An automatic driving sweeper line control steering execution system and a control method thereof

Abstract

The application discloses an automatic driving cleaning vehicle line control steering execution system, which comprises an automatic driving controller, a steering controller and a steering execution mechanism, wherein a steering column belt transmission shaft assembly and a frame plate are connected above and below a steering column mounting support in the steering execution mechanism, a bearing pressing plate connecting frame is welded on the lower surface of the frame plate, a bearing upper pressing plate is connected to the lower surface of the bearing pressing plate connecting frame, the upper part of a return spring is connected with a return spring upper connecting column, the lower part of the return spring is connected with a steering wheel mounting support, a rotary bearing is installed in a bearing lower pressing plate, the bearing lower pressing plate and the bearing upper pressing plate are connected together, the lower end surface of an elastic retaining ring for shaft is in contact with an inner steel ring of the rotary bearing, the steering wheel mounting support is welded on the lower end of a bearing mounting shaft, an interchanger is bolted in the steering wheel, and the two ends of the bearing mounting shaft are respectively fastened and connected with the two side bottoms of the steering wheel mounting support through wheel locking nuts.

Description

TECHNICAL FIELD

[0001] The application relates to an automatic driving sweeper line control steering execution system and a control method thereof, and belongs to the field of automobile steering systems. BACKGROUND

[0002] With the rapid development of automatic driving technology, the application of related technologies such as line control steering is also continuously iterated. The line control steering execution mechanism is the carrier of the realization of the line control steering technology, and the breakthrough in the development thereof is of great significance.

[0003] At present, the commonly used line control steering execution mechanism is borrowed from the steering pull rod and the steering gear of a traditional vehicle, but this scheme has the following problems when applied to an automatic driving sweeper: 1. The structure is relatively complex, and the space occupied is large, which is not conducive to the layout of the automatic driving sweeper; 2. The development requirement is focused on meeting manual driving, and the execution precision and the idle stroke cannot meet the requirements of the lateral control of the automatic driving sweeper; and 3. The unit cost is relatively high, which is not conducive to the batch use of the automatic driving sweeper.

[0004] Therefore, it is necessary to develop an automatic driving sweeper line control steering execution mechanism which is simple in structure, high in practicability, high in steering angle execution precision and low in cost, so as to accelerate the application of the line control technology to the sweeper and promote the batch commercial use of the automatic driving sweeper product. SUMMARY

[0005] The application is provided to solve the problems in the prior art, and provides an automatic driving sweeper line control steering execution system and a control method thereof, which are simple in structure, high in practicability, high in steering angle execution precision and low in cost.

[0006] The application adopts the following technical scheme: an automatic driving sweeper line control steering execution system, comprising an automatic driving controller, a steering controller and a steering execution mechanism, wherein the steering controller is connected with the steering execution mechanism through a wire harness hard wire, and the automatic driving controller is connected with the steering controller through a CAN bus;

[0007] The steering execution mechanism comprises a steering column with transmission shaft assembly, a steering column mounting bracket, a frame plate, a bearing pressing plate connecting frame, an upper bearing pressing plate, an elastic retaining ring for shaft, an upper connecting column of return spring, a return spring, a rotary bearing, a lower bearing pressing plate, a bearing mounting shaft, a wheel mounting bracket, an interchanger, a wheel locking nut, a steering wheel mounting shaft and a steering wheel.

[0008] The steering column with transmission shaft assembly is connected above the steering column mounting bracket, the frame plate is connected below the steering column mounting bracket, the bearing pressing plate connecting frame is welded on the lower surface of the frame plate, and the upper bearing pressing plate is connected to the lower surface of the bearing pressing plate connecting frame.

[0009] The upper connecting column of the return spring is connected to the side surface of the bearing upper pressing plate, the upper part of the return spring is connected with the upper connecting column of the return spring, and the lower part of the return spring is connected with the steering wheel mounting bracket;

[0010] The rotating bearing is mounted in the bearing lower pressing plate, and the bearing lower pressing plate is connected with the bearing upper pressing plate;

[0011] The upper end of the bearing mounting shaft extends to the internal space of the bearing pressing plate connecting frame after sequentially extending beyond the rotating bearing and the bearing upper pressing plate.

[0012] The shaft elastic stop ring is mounted in the clamping groove arranged on the outer side wall of the bearing mounting shaft, and the lower end surface of the shaft elastic stop ring is in contact with the inner steel ring of the rotating bearing.

[0013] The steering wheel mounting bracket is welded to the lower end of the bearing mounting shaft, and the interchanger is bolted to the steering wheel.

[0014] After the steering wheel mounting shaft is arranged in the interchanger, the two ends of the steering wheel mounting shaft are respectively fastened and connected with the two side bottoms of the steering wheel mounting bracket through the wheel locking nuts.

[0015] Further, the steering column drive shaft assembly comprises a steering motor, a steering speed reduction mechanism, a steering first universal joint, a steering upper transmission shaft, a steering second universal joint, a steering lower transmission shaft and a steering angle sensor, the steering controller and the steering motor and the steering angle sensor are connected through a wire harness hard wire, the steering speed reduction mechanism and the steering first universal joint are connected through a spline, the steering first universal joint and the steering upper transmission shaft are connected through a spline and a bolt, the steering second universal joint and the steering upper transmission shaft are connected through a spline, and the steering second universal joint and the steering lower transmission shaft are connected through a spline and a bolt.

[0016] Further, a flat key is arranged to connect the bearing mounting shaft and the steering lower transmission shaft.

[0017] Further, the interchanger comprises an interchanger left bearing, an interchanger main support and an interchanger right bearing, and the interchanger left bearing and the interchanger right bearing are fixed on the left and right sides of the interchanger main support through interference fit.

[0018] Further, a left shaft sleeve is arranged on the steering wheel mounting shaft at a position left to the interchanger left bearing, and a right shaft sleeve is arranged on the steering wheel mounting shaft at a position right to the interchanger right bearing.

[0019] Further, after the bearing upper pressing plate and the bearing lower pressing plate are fastened through bolts, the lower end surface of the bearing upper pressing plate is pressed against the outer steel ring of the rotating bearing, and the upper end surface of the bearing lower pressing plate is pressed against the outer steel ring of the rotating bearing.

[0020] Further, the wheel locking nut adopts a lock nut.

[0021] The application also adopts the following technical scheme: a control method of an automatic driving cleaning vehicle line control steering execution system, steps are as follows:

[0022] The automatic driving controller sends a steering wheel rotation angle command to the steering controller according to the calculated steering requirement, the steering controller controls the steering execution mechanism to execute after receiving the command, and feeds back the execution result to the automatic driving controller in real time;

[0023] The steering controller controls the steering motor to rotate, and the rotation is output to the steering first universal joint after being decelerated and torque-increased by the steering deceleration mechanism, and is further transmitted to the steering upper transmission shaft, the steering second universal joint and the steering lower transmission shaft, drives the bearing mounting shaft and the steering wheel to rotate, and realizes wheel steering;

[0024] The steering controller controls the steering motor to rotate, and receives the steering wheel rotation angle execution situation fed back by the rotation angle sensor in real time, and performs closed-loop control.

[0025] Further, the ratio of the steering wheel rotation angle to the steering wheel rotation angle in the steering execution mechanism is 1:1.

[0026] The application has the following beneficial effects:

[0027] (1). The steering execution mechanism has simple structure, high rotation angle execution precision, large rotation angle execution range and low cost;

[0028] (2). The steering execution mechanism can execute the steering wheel rotation angle command issued by the automatic driving controller;

[0029] (3). The steering execution mechanism has simple structure, small space occupation and is convenient to arrange on the automatic driving cleaning vehicle;

[0030] (4). The steering execution mechanism has no steering pull rod or sector gear mechanism, small steering idle stroke, high rotation angle execution precision, and can meet the lateral control requirements of the automatic driving cleaning vehicle;

[0031] (5). The steering execution mechanism directly connects the steering wheel with the steering column, can realize large-angle steering, and the wheel rotation angle can reach ±70°;

[0032] (6). The steering execution mechanism has simple part processing, low unit cost, and is convenient for batch use and popularization of the automatic driving cleaning vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is an exploded view of the steering execution mechanism.

[0034] Figure 2 The steering actuator assembly diagram of the present application.

[0035] Figure 3 The steering actuator cross-sectional view of the present application.

[0036] Figure 4 The automatic driving sweeper line control steering execution system schematic diagram of the present application. DETAILED DESCRIPTION

[0037] The present application will be further described below in conjunction with the accompanying drawings.

[0038] The automatic driving sweeper line control steering execution system of the present application, comprising an automatic driving controller 100, a steering controller 200 and a steering actuator, wherein the steering actuator comprises a steering column with transmission shaft assembly 1, a steering column mounting bracket 2, a frame plate 3, a bearing pressing plate connecting frame 4, a bearing upper pressing plate 5, a flat key 6, a shaft elastic retainer 7, a return spring upper connecting column 8, a return spring 9, a rotary bearing 10, a bearing lower pressing plate 11, a bearing mounting shaft 12, a steering wheel mounting bracket 13, an interchanger 14, a wheel locking nut 15, a right shaft sleeve 16, a steering wheel mounting shaft 17, a steering wheel 18 and a left shaft sleeve 19.

[0039] The steering column with transmission shaft assembly 1 comprises a steering motor 1-1, a steering speed reduction mechanism 1-2, a steering first universal joint 1-3, a steering upper transmission shaft 1-4, a steering second universal joint 1-5, a steering lower transmission shaft 1-6 and a rotation angle sensor 1-7, the steering speed reduction mechanism 1-2 is connected with the steering first universal joint 1-3 through spline, the steering first universal joint 1-3 is connected with the steering upper transmission shaft 1-4 through spline and bolt, the steering second universal joint 1-5 is connected with the steering upper transmission shaft 1-4 through spline, and the steering second universal joint 1-5 is connected with the steering lower transmission shaft 1-6 through spline and bolt.

[0040] The steering column with transmission shaft assembly 1 is bolted above the steering column mounting bracket 2, the frame plate 3 is bolted below the steering column mounting bracket 2, and the bearing pressing plate connecting frame 4 is welded on the lower surface of the frame plate 3. The bearing upper pressing plate 5 is bolted on the lower surface of the bearing pressing plate connecting frame 4.

[0041] The return spring upper connecting column 8 is threadedly connected on the side surface of the bearing upper pressing plate 5, the upper part of the return spring 9 is connected with the return spring upper connecting column 8, and the lower part of the return spring 9 is connected with the steering wheel mounting bracket 13. After the return spring 9 is connected with the return spring upper connecting column 8 and the steering wheel mounting bracket 13, it should have a certain pre-tightening force, which can make the steering wheel 18 have a suitable return torque to ensure that the steering wheel 18 does not deviate when driving on a horizontal road.

[0042] After the rotating bearing 10 is installed in the bearing lower pressing plate 11, the bearing lower pressing plate 11 and the bearing upper pressing plate 5 are connected together by bolts. The inner end face of the bearing upper pressing plate 5 and the outer end face of the bearing lower pressing plate 11 are in clearance fit. After the bearing upper pressing plate 5 and the bearing lower pressing plate 11 are fastened by bolts, the lower end face of the bearing upper pressing plate 5 and the outer ring of the rotating bearing 10, and the upper end face of the bearing lower pressing plate 11 and the outer ring of the rotating bearing 10 are pressed tightly, respectively. The rotating bearing 10 is selected from a bearing type that simultaneously has axial force and radial force bearing.

[0043] After the bearing mounting shaft 12 is inserted through the bearing lower pressing plate 11 and connected with the rotating bearing 10 in interference fit, the upper end of the bearing mounting shaft 12 extends beyond the rotating bearing 10 and the bearing upper pressing plate 5 in turn, and extends into the internal space of the bearing pressing plate connecting frame 4.

[0044] The shaft elastic retainer 7 is installed in the clamping groove provided on the outer side wall of the bearing mounting shaft 12, and the lower end face of the shaft elastic retainer 7 is in contact with the inner ring of the rotating bearing 10. The bearing mounting shaft 12 is connected with the steering lower transmission shaft 1-6 through a flat key 6.

[0045] The steering wheel mounting bracket 13 is welded on the lower end of the bearing mounting shaft 12, and the interchanger 14 is bolted in the steering wheel 18.

[0046] The interchanger 14 includes an interchanger left bearing 14-1, an interchanger main bracket 14-2, and an interchanger right bearing 14-3. The interchanger left bearing 14-1 and the interchanger right bearing 14-3 are fixed on the left and right sides of the interchanger main bracket 14-2 through interference fit.

[0047] The two ends of the steering wheel mounting shaft 17 pass through the interchanger left bearing 14-1, the left shaft sleeve 16, and the interchanger right bearing 14-3, the right shaft sleeve 19, and are fastened and connected with the two side bottoms of the steering wheel mounting bracket 13 through the wheel locking nut 15. After the wheel locking nut 15 is fastened, the right shaft sleeve 16 and the left shaft sleeve 19 are pressed against the inner end face of the steering wheel mounting bracket 13, and the right shaft sleeve 16 and the left shaft sleeve 19 are pressed against the inner rings of the interchanger left bearing 14-1 and the interchanger right bearing 14-3. The wheel locking nut 15 is a lock nut that prevents loosening.

[0048] The steering controller 200 is connected with the steering motor 1-1 and the angle sensor 1-7 through a wire harness hard wire. The automatic driving controller 100 is connected with the steering controller 200 through a CAN bus.

[0049] The control process of the automatic driving cleaning vehicle line control steering execution system of the present application is as follows:

[0050] The automatic driving controller 100 sends a steering wheel turning angle command to the steering controller 200 according to the calculated steering demand, and the steering controller 200 controls the steering actuator to execute and feeds back the execution result to the automatic driving controller 100 in real time.

[0051] The steering controller 200 controls the steering motor 1-1 to rotate, and the rotation is output to the steering first universal joint 1-3 after being decelerated and torque-increased by the steering deceleration mechanism 1-2, and is further transmitted to the steering upper transmission shaft 1-4, the steering second universal joint 1-5 and the steering lower transmission shaft 1-6, to drive the bearing mounting shaft 12 and the steering wheel 18 to rotate, thereby realizing wheel steering.

[0052] The steering controller 200 controls the steering motor 1-1 to rotate, and receives the steering wheel turning angle execution feedback from the turning angle sensor 1-7 in real time, and performs closed-loop control.

[0053] After the bearing upper pressing plate 5 and the bearing lower pressing plate 11 are fastened by bolts, the lower end surface of the bearing upper pressing plate 5 and the outer ring of the rotating bearing 10 are pressed tightly, and the upper end surface of the bearing lower pressing plate 11 and the outer ring of the rotating bearing 10 are pressed tightly, so as to withstand and offset the upward impact force of the rotating bearing 10 during vehicle driving, and prevent the rotating bearing 10 from moving up and down.

[0054] After the shaft elastic retainer 7 is installed into the clamping groove above the bearing mounting shaft 12, the lower end surface of the shaft elastic retainer 7 contacts the inner ring of the rotating bearing 10, so as to avoid the problem of the bearing mounting shaft 12 falling off due to long-term use of the vehicle.

[0055] The bearing mounting shaft 12 and the steering lower transmission shaft 1-6 are connected by the flat key 6, and the inner hole mounting surface of the bearing mounting shaft 12 and the outer circle mounting surface of the steering lower transmission shaft 1-6 are gap-fitted instead of spline-fitted, so as to reduce the machining cost of the parts.

[0056] The ratio of the steering wheel turning angle to the steering wheel turning angle in the steering actuator is 1:1, which can reduce the requirement for the steering wheel turning angle range of the steering column shaft assembly 1, and can also realize large-angle turning.

[0057] The above is only the preferred embodiment of the present application, and it should be pointed out that those skilled in the art can make some improvements without departing from the principles of the present application, and these improvements should also be regarded as the protection scope of the present application.

Claims

1. A drive-by-wire steering system for an autonomous sweeper, characterized in that: It includes an automatic driving controller (100), a steering controller (200), and a steering actuator. The steering controller (200) and the steering actuator are connected by a wiring harness and hardwired. The automatic driving controller (100) and the steering controller (200) are connected by a CAN bus. The steering actuator includes a steering column belt drive shaft assembly (1), a steering column mounting bracket (2), a frame plate (3), a bearing pressure plate connecting bracket (4), an upper bearing pressure plate (5), an axle elastic retaining ring (7), a return spring upper connecting column (8), a return spring (9), a swivel bearing (10), a lower bearing pressure plate (11), a bearing mounting shaft (12), a steering wheel mounting bracket (13), an interchangeable part (14), a wheel lock nut (15), a steering wheel mounting shaft (17), and a steering wheel (18). The steering column belt drive shaft assembly (1) is connected above the steering column mounting bracket (2), the frame plate (3) is connected below the steering column mounting bracket (2), the bearing pressure plate connecting bracket (4) is welded to the lower surface of the frame plate (3), and the upper bearing pressure plate (5) is connected to the lower surface of the bearing pressure plate connecting bracket (4). The upper connecting post (8) of the return spring is connected to the side surface of the upper pressure plate (5) of the bearing, the upper part of the return spring (9) is connected to the upper connecting post (8), and the lower part of the return spring (9) is connected to the steering wheel mounting bracket (13). After the rotary bearing (10) is installed in the lower bearing plate (11), the lower bearing plate (11) is connected to the upper bearing plate (5); The upper end of the bearing mounting shaft (12) extends beyond the rotary bearing (10) and the upper bearing pressure plate (5) in sequence, and then extends into the internal space of the bearing pressure plate connecting frame (4); The shaft elastic retaining ring (7) is installed in a slot provided on the outer side wall of the bearing mounting shaft (12), and the lower end face of the shaft elastic retaining ring (7) is in contact with the inner steel ring of the rotary bearing (10); The steering wheel mounting bracket (13) is welded to the lower end of the bearing mounting shaft (12), and the interchangeable device (14) is bolted to the steering wheel (18); After the steering wheel mounting shaft (17) is inserted into the interchanger (14), its two ends are respectively fastened to the bottom of the two sides of the steering wheel mounting bracket (13) by wheel locking nuts (15); The steering column with drive shaft assembly (1) includes a steering motor (1-1), a steering reduction mechanism (1-2), a first steering universal joint (1-3), an upper steering drive shaft (1-4), a second steering universal joint (1-5), a lower steering drive shaft (1-6), and a steering angle sensor (1-7). The steering controller (200) is connected to the steering motor (1-1) and the steering angle sensor (1-7) via a wiring harness. The steering reduction mechanism (1-2) is connected to the first steering universal joint (1-3) via a spline. The first steering universal joint (1-3) is connected to the upper steering drive shaft (1-4) via a spline and bolts. The second steering universal joint (1-5) is connected to the upper steering drive shaft (1-4) via a spline. The second steering universal joint (1-5) is connected to the lower steering drive shaft (1-6) via a spline and bolts. It also includes a flat key (6) that connects the bearing mounting shaft (12) to the steering lower drive shaft (1-6).

2. The drive-by-wire steering system for an automated sweeper as described in claim 1, characterized in that: The interchanger (14) includes an interchanger left bearing (14-1), an interchanger main support (14-2), and an interchanger right bearing (14-3). The interchanger left bearing (14-1) and the interchanger right bearing (14-3) are fixed to the left and right sides of the interchanger main support (14-2) by interference fit.

3. The drive-by-wire steering system for an autonomous sweeper as described in claim 2, characterized in that: A left bushing (16) is installed on the steering wheel mounting shaft (17) at the position to the left of the interchanger left bearing (14-1), and a right bushing (19) is installed on the steering wheel mounting shaft (17) at the position to the right of the interchanger right bearing (14-3).

4. The drive-by-wire steering system for an automated sweeper as described in claim 1, characterized in that: After the upper bearing pressure plate (5) and the lower bearing pressure plate (11) are fastened with bolts, the lower end face of the upper bearing pressure plate (5) presses against the outer steel ring of the rotating bearing (10), and the upper end face of the lower bearing pressure plate (11) presses against the outer steel ring of the rotating bearing (10).

5. The drive-by-wire steering system for an automated sweeper as described in claim 1, characterized in that: The wheel locking nut (15) is an anti-loosening locking nut.

6. A control method for a drive-by-wire steering system for an automated sweeper as described in any one of claims 1-5, characterized in that: The steps are as follows: The automatic driving controller (100) sends a steering wheel angle command to the steering controller (200) based on the calculated steering requirements. After receiving the command, the steering controller (200) controls the steering actuator and feeds back the execution result to the automatic driving controller (100) in real time. The steering controller (200) controls the steering motor (1-1) to rotate. This rotation is decelerated and amplified by the steering reduction mechanism (1-2) and then output to the first steering universal joint (1-3), and transmitted to the upper steering drive shaft (1-4), the second steering universal joint (1-5), and the lower steering drive shaft (1-6), which drive the bearing mounting shaft (12) and the steering wheel (18) to rotate, thereby realizing wheel steering. The steering controller (200) controls the steering motor (1-1) to rotate and receives feedback from the steering angle sensor (1-7) in real time on the steering wheel angle execution status, and performs closed-loop control.

7. The control method for the drive-by-wire steering system of the autonomous sweeper as described in claim 6, characterized in that: The ratio of the steering wheel angle to the steering wheel angle in the steering actuator is 1:1.

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