Steer-by-wire system dynamic load simulation device and control method

Abstract

The invention discloses a steering-by-wire system dynamic load simulation device and a control method, the steering-by-wire system dynamic load simulation device comprises a rack, a pair of wheels connected through a main shaft, a steering-by-wire machine and a load structure, the steering-by-wire machine is used for controlling the steering of the wheels, the load structure is hoisted at the top of the rack, and a simulation table is installed on the rack through an angle adjusting structure. The simulation platform is provided with a movable plate through a moving structure, the movable plate is provided with a detachable road surface simulation pad, a wheel is placed on the road surface simulation pad, the moving structure controls the movable plate to drive the road surface simulation pad to perform friction movement relative to the wheel, and the angle adjusting structure is used for adjusting the gradient of the road surface simulation pad relative to the wheel. According to the invention, by simulating the driving state of the automobile on the road surfaces with different road surface materials, different vehicle speeds and different gradients, the scenes which can be simulated by the load simulation device can be effectively expanded, and wider test data can be conveniently obtained, so that the reliability and credibility of the test result can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of steering-by-wire system testing, and in particular to a dynamic load simulation device and a control method for a steering-by-wire system. Background Art

[0002] The steer-by-wire system replaces the traditional mechanical connection method with electronic and electrical signals and actuators, which can achieve precise control of vehicle steering, not only improving the vehicle's handling performance, but also providing a foundation for the development of autonomous driving technology. The safety and reliability of the steer-by-wire system are crucial to whether the vehicle meets functional safety. During the development process, steer-by-wire bench testing is one of the essential links, in which the function of the load simulation device is mainly to accurately simulate the load resistance that the vehicle encounters when turning during actual driving, so as to ensure the reliability and credibility of the test results.

[0003] However, the existing load simulation device has great limitations in simulating the test of automobile tires under various driving conditions such as roads of different materials, roads of different slopes, and different vehicle speeds.

[0004] To this end, we propose a dynamic load simulation device and control method for a wire-controlled steering system to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a dynamic load simulation device and control method for a steer-by-wire system to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A dynamic load simulation device for a steer-by-wire system comprises a test bench, a pair of wheels connected by a main shaft, a steer-by-wire gear and a load structure, wherein the steer-by-wire gear is used to control the steering of the wheels, the load structure is hoisted on the top of the test bench and is used to adjust the load on the wheels, a simulation table is installed on the test bench via an angle adjustment structure, a movable plate is installed on the simulation table via a movable structure, a detachable road surface simulation pad is installed on the movable plate, and the wheels are placed on the road surface simulation pad, the movable structure controls the movable plate to drive the road surface simulation pad to move relative to the wheels by friction, and keeps the wheels in a moving state, and the angle adjustment structure is used to adjust the slope of the road surface simulation pad relative to the wheels.

[0008] In a further embodiment, the material of the road simulation pad is any one of asphalt, cement, gravel, epoxy floor paint, etc.

[0009] In a further embodiment, the upper surface of the movable plate is provided with a plurality of convex strips along the moving direction of the movable plate, and the length direction of the convex strips is perpendicular to the moving direction of the movable plate, and the lower surface of the road simulation pad is provided with grooves corresponding to the convex strips.

[0010] In a further embodiment, the movable structure includes a lead screw, which is rotatably connected to the simulation table, and one end of the lead screw passing through the simulation table is connected to a motor, the external thread of the lead screw is sleeved with a screw seat, and the screw seat is fixed to the bottom of the movable plate, and a plurality of groups of straight rails and sliders parallel to the lead screw are also provided between the movable plate and the simulation table.

[0011] In a further embodiment, the load structure includes a sleeve sleeved on the outside of the main shaft, the sleeve is connected to a spring and a guide rod, and the guide rod passes through the inside of the spring, a screw is installed on the spring, a worm wheel is screwed on the outer thread of the upper end of the screw, and the outer periphery of the worm wheel is meshingly connected to a worm, and the end of the worm is connected to motor 2.

[0012] In a further embodiment, the angle adjustment structure includes a pair of hinged mechanisms installed on both sides of the bottom surface of the simulation platform. The pair of hinged mechanisms consists of a rotating sleeve, a fixed rod passing through the rotating sleeve and a bracket fixed under the fixed rod. A pair of hydraulic cylinders are installed under each bracket.

[0013] In a further embodiment, a control box and a monitoring feedback system are also included, wherein the monitoring feedback system includes a speed detector for detecting the wheel speed, a pressure detection ring for detecting the load pressure of the load structure, and a pair of distance measuring sensors for detecting the adjustment angle of the angle adjustment structure, and the monitoring feedback system, the moving structure, the load structure and the angle adjustment structure are all electrically connected to the control box.

[0014] In a further embodiment, the control box includes a signal receiving unit, a central processing unit, a motor one control output unit, a motor two control output unit, and a hydraulic cylinder control output unit. The motor one control output unit contains a frequency conversion module, and the central processing unit contains an angle conversion module.

[0015] A control method for a dynamic load simulation device of a steer-by-wire system, comprising the following steps:

[0016] By replacing the road simulation pads with different materials, the driving state of the car on the road with different materials can be simulated;

[0017] The control box controls the moving structure to drive the movable plate to move in different directions to simulate the driving state of the car moving forward or backward. At the same time, the control box controls and adjusts the moving speed of the movable plate driven by the moving structure to simulate the driving state of the car at different speeds. The speed detector feeds back the speed signal to the control box.

[0018] The control box controls the angle adjustment structure to control the rotation and tilt of the movable plate to simulate the driving state of the car on roads with different slopes, including climbing and downhill driving. The distance sensor feeds back the distance deviation signal to the control box, and the angle adjustment amount is obtained through the algorithm conversion in the control box;

[0019] The load structure is controlled by the control box to adjust the load force applied to the wheel, and the pressure detection ring feeds back the load force signal to the control box.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention simulates the driving state of a car moving forward or backward on roads with different road materials, different speeds, and different slopes, so as to effectively expand the scenarios that can be simulated by the load simulation device, thereby making the test scenarios of the load simulation device more detailed, facilitating the acquisition of more extensive test data, and thus improving the reliability and credibility of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the present invention from the left front overlooking view;

[0023] Figure 2 This is a schematic diagram of the structure of the present invention from the right front overlooking;

[0024] Figure 3 It is a schematic diagram of the structure of the present invention from the right front and viewed from above;

[0025] Figure 4 It is a schematic diagram of the load structure and wheel installation structure of the present invention;

[0026] Figure 5 It is a schematic diagram of the cross-sectional structure of the movable plate and the road simulation pad after cutting;

[0027] Figure 6 This is a framework diagram of the control method of the present invention.

[0028] In the figure: 1. test bench; 2. simulation table; 3. movable plate; 31. convex strip; 4. road simulation pad; 41. strip groove; 5. moving structure; 51. lead screw; 52. motor one; 53. screw seat; 54. straight rail; 55. slider; 56. speed detector; 6. wheel; 7. main shaft; 8. wire-controlled steering gear; 9. load structure; 91. bushing; 92. spring; 93. guide rod; 94. pressure detection ring; 95. screw; 96. worm wheel; 97. worm; 98. motor two; 10. angle adjustment structure; 101. rotating sleeve; 102. fixed rod; 103. bracket; 104. hydraulic cylinder; 105. distance sensor; 11. control box. DETAILED DESCRIPTION

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1-3 A dynamic load simulation device for a wire-controlled steering system includes a test bench 1, a pair of wheels 6 connected by a main shaft 7, a wire-controlled steering machine 8 and a load structure 9, the wire-controlled steering machine 8 is used to control the steering of the wheel 6, the load structure 9 is hoisted on the top of the test bench 1, and is used to adjust the load on the wheel 6, a simulation table 2 is installed on the test bench 1 through an angle adjustment structure 10, a movable plate 3 is installed on the simulation table 2 through a mobile structure 5, a detachable road surface simulation pad 4 is installed on the movable plate 3, and the wheel 6 is placed on the road surface simulation pad 4, so that the wheel 6 rotates and drives on the surface of the road surface simulation pad 4, the mobile structure 5 controls the movable plate 3 to drive the road surface simulation pad 4 to move relative to the wheel 6 by friction, and under the reaction of the force, the wheel 6 can be driven to rotate, the moving direction of the mobile structure 5 is different, the wheel 6 can be controlled to move forward or backward, the moving speed of the mobile structure 5 is different, the wheel 6 can be controlled to rotate at different speeds, the angle adjustment structure 10 can drive the simulation table 2 to tilt, and then be used to adjust the slope of the road surface simulation pad 4 relative to the wheel 6, so as to simulate the driving state on roads with different slopes.

[0033] See also Figure 1-2The material of the road simulation pad 4 is any one of asphalt, cement, gravel, epoxy floor paint, etc. By replacing the road simulation pad 4, the driving state of the wheel 6 on roads of different materials can be simulated. The four corners of the road simulation pad 4 are fixedly connected to the movable plate 3 by bolts.

[0034] Further, such as Figure 5 As shown, in order to prevent the poor fit between the road simulation pad 4 and the movable plate 3, which in turn causes the road simulation pad 4 to roll up when the wheel 6 rotates, a plurality of convex strips 31 are provided on the upper surface of the movable plate 3 along the moving direction of the movable plate 3, and the length direction of the convex strips 31 is perpendicular to the moving direction of the movable plate 3, and the lower surface of the road simulation pad 4 is provided with strip grooves 41 that correspond to the convex strips 31 one by one. Through the nesting cooperation of the strip grooves 41 and the convex strips 31, the road simulation pad 4 can be effectively prevented from rolling up.

[0035] See also Figure 1-3 and Figure 5 In order to facilitate the control of the movement of the movable plate 3, a moving structure 5 is provided, including a lead screw 51, both ends of which are rotatably connected to the simulation platform 2, and one end of the lead screw 51 passes through the simulation platform 2 and is connected to the output shaft of a motor 52, the main body of the motor 52 is fixed to the simulation platform 2, the lead screw 51 is externally threaded with a screw seat 53, and the screw seat 53 is fixed to the bottom of the movable plate 3, and a plurality of groups of straight rails 54 and sliders 55 parallel to the lead screw 51 are also provided between the movable plate 3 and the simulation platform 2, wherein the sliders 55 are slidably connected to the straight rails 54, the sliders 55 are fixed to the bottom of the movable plate 3, and the straight rails 54 are fixed to the inner bottom of the simulation platform 2, so as to improve the stability of the relative movement of the movable plate 3 to the simulation platform 2.

[0036] See also Figure 4 In order to facilitate the adjustment of the load on the wheel 6, a load structure 9 is provided, which includes a sleeve 91 sleeved on the outside of the main shaft 7. The main shaft 7 can rotate in the sleeve 91. The sleeve 91 is connected with a spring 92 and a guide rod 93, and the guide rod 93 passes through the inside of the spring 92. A screw 95 is installed on the spring 92. The upper end of the screw 95 passes through the top plate of the platform 1, and the outer peripheral thread of the screw 95 is screwed with a worm wheel 96. The worm wheel 96 is rotatably connected with the top plate of the platform 1. Among them, a group of sleeves 91, springs 92, guide rods 93, screws 95 and worm gears 96 are respectively arranged corresponding to the wheels 6 on both sides, with a total of two groups. A worm 97 and a motor 98 for driving the worm 97 to rotate are also rotatably installed on the top flat plate of the stand 1. The two groups of worm gears 96 are meshed and connected with the same worm 97, so that when the worm 97 rotates, the worm gear 96 is driven to rotate, and the screw 95 rises and falls under the action of the thread, so as to compress the spring 92 and adjust the load pressure.

[0037] See also Figure 1-3In order to facilitate the adjustment of road surfaces with different slopes, an angle adjustment structure 10 is provided, which includes a pair of hinged mechanisms installed on both sides of the bottom surface of the simulation platform 2. The pair of hinged mechanisms consists of a rotating sleeve 101, a fixed rod 102 passing through the rotating sleeve 101, and a bracket 103 fixed under the fixed rod 102. The rotating sleeve 101 is fixed to the bottom surface of the simulation platform 2, and a pair of hydraulic cylinders 104 are installed under each bracket 103. By controlling the synchronous extension and retraction of the hydraulic cylinders 104 under the same bracket 103, the height inconsistency at both ends of the simulation platform 2 can be adjusted to make it tilted to form a slope.

[0038] See also Figure 1-4 The simulation device also includes a control box 11 and a monitoring feedback system. The monitoring feedback system includes a speed detector 56 for detecting the speed of the wheel 6, the speed detector 56 is installed on the main shaft 7, a pressure detection ring 94 for detecting the load pressure of the load structure 9, the pressure detection ring 94 is installed at one end of the screw 95 close to the spring 92, and a pair of distance sensors 105 for detecting the adjustment angle of the angle adjustment structure 10. The pair of distance sensors 105 are respectively installed on both sides of the bottom plate of the bench 1. By detecting the distance difference between the two ends of the simulation platform 2 and the bottom plate of the bench 1, the slope angle can be calculated. The control box 11 includes a signal receiving unit, a central processing unit, a motor control output unit, a motor two control output unit, and a hydraulic cylinder control output unit. The motor one control output unit contains a frequency conversion module to facilitate voltage adjustment, thereby adjusting the speed of the motor 52. The central processing unit contains an angle conversion module. The monitoring feedback system, the mobile structure 5, the load structure 9 and the angle adjustment structure 10 are all electrically connected to the control box 11, which is convenient for the control box 11 to perform overall control.

[0039] See also Figure 6 , a control method for a dynamic load simulation device of a steer-by-wire system, comprising the following steps:

[0040] By replacing the road simulation pad 4 with different materials, the driving state of the car on the road with different materials can be simulated;

[0041] The control box 11 controls the moving structure 5 to drive the movable plate 3 to move in different directions to simulate the driving state of the car moving forward or backward. At the same time, the control box 11 controls and adjusts the moving speed of the movable plate 3 driven by the moving structure 5 to simulate the driving state of the car at different speeds. The speed detector 56 feeds back the speed signal to the control box 11;

[0042] The control box 11 controls the angle adjustment structure 10 to control the movable plate 3 to rotate and tilt, so as to simulate the driving state of the car on roads with different slopes, including climbing and downhill driving. The distance sensor 105 feeds back the distance deviation signal to the control box 11, and the angle adjustment amount is obtained through the algorithm conversion in the control box 11;

[0043] The load structure 9 is controlled by the control box 11 to adjust the load force applied to the wheel 6 , and the pressure detection ring 94 feeds back the load force signal to the control box 11 .

[0044] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0045] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A dynamic load simulation device for a steer-by-wire system, comprising a test bench (1), a pair of wheels (6) connected by a main shaft (7), a steer-by-wire machine (8) and a load structure (9), characterized in that: The wire-controlled steering machine (8) is used to control the steering of the wheel (6); the load structure (9) is hoisted on the top of the platform (1) and is used to adjust the load on the wheel (6); the platform (1) is equipped with a simulation platform (2) via an angle adjustment structure (10); the simulation platform (2) is equipped with a movable plate (3) via a movable structure (5); a detachable road surface simulation pad (4) is installed on the movable plate (3); and the wheel (6) is placed on the road surface simulation pad (4); the movable structure (5) controls the movable plate (3) to drive the road surface simulation pad (4) to move relative to the wheel (6) by friction, so as to keep the wheel (6) in a moving state; and the angle adjustment structure (10) is used to adjust the slope of the road surface simulation pad (4) relative to the wheel (6).

2. A dynamic load simulation device for a steer-by-wire system according to claim 1, characterized in that: The material of the road surface simulation pad (4) is any one of asphalt, cement, sandstone, epoxy floor paint, etc.

3. The dynamic load simulation device for a steer-by-wire system according to claim 1, characterized in that: The upper surface of the movable plate (3) is provided with a plurality of convex strips (31) along the moving direction of the movable plate (3), and the length direction of the convex strips (31) is perpendicular to the moving direction of the movable plate (3), and the lower surface of the road surface simulation pad (4) is provided with strip grooves (41) corresponding to and engaging with the convex strips (31).

4. The dynamic load simulation device for a steer-by-wire system according to claim 1, characterized in that: The movable structure (5) includes a lead screw (51) which is rotatably connected to the simulation platform (2), and one end of the lead screw (51) passing through the simulation platform (2) is connected to a motor (52). The lead screw (51) is externally threaded with a screw seat (53), and the screw seat (53) is fixed to the bottom of the movable plate (3). A plurality of straight rails (54) and sliders (55) parallel to the lead screw (51) are also provided between the movable plate (3) and the simulation platform (2).

5. The dynamic load simulation device for a steer-by-wire system according to claim 1, characterized in that: The load structure (9) comprises a shaft sleeve (91) sleeved on the outside of the main shaft (7), a spring (92) and a guide rod (93) are connected to the shaft sleeve (91), and the guide rod (93) passes through the inside of the spring (92), a screw rod (95) is installed on the spring (92), a worm wheel (96) is screwed on the outer periphery of the upper end of the screw rod (95), and a worm (97) is meshedly connected to the outer periphery of the worm wheel (96), and the end of the worm (97) is connected to the second motor (98).

6. The dynamic load simulation device for a steer-by-wire system according to claim 1, characterized in that: The angle adjustment structure (10) comprises a pair of hinged mechanisms installed on both sides of the bottom surface of the simulation platform (2), the pair of hinged mechanisms consisting of a rotating sleeve (101), a fixed rod (102) passing through the rotating sleeve (101), and a bracket (103) fixed below the fixed rod (102), and a pair of hydraulic cylinders (104) are installed under each bracket (103).

7. The dynamic load simulation device for a steer-by-wire system according to claim 1, characterized in that: The invention also comprises a control box (11) and a monitoring feedback system, wherein the monitoring feedback system comprises a rotation speed detector (56) for detecting the rotation speed of the wheel (6), a pressure detection ring (94) for detecting the load pressure of the load structure (9), and a pair of distance measuring sensors (105) for detecting the adjustment angle of the angle adjustment structure (10), and the monitoring feedback system, the mobile structure (5), the load structure (9) and the angle adjustment structure (10) are all electrically connected to the control box (11).

8. The dynamic load simulation device for a steer-by-wire system according to claim 7, characterized in that: The control box (11) comprises a signal receiving unit, a central processing unit, a motor 1 control output unit, a motor 2 control output unit, and a hydraulic cylinder control output unit; the motor 1 control output unit comprises a frequency conversion module, and the central processing unit comprises an angle conversion module.

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