Calibration system for braking performance tester based on tangential acceleration

Abstract

The utility model discloses a kind of brake performance tester calibration systems based on tangential acceleration, comprising: controller, brake pedal, rotary table and be used for driving the driving device of the rotary table, the rotary table is equipped with first installation platform, first brake interface, the first installation platform is used to install the acceleration sensor to be calibrated, the first brake interface is used to be connected with host computer to be calibrated, the signal of the brake pedal is received in the first brake interface, the controller is connected with the driving device, the controller is equipped with second brake interface for being connected with brake pedal. Directly simulate straight-line travel distance, realize calibration in room.

Description

Technical Field

[0001] This utility model relates to the field of metrology and verification, and in particular to a calibration system for a braking performance tester based on tangential acceleration. Background Technology

[0002] A portable brake performance tester is an instrument used to measure the braking performance of motor vehicles. By recording the time history of deceleration values ​​during vehicle braking, it calculates the speed and distance, and then calculates the average deceleration (MFDD) and braking coordination time. It generally consists of an acceleration sensor, a main unit, brake pedal contact switches, and a miniature printer, with the acceleration sensor being its main component.

[0003] The calibration of portable brake performance testers is divided into static calibration and dynamic calibration.

[0004] The principle of static calibration is to simulate braking deceleration through gravity, precisely control the angle of the tilting platform, and utilize the angle-acceleration relationship. (g is the acceleration due to gravity, θ is the angle of the flipping platform) Calibration is achieved by generating different decelerations. This method is technically mature and widely used.

[0005] Dynamic calibration is divided into the vehicle speedometer method and the indoor dynamic calibration device method. The vehicle speedometer method typically involves mounting a non-contact speedometer and the portable brake performance tester on a test vehicle, connecting their pedal switches, and fixing them to the vehicle's brake pedal. When the test vehicle accelerates to a certain speed (approximately 30 km / h or 50 km / h), the brake pedal is depressed, triggering the speedometer and the tester to begin measurement. After the test vehicle comes to a complete stop, the MFDD values ​​of both are compared. To ensure safety, this method requires testing on a relatively straight and open road, and simultaneous activation of the pedal switches on both the speedometer and the tester is necessary for accurate measurements. In actual measurements, the size and specifications of the pedal switches on different tester models vary, making it difficult to securely install them on the test vehicle's brake pedal. Often, the tester's pedal switch is activated only one or two seconds after the brake pedal is depressed, or even fails to activate at all, resulting in numerous retests and poor stability.

[0006] There are several types of indoor dynamic calibration devices. One type is a linear track calibration device, which involves mounting the instrument to be calibrated on a movable platform and having a motor drive the platform to simulate the braking process of a motor vehicle on a guide rail. This device has high construction requirements; the guide rail is generally 25-30 meters long, occupying a large area. Furthermore, the braking process is completed within a limited distance, limiting the reduction in size and weight of the movable platform. The acceleration and deceleration require high control capabilities from the drive system, resulting in a large overall investment. Another type utilizes a rotating platform, similar to static calibration, to continuously change the orientation of the instrument's sensors, thereby altering the acceleration and simulating the braking process curve. Additionally, there is a method using the centripetal acceleration principle, where the instrument's sensors are fixed on a turntable with their orientation aligned radially with the turntable. Changing the rotation speed achieves acceleration changes, simulating the braking process curve. The latter two methods are essentially not much different from static calibration and cannot realistically simulate the linear braking process of a motor vehicle. Summary of the Invention

[0007] The purpose of this invention is to provide a braking performance testing instrument calibration system based on tangential acceleration, which can directly simulate driving distance and achieve indoor calibration.

[0008] A calibration system for a braking performance tester based on tangential acceleration includes: a controller, a brake pedal, a turntable, and a drive device for driving the turntable. The turntable is provided with a first mounting platform and a first braking interface. The first mounting platform is used to mount an acceleration sensor to be calibrated. The first braking interface is used to connect to the host machine to be calibrated and to receive signals from the brake pedal. The controller is connected to the drive device and is provided with a second braking interface for connecting to the brake pedal.

[0009] In one embodiment, the turntable is provided with a slide rail and a slide block, the slide block is slidably engaged with the slide rail, the slide block is provided with a first mounting platform, and when the slide block slides on the slide rail, the distance of the first mounting platform relative to the rotation axis of the turntable changes.

[0010] In one embodiment, the first mounting platform includes a concave groove, the sidewall of which is provided with a first screw hole and a first fastener, the first fastener being screwed into the first screw hole.

[0011] In one embodiment, the first mounting platform is movably connected to the slide, and the slide is provided with a second screw hole and a second fastener, the second fastener being screwed into the second screw hole; or, the first mounting platform is provided with a second screw hole and a second fastener, the second fastener being screwed into the second screw hole; when the second fastener is tightened, the first mounting platform can be positioned on the slide.

[0012] In one embodiment, the turntable is provided with a marker line of a specified diameter; or, the turntable is provided with a tangential marker line at a specified diameter.

[0013] In one embodiment, the edge of the turntable has a tangential straight edge as the tangential marker line.

[0014] In one embodiment, the turntable includes a table surface and a rotating shaft, the rotating shaft being equipped with a photoelectric encoder, and the photoelectric encoder being connected to the controller.

[0015] In one embodiment, the turntable is provided with a second mounting platform.

[0016] In one embodiment, the first brake interface is provided with a first wireless connection module, and the brake pedal is provided with a second wireless connection module, the first wireless connection module cooperating with the second connection module.

[0017] In one embodiment, the surface of the turntable is provided with several sets of mounting holes, each set of mounting holes including two or more mounting holes, and the slide rail is mounted on one set of the mounting holes by bolts.

[0018] Compared with the prior art, the advantages of the braking performance testing instrument calibration system and method based on tangential acceleration of this utility model are as follows: 1. This utility model provides a method for dynamic calibration that can be performed indoors. Compared to existing technologies that rely on sampling calculations, this method directly simulates and measures the travel distance during braking by rotating a turntable. Based on the rotational speed generated by the turntable and combined with the turntable radius, the standard linear velocity, standard acceleration, and standard travel distance of the turntable can be calculated. The acceleration change is controlled by a motor drive to realistically simulate the entire process of linear braking of a motor vehicle, outputting a standard average deceleration (MFDD) and simultaneously calculating the braking coordination time.

[0019] 2. The first braking interface is equipped with a wireless connection component. The first braking interface is connected to the main unit to receive the braking signal from the brake pedal. The first braking interface, the acceleration sensor and the main unit rotate with the turntable. By adopting a wireless connection, the first braking interface can receive the braking signal from the brake pedal and transmit the signal to the main unit. The main unit synchronously records the value detected by the acceleration sensor during the braking process for calibration. This does not interfere with the acceleration sensor and the main unit rotating with the turntable, and has good durability.

[0020] The present invention will become clearer from the following description and in conjunction with the accompanying drawings, which are used to explain the embodiments of the present invention. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of the calibration system for braking performance testing instrument based on tangential acceleration in use according to an embodiment of this utility model; Figure 2 This is a schematic diagram of the overall structure of the braking performance tester calibration system based on tangential acceleration according to an embodiment of this utility model; Figure 3 This is a cross-sectional structural schematic diagram of the calibration system for a braking performance tester based on tangential acceleration according to an embodiment of this utility model; Figure 4 This is a schematic diagram of the structure of the first mounting platform, slide, and slide rail on which the acceleration sensor is installed in an embodiment of this utility model; Figure 5 This is a schematic diagram of the first mounting platform, slide, and slide rail without an accelerometer installed in this embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the second mounting platform in this embodiment of the present invention; Figure 7 This is a plan view of the turntable surface in an embodiment of this utility model.

[0023] Among them, 1. Controller, 2. Turntable, 3. Drive device, 4. First mounting platform, 5. Accelerometer, 6. Main unit, 7. Slide rail, 8. Slide block, 9. Second mounting platform, 10. Concave groove, 11. First screw hole, 12. First fastener, 13. Second screw hole, 14. Second fastener, 15. Table surface, 16. Rotating shaft, 17. Photoelectric encoder, 18. Mounting hole, 19. Second brake interface, 20. Brake pedal, 21. Adjusting foot, 22. Through hole, 23. Tangential marking line. Detailed Implementation

[0024] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0025] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "test" and "display" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" 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 an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] like Figures 1 to 7 As shown in the figure, this embodiment of a braking performance tester calibration system based on tangential acceleration is characterized by comprising: a controller 1, a brake pedal 20, a turntable 2, and a drive device 3 for driving the turntable 2. The turntable 2 is provided with a first mounting platform 4 and a first braking interface. The first mounting platform 4 is used to mount the acceleration sensor 5 to be calibrated. The first braking interface is used to connect to the host 6 to be calibrated and to receive signals from the brake pedal 20. The controller 1 is connected to the drive device 3 and is provided with a second braking interface 19 for connecting to the brake pedal 20.

[0028] The first braking interface is used to connect to the host 6. When the brake pedal 20 is pressed, the host 6 receives a braking start signal through the first braking interface and then synchronously acquires the signal from the acceleration sensor 5 during braking. In this embodiment, the first braking interface is a wireless connection, which is simple in structure, durable, and has low wear and tear, and does not interfere with the rotation of the acceleration sensor 5 and the host 6 on the turntable 2. However, it is not limited to this embodiment; a rotary connector can also be used, and a physical wire can be used for connection. The term "interface" in this document includes, but is not limited to, various types of connectors, plugs, sockets, wireless modules, etc., used for connection, as long as a connection can be achieved. In this embodiment, the first braking interface is not shown in the figure. The first braking interface is a plug-and-play plug, similar to the USB plug that goes into a desktop computer case with a wireless mouse.

[0029] Preferably, the first braking interface is equipped with a first wireless connection module, and the brake pedal 20 is equipped with a second wireless connection module, which cooperate with the second connection module. The first braking interface is connected to the host 6 to receive the braking signal from the brake pedal 20. The first braking interface, the acceleration sensor 5, and the host 6 rotate with the turntable 2. Through wireless connection, the first braking interface can receive the braking signal from the brake pedal 20 and transmit the signal to the host 6. The host 6 synchronously records the value detected by the acceleration sensor 5 during braking for calibration. The brake pedal 20 is used to trigger automatic braking. When the brake pedal 20 is pressed, the controller 1 receives a signal through the second braking interface 19 and simultaneously triggers the portable braking performance tester under test and the turntable 2 to brake until the turntable 2 comes to a complete stop. Calibration can be achieved by comparing the average deceleration and braking coordination time displayed by the portable braking performance tester with the standard values ​​of the turntable 2.

[0030] The turntable 2 is equipped with a slide rail 7 and a slide block 8, which slide in slidable engagement with the slide rail 7. The slide block 8 has a first mounting platform 4. When the slide block 8 slides on the slide rail 7, the distance of the first mounting platform 4 relative to the rotation axis of the turntable 2 changes. The first mounting platform 4 is used to mount the accelerometer 5 to be calibrated. By sliding the slide block 8 on the slide rail 7, the position of the first mounting platform 4 relative to the rotation axis can be adjusted, thereby adjusting the rotation radius of the accelerometer 5 to adapt to different test requirements. Alternatively, when calibrating accelerometers 5 of different specifications, the position of the slide block 8 on the slide rail 7 can be adjusted so that the sensing direction of the corresponding accelerometer 5 is aligned with the tangential mark line 23 of a specified diameter, thus expanding the applicability of the calibration device. In this embodiment, the slide rail 7 is arranged along the radial direction of the turntable 2, which facilitates adjustment.

[0031] like Figure 4 , 5 As shown, the first mounting platform 4 includes a concave groove 10. The side wall of the concave groove 10 is provided with a first screw hole 11 and a first fastener 12. The first fastener 12 is screwed into the first screw hole 11. The acceleration sensor 5 is placed in the concave groove 10, and the position of the acceleration sensor 5 is adjusted so that its measurement direction is tangential to the rotation of the turntable 2. The first fastener 12 is tightened to secure the acceleration sensor 5, thus realizing the installation of the acceleration sensor 5 on the first mounting platform 4.

[0032] The first mounting platform 4 is movably connected to the slide 8. The slide 8 is provided with a second screw hole 13 and a second fastener 14, with the second fastener 14 screwed into the second screw hole 13; or, the first mounting platform 4 is provided with a second screw hole 13 and a second fastener 14, with the second fastener 14 screwed into the second screw hole 13; when the second fastener 14 is tightened, the first mounting platform 4 can be positioned on the slide 8. In this embodiment, the concave groove 10 and the slide 8 are rotatably engaged, and the lower part of the concave groove 10 and the slide 8 are rotatably engaged through a damping shaft. The side wall of the slide 8 is provided with a second screw hole 13, and tightening the second fastener 14 can fix the position of the slide 8. However, it is not limited to this embodiment; the slide 8 and the concave groove 10 can also be connected through a universal joint, which can adjust not only the horizontal rotation of the concave groove 10 but also the levelness of the concave groove 10.

[0033] Preferably, the turntable 2 is provided with a marker line of a specified diameter; or, the turntable 2 is provided with a tangential marker line 23 at a specified diameter. By aligning the sensing direction of the acceleration sensor 5 with the tangential direction of the marker line at the specified diameter or aligning it with the tangential marker line 23, it can be known that the acceleration sensor 5 rotates according to the specified diameter r. The value of this diameter r can be used to calculate the standard linear velocity and the standard travel distance.

[0034] like Figure 7 As shown, in this embodiment, the edge of the turntable 2 is provided with a tangential straight edge as a tangential marker line 23. Based on the recognition characteristics of the human eye, setting a marker line at the edge makes it easier for the operator to align. In this embodiment, the edge of the turntable 2 near the first mounting platform 4 is at a specified diameter, where the diameter of the turntable 2 edge is a fixed value r. A tangential straight edge is provided on the edge of the turntable 2 as a tangential marker line for calculating standard linear velocity and standard travel distance.

[0035] like Figure 3 As shown, the turntable 2 includes a table surface 15 and a rotating shaft 16. The rotating shaft 16 is equipped with a photoelectric encoder 17, which is connected to the controller 1. The rotational speed of the turntable 2 is obtained through the photoelectric encoder 17.

[0036] like Figure 1 , 7 As shown, a second mounting platform 9 is provided on the turntable 2. The second mounting platform 9 is used to mount the host 6 to be tested. In this embodiment, the second mounting platform 9 is located in the center of the turntable 2 to facilitate the connection between the host 6 and the acceleration sensor 5. The second mounting platform 9 has a groove, and the side wall of the groove has screw holes and bolts. The host 6 is tightened by screwing the bolts into the screw holes.

[0037] The surface of the turntable 2 is provided with several sets of mounting holes 18, each set including two or more mounting holes 18. The slide rail 7 is mounted on one set of mounting holes 18 by bolts. In this embodiment, a total of eight sets of mounting holes 18 are provided, each set of mounting holes 18 is distributed radially, and the sets of mounting holes 18 are radially and centrally symmetrically distributed on the table surface 15 of the turntable 2. The slide rail 7 is elongated, and several through holes 22 for installation are also provided in the elongated direction. Bolts can be screwed into the mounting holes 18 through the through holes 22 to realize the installation of the slide rail 7 on the turntable 2. The first mounting platform 4 is installed in multiple sets of mounting holes 18, which can simultaneously calibrate multiple acceleration sensors 5.

[0038] The bottom of the turntable 2 is equipped with a leveling foot 21. The leveling foot 21 is used to adjust the turntable 2 to be level, so that the accelerometer sensor 5 to be calibrated can rotate on a horizontal plane, reducing errors.

[0039] Generally, a braking performance tester consists of an acceleration sensor 5, a main unit 6, a brake pedal 20 with a contact switch interface, and a micro printer, etc. Its main function is to detect vehicle acceleration. When using the braking performance tester calibration system based on tangential acceleration in this embodiment for calibration: Step S1: Adjust the leveling feet 21 to make the plane of the turntable 2 level; Step S2: Loosen the first fastener 12 and install the acceleration sensor 5 onto the first mounting platform 4. Loosen the second fastener 14 and slide the slide block 8 onto the slide rail 7. Adjust the acceleration sensor 5 to be horizontal and align its sensing direction with the tangential mark line 23 on the edge of the turntable 2. Tighten the first fastener 12 and the second fastener 14. Install the main unit 6 onto the second mounting platform 9. Connect the main unit 6 and the acceleration sensor 5. Connect the first brake interface to the main unit 6. Debug the connection between the first brake interface and the brake pedal 20 to ensure smooth connection. Step S3: Start the drive unit 3 to rotate the turntable 2, accelerate the turntable 2 to the initial speed required for the test (30km / h or 50km / h), and maintain a constant speed. Press down the brake pedal 20, simultaneously triggering the braking of the test instrument and the turntable 2 until the turntable 2 comes to a complete stop. The controller 1 records the rotational speed and time changes of the turntable 2. The standard linear velocity v is obtained based on the rotational speed n of the turntable 2 and the installation radius r of the acceleration sensor 5. The standard travel distance S is obtained based on the rotational speed n and the rotational time t. The standard MFDD is calculated using the following formula. The test instrument records the speed, distance, MFDD, and braking coordination time values ​​measured by the acceleration sensor 5.

[0040] Specifically, according to the testing standard in Clause 7.10.2.2 of GB 7258-2017 "Technical Conditions for Safe Operation of Motor Vehicles", the average deceleration MFDD fully generated by a vehicle when it is suddenly braked at a specified initial speed is as follows:

[0041] In the formula, MFDD - Mean deceleration at full power, measured in meters per second squared (m / s²). ); - Initial braking speed of the test vehicle, in kilometers per hour (km / h); - 0.8 Test vehicle speed, in kilometers per hour (km / h); - 0.1 Test vehicle speed, in kilometers per hour (km / h); - Test vehicle speed from arrive The distance traveled between vehicles, in meters (m); - Test vehicle speed from arrive The distance traveled between vehicles, in meters (m).

[0042] Calibration is achieved by comparing the average deceleration and braking coordination time displayed by the braking performance tester to be calibrated with the standard values ​​of turntable 2.

[0043] The present invention has been described above in conjunction with the preferred embodiments, but the present invention is not limited to the embodiments disclosed above, but should cover various modifications and equivalent combinations made in accordance with the essence of the present invention.

Claims

1. A calibration system for a braking performance testing instrument based on tangential acceleration, characterized in that, include: The system includes a controller, a brake pedal, a turntable, and a drive device for driving the turntable. The turntable has a first mounting platform and a first brake interface. The first mounting platform is used to mount an acceleration sensor to be calibrated. The first brake interface is used to connect to the host computer to be calibrated and to receive signals from the brake pedal. The controller is connected to the drive device and has a second brake interface for connecting to the brake pedal.

2. The calibration system for a braking performance tester based on tangential acceleration according to claim 1, characterized in that, The turntable is provided with a slide rail and a slide block. The slide block is slidably engaged with the slide rail. The slide block is provided with a first mounting platform. When the slide block slides on the slide rail, the distance of the first mounting platform relative to the rotation axis of the turntable changes.

3. The calibration system for a braking performance tester based on tangential acceleration according to claim 2, characterized in that, The first mounting platform includes a concave groove, and the side wall of the concave groove is provided with a first screw hole and a first fastener, the first fastener being screwed into the first screw hole.

4. The calibration system for a braking performance tester based on tangential acceleration according to claim 2, characterized in that, The first mounting platform is movably connected to the slide block, and the slide block is provided with a second screw hole and a second fastener, the second fastener being screwed into the second screw hole; or, the first mounting platform is provided with a second screw hole and a second fastener, the second fastener being screwed into the second screw hole; when the second fastener is tightened, the first mounting platform can be positioned on the slide block.

5. A calibration system for a braking performance tester based on tangential acceleration according to claim 1, characterized in that, The turntable is provided with a marker line of a specified diameter; or, the turntable is provided with a tangential marker line at a specified diameter.

6. The calibration system for a braking performance tester based on tangential acceleration according to claim 5, characterized in that, The turntable has a tangential straight edge along its edge as a tangential marker line.

7. The calibration system for a braking performance tester based on tangential acceleration according to claim 1, characterized in that, The turntable includes a table surface and a rotating shaft. The rotating shaft is equipped with a photoelectric encoder, which is connected to the controller.

8. The calibration system for a braking performance tester based on tangential acceleration according to claim 1, characterized in that, The turntable is equipped with a second mounting platform.

9. A calibration system for a braking performance tester based on tangential acceleration according to claim 1, characterized in that, The first brake interface is provided with a first wireless connection module, and the brake pedal is provided with a second wireless connection module. The first wireless connection module and the second wireless connection module cooperate with each other.

10. A calibration system for a braking performance tester based on tangential acceleration according to claim 2, characterized in that, The surface of the turntable is provided with several sets of mounting holes, each set of mounting holes including two or more mounting holes, and the slide rail is mounted on one set of mounting holes by bolts.

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