Indoor calibration method for speed measuring device of motor vehicle exhaust remote control detector

Abstract

The invention relates to the technical field of calibration of speed measuring devices, and provides an indoor calibration method for a speed measuring device of a motor vehicle exhaust remote control detector, which comprises the following steps: S1, a preparation stage: installing a calibration device which comprises a rack, a driving mechanism, a control mechanism and a shielding object, the driving mechanism is used for driving the shielding object to do linear motion along the rack, and the control mechanism is used for setting parameters of linear motion of the shielding object; s2, an initialization stage: stopping a shielding object at an initial position; s3, installing a speed measuring device; s4, calibrating the speed; s5, carrying out acceleration calibration; and S6, completing calibration of the speed measuring device. The technical scheme of the invention has the beneficial effects or advantages that the test vehicle does not need to be manually driven, the shielding object is used for simulating the driving condition of the test vehicle, the device accurately and stably controls the motion state of the shielding object, and the efficiency of calibrating the speed measuring device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of calibration of speed measurement devices, and particularly to an indoor calibration method for a speed measurement device of a motor vehicle exhaust remote detector. Background Art

[0002] A motor vehicle exhaust remote detector is an important device for detecting motor vehicle exhaust, and is widely used by environmental supervision departments as the basis for environmental monitoring and administrative penalties. A motor vehicle exhaust remote detector is a measurement system that uses remote sensing methods to detect pollutants emitted by motor vehicles traveling within a specified speed range under certain meteorological conditions and road gradients. Its working principle: The transmitting end of the remote detector host emits a light beam. When a motor vehicle passes by, the exhaust gas interferes with the light beam, and the characteristics of the light such as the spectrum and intensity received by the receiving end will change. This change can reflect the change in the concentration of the measured pollutant or the opacity. A motor vehicle exhaust remote detector mainly consists of an emission pollutant measurement device, a speed measurement device, a road gradient measurement device, a meteorological parameter measurement device, a vehicle license plate recognition system, a control and management computer system, etc. Among them, the speed measurement device is used to measure the driving speed of a motor vehicle. The measurement principle is based on the fast speed measurement principle of the light-shielding method, that is, by setting two photoelectric sensors with equal distances on the road. When the vehicle passes through these two photoelectric sensors, the two photoelectric sensors will respectively record two time points. The speed measurement device calculates the distance and time traveled by the vehicle between these two time points, and thus calculates the speed of the vehicle.

[0003] As measuring instruments, the emission pollutant measurement device, the speed measurement device, the road gradient measurement device, and the meteorological parameter measurement device must be calibrated by a metrological technical institution before they can be used as the technical support for supervision. Currently, according to the national metrological technical regulation JJF 1835-2020, the calibration method for the speed measurement device is to use the standard speedometer method. The standard speedometer is installed on the test vehicle, and according to the speed points to be calibrated, the test vehicle passes through the monitoring area of the speed measurement device of the motor vehicle exhaust remote detector at a constant speed according to the speed value of the speed point to be calibrated. The standard speedometer measures and displays the actual speed value of the test vehicle when passing through the monitoring area, and at the same time the speed measurement device measures the speed of the test vehicle. By comparing the measured speed values of the speed measurement device and the standard speedometer located on the test vehicle, the speed indication error of the speed measurement device is obtained, that is, the speed measurement device of the motor vehicle exhaust remote detector is calibrated by using the standard speedometer located on the test vehicle.

[0004] The following problems exist in the current standard speedometer method: (1) The test vehicle is controlled by the driver. It is very difficult to ensure that the test vehicle is traveling at a constant speed when passing through the monitoring area of the speed measurement device. Therefore, when calibrating, it is very difficult to make a one-to-one correspondence between the speed measured by the speed measurement device and the speed measured by the standard speedometer, and it is difficult to accurately calculate the speed indication error of the speed measurement device; (2) When calibrating the acceleration indication error, according to the requirements of the regulation, any three accelerations within the range of (-1~2) m / s 2 shall be selected as the calibration points, but there must be one calibration point less than 0 m / s 2 . However, during actual testing, it is difficult for the driver to ensure that the acceleration of the vehicle is between (-1~2) m / s 2 when passing through the monitoring area by controlling the throttle, and it is even more impossible to ensure the repeatability measurement of each acceleration calibration point, resulting in difficulty in measuring the acceleration indication error during actual measurement; (3) When calibrating the acceleration indication error, it is also very difficult for the driver to make the vehicle perform a uniform acceleration motion when passing through the monitoring area by controlling the throttle, that is, it is difficult to determine the corresponding relationship of the acceleration during calibration; In summary, it is difficult for manual driving to control the test vehicle to be in a stable uniform motion state and uniform acceleration motion state, and the efficiency of calibrating the speed measurement device is low.

[0005] Therefore, in order to improve the efficiency of calibrating the speed measurement device, manual driving of the test vehicle is cancelled, and there is an urgent need in this technical field for an indoor calibration method for the speed measurement device of a motor vehicle exhaust remote detector. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an indoor calibration method for the speed measurement device of a motor vehicle exhaust remote detector.

[0007] The present invention is implemented as follows: An indoor calibration method for the speed measurement device of a motor vehicle exhaust remote detector includes the following steps: S1. Preparation stage: Install a calibration device, where the calibration device includes a frame, a driving mechanism, a control mechanism, and an obstacle. The driving mechanism is used to drive the obstacle to move linearly along the frame, and the control mechanism is used to set the parameters for the linear motion of the obstacle. The parameters include standard speed, standard acceleration, standard uniform motion time, and standard acceleration time; S2. Initialization stage: Stop the obstacle at the initial position; S3. Install the speed measurement device: When speed calibration is required, first select the standard speed, find the uniform motion area where the obstacle moves uniformly along the frame, and then place the speed measurement device on both sides of the uniform motion area, and then go to S4; When acceleration calibration is required, first select the standard acceleration, find the uniform acceleration region where the shielding object makes a uniform acceleration motion on the rack, then place the speed measuring device on both sides of the uniform acceleration region, and go to S5; S4. Speed calibration: Start the calibration device. The shielding object passes through the light transceiver space of the speed measuring device at the standard speed. The speed measuring device obtains the detected speed, compares the detected speed with the standard speed, calculates the speed indication error of the speed measuring device, and goes to S6; S5. Acceleration calibration: Start the calibration device. The shielding object passes through the light transceiver space of the speed measuring device at the standard acceleration. The speed measuring device obtains the detected acceleration, compares the detected acceleration with the standard acceleration, calculates the acceleration indication error of the speed measuring device, and goes to S6; S6. Complete the calibration of the speed measuring device.

[0008] Further, S3 further includes: A displacement encoder is provided between the shielding object and the rack, and the displacement encoder is used to feedback the displacement condition of the shielding object to the control mechanism; When the control mechanism sends the parameters of the standard speed and the standard uniform speed time to the driving mechanism, the control mechanism first records the uniform starting displacement between the shielding object and the initial position at the starting point of the standard uniform speed time. Then the control mechanism records the uniform ending displacement between the shielding object and the initial position at the ending point of the standard uniform speed time. The uniform ending displacement is subtracted from the uniform starting displacement to obtain the uniform acceleration region where the shielding object makes a uniform motion on the rack; When the control mechanism sends the parameters of the standard acceleration and the standard acceleration time to the driving mechanism, the control mechanism first records the acceleration starting displacement between the shielding object and the initial position at the starting point of the standard acceleration time. Then the control mechanism records the acceleration ending displacement between the shielding object and the initial position at the ending point of the standard uniform speed time. The acceleration ending displacement is subtracted from the acceleration starting displacement to obtain the uniform acceleration region where the shielding object makes a uniform acceleration motion on the rack.

[0009] Further, S4 further includes: The speed measuring device displays the detected speed and feedbacks the detected speed to the control mechanism, and the control mechanism calculates the speed indication error of the speed measuring device; S5 further includes: The speed measuring device displays the detected acceleration and feedbacks the detected acceleration to the control mechanism, and the control mechanism calculates the acceleration indication error of the speed measuring device; S6 further includes: The control mechanism determines the measurement performance result of the speed measuring device.

[0010] Further, in the step S1, the frame includes a cross beam and a guide rail, and the guide rail is fixedly arranged on the cross beam; The driving mechanism includes a servo motor, a driving wheel, a transmission belt, a driven wheel, a slider, a first mounting seat and a second mounting seat. The first mounting seat and the second mounting seat are respectively fixedly arranged at the front end and the rear end of the cross beam. The body of the servo motor is fixedly arranged on the first mounting seat. The output shaft of the servo motor is in transmission connection with the central hole of the driving wheel. The driven wheel is rotatably arranged on the second mounting seat. The transmission belt is wound around the driving wheel and the driven wheel. The slider is slidably connected with the guide rail, and the slider is also fixedly connected with the transmission belt; The control mechanism includes a servo control driver and a first computer. The servo control driver is electrically connected with the servo motor, and the first computer is electrically connected with the servo control driver; The shielding object is fixedly arranged on the slider; The speed measuring device includes a photoelectric sensor and a second computer. The light emitting end and the light receiving end of the photoelectric sensor are arranged oppositely and are respectively located on the left side and the right side of the guide rail. The photoelectric sensor is electrically connected with the second computer, and the second computer is also electrically connected with the first computer.

[0011] Further, a plurality of the photoelectric sensors are arranged at uniform intervals along the length direction of the cross beam.

[0012] Further, the calibration device further includes an operation panel, and the operation panel is electrically connected with the first computer. The operation panel has a reset button and a start button.

[0013] Compared with the background art, the beneficial effects or advantages of the technical solution of the present invention are as follows: 1. There is no need to manually drive a test vehicle. The shielding object is used to simulate the driving situation of the test vehicle. The shielding object passes through the monitoring area of the speed measuring device at a set standard speed and standard acceleration. The speed measuring device obtains the detected speed and detected acceleration, so as to realize the calibration of the speed measuring device. The movement state of the shielding object is accurately and stably controlled by the device, and the efficiency of calibrating the speed measuring device is improved. 2. The speed measuring device of the motor vehicle exhaust remote detector can be calibrated indoors as a device to be calibrated. The shielding object of the calibration device can pass through the monitoring area of the speed measuring device at a uniform speed or a uniform acceleration state, solving the problem that the speed and acceleration measured by the standard speedometer are not corresponding to the speed and acceleration measured by the speed measuring device when manually driving a test vehicle during the outdoor calibration process. The calibration result of the present invention has the advantages of accuracy, rapidity and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below with reference to the accompanying drawings in conjunction with embodiments.

[0015] Figure 1 It is a schematic structural diagram of the indoor calibration system of the vehicle exhaust remote detector speed measurement device in the present invention.

[0016] Figure 2 It is a schematic diagram of the occluder located between the light emitting end and the light receiving end of the speed measurement device in the present invention.

[0017] Figure 3 It is a schematic diagram of the positions of the top plate, bottom plate, left plate, right plate and slider in the present invention.

[0018] Figure 4 It is a schematic diagram of the positions of the first limit switch, the second limit switch and the occluder in the present invention.

[0019] Figure 5 It is a schematic connection diagram between the servo motor, the driving wheel and the transmission belt in the present invention.

[0020] Figure 6 It is a schematic diagram of the position of the horizontal strip hole in the second mounting seat in the present invention.

[0021] Figure 7 It is a schematic connection diagram between the driven wheel, the tensioning shaft and the transmission belt in the present invention.

[0022] Figure 8 It is a working principle block diagram among the control mechanism, the driving mechanism and the occluder in the present invention.

[0023] Figure 9 It is a schematic curve diagram of the relationship between the speed and time of the occluder in the present invention.

[0024] Figure 10 It is a flow chart of the calibration method in the present invention.

[0025] Reference numerals: calibration device 1; frame 11; cross beam 111; hollow structure 1111; guide rail 112; ladder-shaped column 113; connecting plate 114; cup foot 115; adjusting bolt 116; driving mechanism 12; servo motor 121; driving wheel 122; transmission belt 123; driven wheel 124; slider 125; first mounting seat 126; second mounting seat 127; horizontal strip hole 1271; tensioning shaft 128; pressing plate 129; control mechanism 13; servo control driver 131; first computer 132; first limit switch 133; second limit switch 134; displacement encoder 135; occluder 14; top plate 141; bottom plate 142; left plate 143; right plate 144; buffer mechanism 15; speed measurement device 2; photoelectric sensor 21; light emitting end 211; light receiving end 212. Detailed implementation manners

[0026] An indoor calibration method for a speed measurement device of a motor vehicle exhaust remote control detector is provided in an embodiment of the present invention. The general idea of the technical solution is as follows: By simulating the driving conditions of a test vehicle, the disadvantages of manually driving a test vehicle are overcome, and a calibration device is manufactured. The calibration device includes a frame, a driving mechanism, a control mechanism, and an obstruction. The obstruction moves linearly along the frame through the driving mechanism. The control mechanism is used to control the state of the linear movement of the obstruction. The obstruction passes through the monitoring area of the speed measurement device. The calibration personnel can conveniently set parameters such as the standard speed, standard acceleration, etc. of the obstruction in the control mechanism. The detection speed and detection acceleration are obtained by the speed measurement device. By comparing the standard speed and the detection speed, the speed indication error of the speed measurement device is calculated. By comparing the standard acceleration and the detection acceleration, the acceleration indication error of the speed measurement device is calculated. Since there is no need to manually drive a test vehicle, the speed measurement device of the motor vehicle exhaust remote control detector can be calibrated indoors; the speed measurement device belongs to the motor vehicle exhaust remote control detector.

[0027] To better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments.

[0028] Refer to Figures 1 to 10 , the preferred embodiment of the present invention.

[0029] An indoor calibration method for a speed measurement device of a motor vehicle exhaust remote sensing detector includes the following steps: S1. Preparation stage: Install the calibration device 1. The calibration device 1 includes a frame 11, a driving mechanism 12, a control mechanism 13, and an obstruction 14. The driving mechanism 12 is used to drive the obstruction 14 to move linearly along the frame 11. The control mechanism 13 is used to set the parameters of the linear movement of the obstruction 14. The parameters include standard speed, standard acceleration, standard uniform speed time, and standard acceleration time; S2. Initialization stage: Stop the obstruction 14 at the initial position; S3. Install the speed measurement device 2: When speed calibration is required, first select the standard speed, find the uniform speed area where the obstruction 14 moves at a uniform speed on the frame 11, and then place the speed measurement device 2 on both sides of the uniform speed area, and go to S4; When acceleration calibration is required, first select the standard acceleration, find the uniform acceleration area where the obstruction 14 moves with uniform acceleration on the frame 11, and then place the speed measurement device 2 on both sides of the uniform acceleration area, and go to S5; S4, Speed Calibration: Start the calibration device 1. The occluder 14 passes through the light transceiver space of the speed measuring device 2 at a standard speed. The speed measuring device 2 obtains the detected speed, compares the detected speed with the standard speed, calculates the speed indication error of the speed measuring device 2, and proceeds to S6; S5, Acceleration Calibration: Start the calibration device 1. The occluder 14 passes through the light transceiver space of the speed measuring device 2 at a standard acceleration. The speed measuring device 2 obtains the detected acceleration, compares the detected acceleration with the standard acceleration, calculates the acceleration indication error of the speed measuring device 2, and proceeds to S6; S6, Complete the calibration of the speed measuring device 2.

[0030] The beneficial effects or advantages of the technical solution of the present invention: There is no need to manually drive a test vehicle. The occluder is used to simulate the driving situation of the test vehicle. The occluder passes through the monitoring area of the speed measuring device at a set standard speed and standard acceleration. The speed measuring device obtains the detected speed and detected acceleration, realizing the calibration of the speed measuring device. The movement state of the occluder is precisely and stably controlled by the device, improving the efficiency of calibrating the speed measuring device.

[0031] As a device to be calibrated, the speed measuring device of the motor vehicle exhaust remote detector can be calibrated indoors. The occluder of the calibration device can pass through the monitoring area of the speed measuring device at a uniform speed or a uniform acceleration, solving the problem that the speed and acceleration measured by the standard speedometer do not correspond to the speed and acceleration measured by the speed measuring device during the outdoor calibration process when manually driving a test vehicle. The calibration result of the present invention has the advantages of accuracy, speed, and stability.

[0032] According to actual needs, the calibration staff can set multiple standard speeds and corresponding standard uniform times, set multiple standard accelerations and corresponding standard acceleration times. The first computer 132 of the control mechanism 13 can conveniently set parameters, and then the driving mechanism 12 drives the occluder 14 according to the parameters. The first computer 132 of the control mechanism 13 is connected to the second computer (not shown) of the speed measuring device 2 through a signal line. Therefore, during the calibration process, the time of the first computer 132 and the second computer is unified, which helps to make the detected speed of the speed measuring device 2 correspond one by one with the set standard speed.

[0033] Further, S3 further includes: A displacement encoder 135 is provided between the occluder 14 and the frame 11. The displacement encoder 135 is used to feedback the displacement situation of the occluder 14 to the control mechanism 13; When the control mechanism 13 sends the parameters of the standard speed and the standard constant-speed time to the driving mechanism 12, the control mechanism 13 first records the constant-speed starting displacement between the shielding object 14 and the initial position at the starting point of the standard constant-speed time. Then, the control mechanism 13 records the constant-speed ending displacement between the shielding object 14 and the initial position at the ending point of the standard constant-speed time. The constant-speed ending displacement is subtracted from the constant-speed starting displacement to obtain the constant-speed area where the shielding object 14 moves at a constant speed on the frame 11. When the control mechanism 13 sends the parameters of the standard acceleration and the standard acceleration time to the driving mechanism 12, the control mechanism 13 first records the acceleration starting displacement between the shielding object 14 and the initial position at the starting point of the standard acceleration time. Then, the control mechanism 13 records the acceleration ending displacement between the shielding object 14 and the initial position at the ending point of the standard constant-speed time. The acceleration ending displacement is subtracted from the acceleration starting displacement to obtain the uniformly accelerated area where the shielding object 14 moves with uniform acceleration on the frame 11.

[0034] In this embodiment, one end of the cross beam 111 of the shielding object 14 is the initial position, and the other end of the cross beam 111 is the end position. During speed calibration, the shielding object 14 accelerates from zero speed at the initial position to the standard speed with a conventional acceleration and a conventional acceleration time, then moves at a constant speed with the standard speed and the standard constant-speed time, and finally decelerates from the standard speed to zero speed with a conventional acceleration and a conventional acceleration time and stops at the cross beam 111.

[0035] During acceleration calibration, the shielding object 14 accelerates from zero speed at the initial position to the conventional speed with the standard acceleration and the standard acceleration time, then moves at a constant speed with the conventional speed and the conventional constant-speed time, and finally decelerates from the conventional speed to zero speed with the standard acceleration and the standard acceleration time and stops at the cross beam 111.

[0036] The constant-speed area and the uniformly accelerated area of the shielding object 14 on the cross beam 111 can be determined by pre-measurement by the calibration staff.

[0037] Further, step S4 further includes: the speed measuring device 2 displays the detected speed and feeds back the detected speed to the control mechanism 13, and the control mechanism 13 calculates the speed indication error of the speed measuring device 2. Step S5 further includes: the speed measuring device 2 displays the detected acceleration and feeds back the detected acceleration to the control mechanism 13, and the control mechanism 13 calculates the acceleration indication error of the speed measuring device 2. Step S6 further includes: the control mechanism 13 determines the measurement performance result of the speed measuring device 2.

[0038] In this embodiment, the control mechanism 13 automatically calculates the speed indication error and acceleration indication error of the speed measuring device 2, improving the calculation efficiency. When the speed indication error and acceleration indication error are within the specified range, the control mechanism 13 determines that the measurement performance result of the speed measuring device 2 is qualified; when the speed indication error and acceleration indication error are outside the specified range, the control mechanism 13 determines that the measurement performance result of the speed measuring device 2 is unqualified.

[0039] Further, in S1, the frame 11 includes a cross beam 111 and a guide rail 112, and the guide rail 112 is fixedly arranged on the cross beam 111; The driving mechanism 12 includes a servo motor 121, a driving wheel 122, a transmission belt 123, a driven wheel 124, a slider 125, a first mounting seat 126 and a second mounting seat 127. The first mounting seat 126 and the second mounting seat 127 are respectively fixedly arranged at the front end and the rear end of the cross beam 111. The body of the servo motor 121 is fixedly arranged on the first mounting seat 126. The output shaft of the servo motor 121 is in transmission connection with the central hole of the driving wheel 122. The driven wheel 124 is rotatably arranged on the second mounting seat 127. The transmission belt 123 is wound around the driving wheel 122 and the driven wheel 124. The slider 125 is slidably connected with the guide rail 112, and the slider 125 is also fixedly connected with the transmission belt 123; The control mechanism 13 includes a servo control driver 131 and a first computer 132. The servo control driver 131 is electrically connected with the servo motor 121, and the first computer 132 is electrically connected with the servo control driver 131; The shielding object 14 is fixedly arranged on the slider 125; The speed measuring device 2 includes a photoelectric sensor 21 and a second computer (not shown). The light emitting end 211 and the light receiving end 212 of the photoelectric sensor 21 are arranged oppositely and are respectively located on the left side and the right side of the guide rail 112. The photoelectric sensor 21 is electrically connected with the second computer, and the second computer is also electrically connected with the first computer 132.

[0040] The servo motor 121 operates precisely according to the instructions of the servo control driver 131. With the help of the driving wheel 122, the transmission belt 123, and the driven wheel 124, the slider 125 drives the shielding object 14 to perform precise linear motion. The rotational speed of the servo motor 121 corresponds to the speed of the shielding object 14. The speed and acceleration parameters to be calibrated are pre-saved in the servo control driver 131, and the servo control driver 131 performs automatic conversion processing. The sizes of the driving wheel 122, the transmission belt 123, the driven wheel 124, and the slider 125 are pre-set. Usually, when the value of the speed is positive, the shielding object 14 is in the forward state; when the value of the speed is negative, the shielding object 14 is in the backward state; when the value of the acceleration is positive, the shielding object 14 is in the speed-up state; when the value of the acceleration is negative, the shielding object 14 is in the speed-down state.

[0041] The staff inputs the parameters used for calibration into the first computer 132. The first computer 132 sends a control signal to the servo control driver 131 according to the parameters, thereby controlling the operating state of the servo motor 121. The second computer pre-saves the distance value between two adjacent photoelectric sensors 21, records the time points when the light is blocked, and then calculates the detected speed. The second computer then feeds back the time points and the corresponding detected speeds and detected accelerations to the first computer 132. The first computer 132 calculates the speed indication error of the speed measuring device 2 by comparing the standard speed and the detected speed, and calculates the acceleration indication error of the speed measuring device 2 by comparing the standard acceleration and the detected acceleration. Finally, the calibration result of the speed measuring device 2 is determined.

[0042] When the shielding object 14 passes between the light emitting end 211 and the light receiving end 212 of the photoelectric sensor 21 of the speed measuring device 2, based on the principle of fast speed measurement by the light shielding method, the photoelectric sensor sends a light shielding signal to the second computer, and the second computer records the time point at this time. The shielding object passes through the first photoelectric sensor and the second photoelectric sensor in turn, and the second computer records the first time point and the second time point respectively. Since the distance between the first photoelectric sensor and the second photoelectric sensor is pre-determined, the difference between the first time point and the second time point is the time period during which the shielding object moves. According to the distance and the time period, the speed can be calculated. When the shielding object passes through more than three photoelectric sensors with the same spacing, the speed corresponding to the time period can be calculated, and then the change in speed, that is, the acceleration, can be obtained.

[0043] Furthermore, the plurality of photoelectric sensors are arranged at equal intervals along the length direction of the cross beam.

[0044] The beneficial effects of this technical solution: The distances between the plurality of photoelectric sensors 21 are pre-set and are known parameters, which are saved in the control mechanism 13. The shielding object 14 passes through the light receiving and transmitting spaces of the plurality of photoelectric sensors 21 in turn, improving the accuracy of speed measurement.

[0045] Further, the calibration device further includes an operation panel (not shown), the operation panel is electrically connected to the first computer, and the operation panel has a reset button and a start button.

[0046] Advantages of this technical solution: Facilitate manual operation by staff and set parameters. The reset button is used to make the shield 14 in the initial position, and the start button is used to start the calibration work.

[0047] Further, the frame 11 further includes trapezoidal columns 113 and connecting plates 114. The upper ends of the trapezoidal columns 113 are fixedly connected to the lower surface of the cross beam 111. A plurality of the trapezoidal columns 113 are arranged at intervals along the length direction of the cross beam 111, and the connecting plates 114 are arranged between adjacent two of the trapezoidal columns 113.

[0048] Advantages of this technical solution: The trapezoidal columns 113 improve the stability of supporting the cross beam 111, and the connecting plates 114 play a role in reinforcement, ensuring that the overall frame 11 has good rigidity.

[0049] Further, the frame 11 further includes a height adjustment component. The height adjustment component includes cup feet 115 and adjustment bolts 116. The lower end of the adjustment bolt 116 is fixedly connected to the cup feet 115. The lower end of the trapezoidal column 113 has an adjustment screw hole, and the upper end of the adjustment bolt 116 is connected to the adjustment screw hole.

[0050] Advantages of this technical solution: By using the adjustment bolt 116, the height of the cup feet 115 can be adjusted, thereby realizing the adjustment of the levelness of the overall frame 11. The cup feet 115 have anti-slip and shock-absorbing functions, which can effectively eliminate the impact and vibration generated when the shield 14 runs at high speed.

[0051] Further, the driving mechanism 12 further includes a tensioning shaft 128, rolling bearings (not shown), and a pressing plate 129. The central hole of the driven wheel 124 is fixedly connected to the outer ring of the rolling bearing. The inner ring of the rolling bearing is fixedly connected to the middle part of the tensioning shaft 128. Horizontal strip holes 1271 are provided on both the front and rear sides of the second mounting seat 127. The two ends of the tensioning shaft 128 are respectively slidably connected to the two horizontal strip holes 1271, and the two ends of the tensioning shaft 128 are respectively fixedly connected to the second mounting seat 127 through the two pressing plates 129.

[0052] Advantages of this technical solution: By changing the position of the tensioning shaft 128 in the horizontal strip hole 1271, thereby changing the position of the driven wheel 124, the tension of the transmission belt 123 can be adjusted, and then the tensioning shaft 128 is fixed to the second mounting seat 127 with the pressing plate 129.

[0053] Specifically, the output shaft of the servo motor 121 is connected to the central hole of the driving wheel 122 through a flat key. The driving wheel 122 and the transmission belt 123 are connected by an arc-shaped tooth fit. At this time, the driven wheel 124 serves as a tensioning wheel. There is an interference fit between the central hole of the driven wheel 124 and the outer ring of the rolling bearing. The inner ring of the rolling bearing is connected to the tensioning shaft 128 through a flat key, and the tensioning shaft 128 is fixedly installed on the second mounting seat 127.

[0054] Furthermore, the calibration device 1 further includes a buffer mechanism 15. The two buffer mechanisms 15 are respectively fixedly arranged on the first mounting seat 126 and the second mounting seat 127, and the slider 125 is located between the two buffer mechanisms 15.

[0055] Beneficial effects of this technical solution: The buffer mechanism 15 plays a final layer of protection for the slider 125 moving at high speed; the buffer mechanism 15 is composed of a hydraulic damper. If the slider 125 gets out of control during movement, the slider 125 hits the hydraulic damper, and the damping effect is used to reduce the speed of the slider 125 until the slider 125 stops moving.

[0056] Furthermore, the cross beam 111 is provided with a hollow structure 1111 along its own length direction, and the transmission belt 123 passes through the hollow structure 1111.

[0057] Beneficial effects of this technical solution: The cross beam 111 is made of aluminum alloy material with a rectangular hollow cross-section. This structure can ensure that the cross beam 111 has good rigidity under a large-length structure, prevent the deformation of the cross beam 111. In addition, the hollow structure 1111 can also be used for the transmission belt 123 to pass through, which helps to make rational use of space.

[0058] Furthermore, the shielding object 14 is surrounded by a top plate 141, a bottom plate 142, a left plate 143 and a right plate 144, and the bottom plate 142 is fixedly connected to the slider.

[0059] Beneficial effects of this technical solution are: The cooperation between the top plate 141, the bottom plate 142, the left plate 143 and the right plate 144 improves the strength of the shielding object 14. The left and right sides of the shielding object 14 are through-hole structures, which reduces the air resistance of the shielding object 14 during movement.

[0060] Furthermore, the control mechanism 13 further includes a first limit switch 133 and a second limit switch 134. The first limit switch 133 and the second limit switch 134 are respectively fixedly arranged at the front end and the rear end of the cross beam 111, and both the first limit switch 133 and the second limit switch 134 are electrically connected to the servo control driver 131.

[0061] Beneficial effects of this technical solution: When the first limit switch 133 senses the slider 125 or the second limit switch 134 senses the slider 125, the first limit switch 133 or the second limit switch 134 sends a signal to the servo control driver 131, and the servo control driver 131 causes the servo motor 121 to stop urgently to prevent accidents.

[0062] The working principle of the present invention will be described in detail below: (1) Install the calibration device 1 and the speed measurement device 2 of the motor vehicle exhaust remote sensor indoors.

[0063] The first computer 132 of the control mechanism 13 is connected to the servo control driver 131 through a bus. The servo control driver 131 sends a driving instruction to the servo motor 121, and the servo motor 121 starts to rotate. The servo motor 121 causes the driving wheel 122 to rotate. The driving wheel 122 and the transmission belt 123 are matched by arc-shaped teeth. Furthermore, the driving wheel 122 causes the transmission belt 123 to move, and the transmission belt 123 causes the slider 125 to move on the linear guide 112, so that the shielding object 14 installed on the slider 125 generates a standard speed and a standard acceleration.

[0064] (2) During calibration, turn on the power supply and confirm whether the shielding object 14 is in the initial position. If it is not in the initial position, press the reset button to stop the shielding object 14 at the initial position.

[0065] When performing speed calibration, select the parameter of the corresponding standard speed, preset the acceleration distance of the shielding object 14, ensure that the speed measurement device 2 to be calibrated is within the uniform speed area, and place the light emitting end 211 and the light receiving end 212 of the photoelectric sensor 21 of the speed measurement device 2 on both sides of the cross beam 111 of the calibration device 1 respectively. After installing the speed measurement device 2, start the calibration device 1. After the shielding object 14 passes through the monitoring area of the speed measurement device 2 at a uniform speed of the set standard speed v1, the speed measurement device 2 measures a detection speed v2 due to the shielding of the light beam by the shielding object 14 and based on the principle of rapid speed measurement by the light shielding method. The difference between the detection speed v2 and the standard speed v1 is the speed indication error of the speed measurement device 2. Repeat the above steps three times to measure the repeatability error of speed measurement.

[0066] When performing acceleration calibration, select the parameters of the corresponding standard acceleration to ensure that the speed measuring device 2 to be calibrated is within the uniformly accelerating area, and place the light emitting end 211 and the light receiving end 212 of the photoelectric sensor 21 of the speed measuring device 2 on both sides of the cross beam 111 of the calibration device 1 respectively. After installing the speed measuring device 2, start the calibration device 1. After the shielding object 14 passes through the monitoring area of the speed measuring device 2 at a uniformly accelerating speed with the set standard acceleration a1, since the shielding object 14 blocks the light beam, the speed measuring device 2 measures a detected acceleration a2 based on the principle of rapid speed measurement by the light shielding method. The difference between the detected acceleration a2 and the standard acceleration a1 is the acceleration indication error of the speed measuring device 2. Repeat the above steps three times to measure the repeatability error of the acceleration measurement.

[0067] Although the specific embodiments of the present invention have been described above, those skilled in the art of this technology should understand that the specific embodiments we described are illustrative rather than used to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered by the scope protected by the claims of the present invention.

Claims

1. An indoor calibration method for a speed measurement device of a motor vehicle exhaust remote sensing detector, characterized in that, It includes the following steps: S1. Preparation stage: Install a calibration device, which includes a frame, a driving mechanism, a control mechanism and an occluder. The driving mechanism is used to drive the occluder to move linearly along the frame, and the control mechanism is used to set the parameters of the linear movement of the occluder. The parameters include standard speed, standard acceleration, standard constant-speed time and standard acceleration time; S2. Initialization stage: Stop the occluder at the initial position; S3. Install a speed measurement device: When speed calibration is required, first select the standard speed, find the constant-speed area where the occluder moves at a constant speed along the frame, then place the speed measurement device on both sides of the constant-speed area, and go to S4; When acceleration calibration is required, first select the standard acceleration, find the uniformly accelerated area where the occluder moves with uniform acceleration along the frame, then place the speed measurement device on both sides of the uniformly accelerated area, and go to S5; S4. Speed calibration: Start the calibration device, the occluder passes through the light transceiver space of the speed measurement device at the standard speed, the speed measurement device obtains the detected speed, compare the detected speed with the standard speed, calculate the speed indication error of the speed measurement device, and go to S6; S5. Acceleration calibration: Start the calibration device, the occluder passes through the light transceiver space of the speed measurement device at the standard acceleration, the speed measurement device obtains the detected acceleration, compare the detected acceleration with the standard acceleration, calculate the acceleration indication error of the speed measurement device, and go to S6; S6. Complete the calibration of the speed measurement device.

2. The indoor calibration method of a speed measurement device for a motor vehicle exhaust remote sensing detector according to claim 1, characterized in that, S3 further includes: A displacement encoder is provided between the occluder and the frame, and the displacement encoder is used to feedback the displacement condition of the occluder to the control mechanism; When the control mechanism sends the parameters of the standard speed and the standard constant-speed time to the driving mechanism, the control mechanism first records the constant-speed starting displacement between the occluder and the initial position at the starting point of the standard constant-speed time, and then the control mechanism records the constant-speed ending displacement between the occluder and the initial position at the ending point of the standard constant-speed time. Subtract the constant-speed ending displacement from the constant-speed starting displacement to obtain the constant-speed area where the occluder moves at a constant speed along the frame; When the control mechanism sends the parameters of the standard acceleration and the standard acceleration time to the driving mechanism, the control mechanism first records the acceleration starting displacement between the occluder and the initial position at the starting point of the standard acceleration time, and then the control mechanism records the acceleration ending displacement between the occluder and the initial position at the ending point of the standard acceleration time. Subtract the acceleration ending displacement from the acceleration starting displacement to obtain the uniformly accelerated area where the occluder moves with uniform acceleration along the frame.

3. The indoor calibration method of a speed measurement device for a motor vehicle exhaust remote sensing detector according to claim 1, characterized in that, S4 further includes: The speed measurement device displays the detected speed and feedbacks the detected speed to the control mechanism, and the control mechanism calculates the speed indication error of the speed measurement device; The S5 further includes: the speed measuring device displays the detected acceleration and feeds back the detected acceleration to the control mechanism, and the control mechanism calculates the acceleration indication error of the speed measuring device; The S6 further includes: the control mechanism determines the measurement performance result of the speed measuring device.

4. The indoor calibration method of a speed measurement device for a motor vehicle exhaust remote sensing detector according to claim 1, characterized in that, In the S1, the frame includes a cross beam and a guide rail, and the guide rail is fixedly arranged on the cross beam; The driving mechanism includes a servo motor, a driving wheel, a transmission belt, a driven wheel, a slider, a first mounting seat and a second mounting seat. The first mounting seat and the second mounting seat are respectively fixedly arranged at the front end and the rear end of the cross beam. The body of the servo motor is fixedly arranged on the first mounting seat. The output shaft of the servo motor is in transmission connection with the central hole of the driving wheel. The driven wheel is rotatably arranged on the second mounting seat. The transmission belt is wound around the driving wheel and the driven wheel. The slider is slidably connected with the guide rail, and the slider is also fixedly connected with the transmission belt; The control mechanism includes a servo control driver and a first computer. The servo control driver is electrically connected with the servo motor, and the first computer is electrically connected with the servo control driver; The shielding object is fixedly arranged on the slider; The speed measuring device includes a photoelectric sensor and a second computer. The light emitting end and the light receiving end of the photoelectric sensor are arranged opposite to each other and are respectively located on the left side and the right side of the guide rail. The photoelectric sensor is electrically connected with the second computer, and the second computer is also electrically connected with the first computer.

5. The indoor calibration method of a vehicle exhaust remote sensing detector speed measurement device according to claim 4, characterized in that, A plurality of the photoelectric sensors are evenly arranged at intervals along the length direction of the cross beam.

6. The indoor calibration method of a speed measurement device for a motor vehicle exhaust remote sensing detector according to claim 4, characterized in that, The calibration device further includes an operation panel, and the operation panel is electrically connected with the first computer. The operation panel has a reset button and a start button.

Images