 and a displacement sensor 19, and the transmission mechanism includes a motor 1, a reducer 2 and an electromagnetic clutch; the steering wheel 14 is connected to the lower steering column gear 9 through the steering column transmission mechanism, the lower steering column gear 9 is connected to the reversing gear box 7, and is connected to the rack 23 through the reversing gear box 7; the output end of the motor 1 is connected to the reducer 2, and the reducer 2 is connected to the reversing gear box 7 through the electromagnetic clutch; the displacement sensor 19 is linked with the rack 23 to detect the displacement of the rack in real time.

[0022] The steering column transmission mechanism includes an upper steering column 12 and an intermediate steering column 11, the output shaft of the steering wheel 14 is fixedly connected to the first connecting end of the upper steering column 12, the second connecting end of the upper steering column 12 is connected to the first connecting end of the intermediate steering column 11 through a universal joint, and the second connecting end of the intermediate steering column 11 is connected to the lower steering column gear 9 through a universal joint 10.

[0023] The upper steering column 12 is mounted on a bearing seat 13 to provide stable support for the steering wheel.

[0024] The output shaft of the steering wheel 14 is a spline shaft 22 , and the spline shaft 22 is connected to the first connecting end of the upper steering column 12 via a key.

[0025] In this embodiment, the steering wheel 14 is hollowed out after simulation analysis to reduce weight, and its handle is designed according to ergonomic principles to improve the driver's operating feel. Its installation position, angle and height are calculated to meet the spatial structure of the racing frame and competition rules. At the same time, the sturdy bearing seat 13 provides stable support for the steering wheel, and the double bearing fixation inside helps to improve stability, ensure that the steering wheel rotates smoothly during high-speed driving, reduce friction and wear, and bring a smooth control experience to the driver.

[0026] The lower steering column gear 9 and the rack 23 both adopt a spur gear structure.

[0027] The system also includes a gear box bracket 8, the reversing gear box 7 is mounted on the gear box bracket 8, and the gear box bracket 8 is mounted on the system mounting base plate 4; the reversing gear box 7 has a reversing gear transmission mechanism, and the reversing gear transmission mechanism is connected with the lower steering column gear 9.

[0028] The system also includes a rack housing 16, in which the rack 23 is installed. The rack 23 moves forward and backward in the rack housing under the drive of the lower steering column gear 9, thereby converting into lateral movement of the ears 15 at both ends of the rack 23; the rack housing 16 is installed in the gear box bracket 8.

[0029] In this embodiment, the steering gear also includes an upper bracket 18 for a displacement sensor and a lower bracket 17 for a displacement sensor. The upper bracket 18 for the displacement sensor and the lower bracket 17 for the displacement sensor are connected together to form a sensor installation space. The displacement sensor 19 is slidably installed in the sensor installation space, and the lower bracket 17 for the displacement sensor is installed on the system installation base plate 4.

[0030] The steering gear is the core of the racing car steering system. This system adopts an efficient and economical gear rack design. The rack housing 16 of the steering gear is sturdy and durable. The lower steering column gear 9 and the rack 23 both adopt a straight tooth structure, which is tightly matched and easy to disassemble and assemble, achieving efficient transmission. Figure 3 As shown, the system also makes innovative improvements to the connection between the rack and the rack housing. A translation bearing 25 is introduced into the rack support housing part between the rack and the base plate to replace the traditional brass bushing. The translation bearing 25 is wrapped by the rack support upper housing 24 and the rack support lower housing 26 on the rack housing 16 and fixed on the base plate 4, thereby further reducing the friction resistance during the steering process, making the steering action smoother and improving the handling performance of the entire vehicle.

[0031] The electromagnetic clutch comprises an electromagnetic clutch upper plate 6 and an electromagnetic clutch lower plate 5, wherein the electromagnetic clutch upper plate 6 is connected with a reversing gear box 7, and the electromagnetic clutch lower plate 5 is connected with a reducer 2. The reducer 2 is fixedly mounted on a system mounting base plate 4 via a motor bracket 3.

[0032] The design of the transmission mechanism is directly related to the steering performance of the wheels and the stability of the vehicle. This system has been deeply optimized for the steering trapezoidal mechanism. The position of the disconnection point of the steering trapezoidal mechanism is accurately calculated through the three-center theorem to ensure that the wheels maintain a coordinated angle relationship when turning. At the same time, the M program is written using MATLAB software to optimize the three key parameters of the steering trapezoidal mechanism, and the optimal design scheme is obtained by comprehensively considering factors such as steering sensitivity, minimum turning radius and cornering performance. This optimization process not only improves the steering performance of the car, but also enhances its adaptability on complex tracks.

[0033] In order to cope with the development trend of unmanned driving technology in the future, this system incorporates unmanned system design. The system integrates key components such as motor 1, reducer 2, electromagnetic clutch 5, 6, reversing gearbox 7 and displacement sensor 19. The entire unmanned system is arranged in front of the cab to free up more space for the driver. The efficient cooperation of motor 1 and reducer 2 provides sufficient power support for the steering system; the flexible switching of electromagnetic clutch 5, 6 realizes the seamless conversion between mechanical operation and unmanned system operation; displacement sensor 19 can monitor the steering wheel angle in real time, and the feedback data is retransmitted to the motor to form a closed-loop control, ensuring the accuracy of wheel steering by the unmanned system. This system uses a more precise reversing gearbox 7, which reduces the gear gap between the unmanned system and the mechanical structure, and can improve the response speed of the unmanned system. This design not only improves the intelligence level of the racing car, but also lays a solid foundation for the development of unmanned racing cars in the future.

[0034] 1. Implementation of manual operating system: The steering wheel 14 is directly connected to the quick release device 21, which is connected to the spline shaft 22 through a slot to transmit torque and quick plug and unplug. The spline shaft 22 is welded to the upper steering column 12. The upper steering column 12 and the two bearings in the bearing seat 13 are interference-fitted to fix the steering system. The upper steering column 12, the middle steering column 11, and the lower steering column gear 9 are connected through a universal joint 10, which can flexibly transmit torque. The lower steering column gear 9 is connected to the rack 23 for transmission. Through this series of operations, the rotation of the steering wheel 14 is converted into the lateral movement of the ear piece 15.

[0035] In manual operation mode, the driver controls the steering of the car by turning the steering wheel. At this time, the electromagnetic clutch is in a disconnected state to ensure the independence of the mechanical transmission path. The rotation of the steering wheel is first transmitted to the upper steering column. Through the flexible connection of the universal joint, the power is smoothly transmitted to the middle steering column and finally to the lower steering column gear. The lower steering column gear is tightly meshed with the rack, and the rack slides smoothly under the precise support of the translation bearing, thereby driving the wheels to achieve steering. In this process, the driver can directly feel the steering feedback and flexibly adjust the steering wheel rotation angle and speed according to road conditions and driving needs.

[0036] 2. Implementation of unmanned operating system: The motor 1 is connected to the reducer 2 to increase the torque, the reducer 2 is connected to the electromagnetic clutch lower plate 5, and the reversing gear box 7 is connected to the electromagnetic clutch upper plate 6. The access of the unmanned system can be controlled by the switch of the electromagnetic clutch. The reversing gear box 7 and the lower steering column gear 9 are matched by keys to convert the longitudinal rotation of the lower steering column gear 9 into the lateral rotation of the output shaft through the meshing of two bevel gears.

[0037] In the unmanned system operation mode, the electromagnetic clutch is engaged and the steering system is driven by the motor. The motor is connected through a reducer to effectively increase the output torque and ensure that the steering system has sufficient driving force. Subsequently, the power output by the motor is directly transmitted to the reversing gearbox through the electromagnetic clutch. The reversing gearbox is closely connected to the lower steering column gear, and accurately controls the moving direction and distance of the rack according to the instructions of the unmanned system. At the same time, the displacement sensor is connected to the rack to monitor the moving position of the rack in real time, that is, the steering wheel angle information. These data are fed back to the unmanned system in real time and form a closed-loop control system with the motor control unit. By continuously adjusting the output power and direction of the motor, the unmanned system can achieve precise control of the steering system and improve the stability and safety of the racing car in the unmanned driving state.

[0038] When switching between the two operating modes, the electromagnetic clutch's quick response and reliable operation are essential. It ensures seamless switching between manual and unmanned system operation, allowing the car to flexibly choose the operating mode according to different driving scenarios and needs. In addition, the design of this patented product fully considers the complexity and challenges of racing events, and improves the overall performance and reliability of the racing car steering system by optimizing the transmission mechanism, introducing a translation bearing, and adopting a precision reversing gearbox.

[0039] The unmanned racing car spur gear rack type human-machine co-driving dual-mode steering system provided by the present invention is designed for the Formula Student racing event, and is intended to improve the steering performance and handling stability of the racing car. Through the innovative structural design of the system, the driver's control burden can be effectively reduced, and the steering flexibility and response speed of the racing car can be improved. In the event, the racing car will be able to adapt to track changes more quickly and achieve more accurate and stable driving performance. At the same time, the system is also suitable for the transformation and upgrading of other types of racing cars and vehicle steering systems, contributing to the technological progress and performance improvement in the racing field.

[0040] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A spur gear rack type dual-mode steering system for unmanned racing cars, characterized in that: It includes an operating mechanism, a steering gear and a transmission mechanism. The operating mechanism includes a steering wheel, a steering column transmission mechanism and a lower steering column gear. The steering gear includes a reversing gear box, a rack and a displacement sensor. The transmission mechanism includes a motor, a reducer and an electromagnetic clutch. The steering wheel is connected to the lower steering column gear through the steering column transmission mechanism. The lower steering column gear is connected to the reversing gear box and is connected to the rack through the reversing gear box. The output end of the motor is connected to the reducer, and the reducer is connected to the reversing gear box through the electromagnetic clutch. The displacement sensor is linked to the rack to detect the displacement of the rack in real time.

2. The unmanned racing car spur gear rack dual-mode steering system according to claim 1 is characterized in that: The steering column transmission mechanism includes an upper steering column and an intermediate steering column, the output shaft of the steering wheel is fixedly connected to the first connecting end of the upper steering column, the second connecting end of the upper steering column is connected to the first connecting end of the intermediate steering column through a universal joint, and the second connecting end of the intermediate steering column is connected to the lower steering column gear through a universal joint.

3. The unmanned racing car spur gear rack dual-mode steering system according to claim 2 is characterized in that: The upper steering column is mounted on the bearing seat to provide stable support for the steering wheel.

4. The unmanned racing car spur gear rack dual-mode steering system according to claim 2 is characterized in that: The output shaft of the steering wheel is a spline shaft, and the spline shaft is connected to the first connecting end of the upper steering column through a key.

5. The unmanned racing car spur gear rack dual-mode steering system according to claim 1, characterized in that: The lower steering column gear and the rack both adopt a spur gear structure.

6. The unmanned racing car spur gear rack dual-mode steering system according to claim 1, characterized in that: It comprises a gear box bracket, the reversing gear box is mounted on the gear box bracket, and the gear box bracket is mounted on the system mounting base plate; the reversing gear box has a reversing gear transmission mechanism, and the reversing gear transmission mechanism is matched and connected with the lower steering column gear.

7. The unmanned racing car spur gear rack dual-mode steering system according to claim 6 is characterized in that: It comprises a rack housing, wherein the rack is installed in the rack housing and moves forward and backward in the rack housing under the drive of the lower steering column gear; the rack housing is installed in the gear box bracket.

8. The unmanned racing car spur gear rack dual-mode steering system according to claim 1 is characterized in that: The steering gear includes an upper bracket of a displacement sensor and a lower bracket of a displacement sensor, which are connected to form a sensor installation space, the displacement sensor is slidably installed in the sensor installation space, and the lower bracket of the displacement sensor is installed on the system installation base plate.

9. The unmanned racing car spur gear rack dual-mode steering system according to claim 1, characterized in that: The electromagnetic clutch comprises an electromagnetic clutch upper plate and an electromagnetic clutch lower plate. The electromagnetic clutch upper plate is connected with a reversing gear box, and the electromagnetic clutch lower plate is connected with a reducer.

10. The unmanned racing car spur gear rack dual-mode steering system according to claim 1, characterized in that: The reducer is fixedly mounted on the system mounting base plate through a motor bracket.

Images