A road friction coefficient detection device for highway pavement detection

Abstract

The present invention belongs to the technical field of road surface detection, and in particular relates to a road friction coefficient detection device for highway road surface detection, including a vehicle body and a controller arranged inside the vehicle body. A detachable mounting bracket is installed at the tail of the vehicle body. One end of the mounting bracket away from the vehicle body is installed with a mounting plate, and a detection cover is installed on the side wall of the mounting plate. It further includes: a friction detection unit installed inside the detection cover for detecting the friction of the road surface; a plurality of detection wheels are all arranged below the mounting plate. The present invention can automatically detect the friction coefficient based on the difference in road surface roughness, reduce unnecessary detection work, improve the overall detection efficiency, and to a certain extent reduce the errors caused by factors such as tire wear and continuous driving at high temperature on the determination of the friction coefficient, and can reduce the impact of road sand and gravel on the detection accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of road surface detection, and particularly relates to a road friction coefficient detection device for highway road surface detection. Background Art

[0002] The road friction coefficient is related to highway traffic safety. When a vehicle is traveling, a good friction coefficient can ensure sufficient friction between the tire and the road surface, guarantee the effectiveness of braking and the stability of steering. In order to ensure road safety, it is necessary to regularly carry out road friction detection, which is of great significance for preventing accidents in advance and ensuring the safe and unobstructed passage of the road.

[0003] Currently, there are many methods for detecting the road friction coefficient. For example, the highway road surface friction detection platform with the patent publication number of CN109187332A adopts the swing-type friction coefficient measurement method, which can accurately detect the road surface friction, but it needs to be operated in a static state and cannot detect continuous road surfaces, resulting in low efficiency. To achieve continuous detection, pressure and torque sensors are installed on the detection vehicle at present. By detecting the wheel torque under the action of load, the friction coefficient can be dynamically measured. In order to avoid the interference of factors such as vehicle driving vibration, the detection vehicle needs to maintain a constant slow speed (such as below 15 mph), which still leads to low efficiency of road surface friction detection. In addition, the continuous driving of vehicle tires is easy to wear, and the friction between the worn tires and the road surface becomes larger, seriously affecting the accuracy of the friction coefficient measurement. Summary of the Invention

[0004] The purpose of the present invention is to solve the above problems and provide a road friction coefficient detection device for highway road surface detection.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A road friction coefficient detection device for highway road surface detection includes a vehicle body and a controller arranged inside the vehicle body. A detachable mounting bracket is installed at the tail of the vehicle body. One end of the mounting bracket away from the vehicle body is installed with a mounting plate, and a detection cover is installed on the side wall of the mounting plate. It further includes:

[0006] A friction detection unit, installed inside the detection cover, for detecting the friction of the road surface;

[0007] A plurality of detection wheels are all arranged below the mounting plate. A plurality of metal teeth are evenly distributed in a ring on the wheel wall of the detection wheel. A plurality of vertical cavities are opened inside the mounting plate, and a position detection component is arranged inside each vertical cavity. The position detection component is used to measure the height of the detection wheel and convert the height into an electrical signal and feedback it to the controller;

[0008] The water tank is installed inside the vehicle body. A metering and comparison unit is installed on the water tank. The controller controls the operation of the metering and comparison unit according to the electrical signal fed back by the position detection component, and the controller controls the operation of the friction resistance detection unit according to the difference in the electrical signals fed back by the metering and comparison unit.

[0009] Preferably, the friction resistance detection unit includes an electric hydraulic cylinder fixedly inserted at the top of the detection cover. A detection plate is installed at the telescopic end of the electric hydraulic cylinder. A fixed frame is arranged below the detection plate. A tire is rotatably connected to the bottom of the fixed frame. An elastic telescopic component and a pressure transmitter are arranged between the fixed frame and the detection plate. A torsion sensor is installed at the bottom of the fixed frame, and the detection end of the torsion sensor is in transmission connection with the wheel axle of the tire. The electric hydraulic cylinder, the pressure transmitter and the torsion sensor are all electrically connected to the controller.

[0010] Preferably, each of the position detection components includes a wheel frame. The detection wheel is rotatably arranged inside the wheel frame. The wheel frame is detachably connected to the bottom of the mounting plate. A sliding rod is installed at the top of the wheel frame, and the sliding rod is slidably connected to the lower cavity wall of the vertical cavity. A ranging probe is inserted at the top of the vertical cavity. The ranging probe is used to detect the height of the top of the sliding rod and convert the height into an electrical signal to be fed back to the controller.

[0011] Preferably, the metering and comparison unit includes a high-pressure water pump fixedly installed outside the water tank. The suction end of the high-pressure water pump is communicated with the inside of the water tank. A water outlet pipe is installed at the water outlet end of the high-pressure water pump. An upper hollow plate is installed on the side wall of the mounting plate, and the upper hollow plate is communicated with the water outlet pipe. A plurality of left shunt pipes and a plurality of right shunt pipes are fixedly inserted at the bottom of the upper hollow plate. A normally open proportional solenoid valve is installed inside each of the left shunt pipes. A normally closed proportional solenoid valve is installed inside each of the right shunt pipes. A liquid flowmeter is installed at the pipe end of each of the right shunt pipes. The controller controls the opening and closing degrees of the corresponding normally open proportional solenoid valve and normally closed proportional solenoid valve according to the electrical signal fed back by the ranging probe. The liquid flowmeter is used to detect the liquid flow passing through the inside of the right shunt pipe, and the controller controls the operation of the friction resistance detection unit according to the electrical signal fed back by the liquid flowmeter. A cleaning component is installed at the front position of the vehicle body, and the cleaning component is communicated with the liquid outlet ends of each of the left shunt pipes and each of the liquid flowmeters.

[0012] Preferably, the cleaning component includes a lower hollow plate fixedly installed on the side wall of the mounting plate. The liquid outlet ends of each of the left shunt pipes and each of the liquid flowmeters are communicated with the lower hollow plate. An infusion pipe is installed on the side wall of the lower hollow plate. The infusion pipe passes under the chassis of the vehicle body and is fixedly communicated with a water spraying hollow plate. The water spraying hollow plate is detachably connected to the side wall of the front of the vehicle body. A plurality of inclined cleaning nozzles are fixedly inserted on the side wall of the water spraying hollow plate.

[0013] Preferably, a flushing shunt pipe is fixedly communicated with the pipe wall of the water outlet pipe, and the liquid outlet end of the flushing shunt pipe extends into the interior of the detection cover. A flushing nozzle is fixedly installed on the inner wall of the detection cover, and the liquid outlet end of the flushing nozzle faces the lower side of the side wall of the tire. A flushing electric control valve is installed inside the flushing shunt pipe, and a cleaning electric control valve is installed at a position below the flushing shunt pipe inside the water outlet pipe. Both the flushing electric control valve and the cleaning electric control valve are electrically connected to the controller.

[0014] Preferably, a shell-and-tube heater is installed at the water inlet end of the water outlet pipe, and the water inlet end of the shell-and-tube heater is communicated with the water outlet end of the high-pressure water pump. The shell-and-tube heater is electrically connected to the controller.

[0015] Preferably, two groups of symmetric bumpers are installed at the rear of the vehicle body, and the detection cover is arranged between the two groups of bumpers.

[0016] Compared with the existing technology, the advantages of a road friction coefficient detection device for highway pavement detection are as follows:

[0017] Through the mutual cooperation of the vehicle body, controller, mounting bracket, mounting plate, detection cover and friction detection unit, the friction of the road surface can be detected and the road friction coefficient can be measured. And through the mutual cooperation of the detection wheel, metal teeth, vertical cavity, position detection component and measurement and comparison unit, based on the roughness difference of the road surface, the personnel can be automatically reminded to carry out the road friction detection work at the positions with large roughness differences on the road surface, and it is not necessary to continuously detect through the friction detection unit. This can not only appropriately increase the vehicle speed and accelerate the detection process, but also reduce the errors caused by factors such as tire wear and continuous driving at high temperature to the measurement of the friction coefficient to a certain extent.

[0018] Through the provided water tank, it can be used as the water source of the measurement and comparison unit, and the measurement and comparison unit cooperates with the cleaning component to clean the sundries such as sand and gravel that may exist on the driving path, avoiding the influence of sundries such as sand and gravel on the measurement of the road surface friction coefficient. Secondly, after humidifying the road surface, the friction coefficient of the road surface can be detected on the slippery road surface, so as to be used to judge whether the friction coefficient of the road surface meets the driving safety requirements in rainy days.

[0019] Through the provided flushing shunt pipe, flushing electric control valve, cleaning electric control valve and flushing nozzle, after the tire detection is completed, the sand and gravel and the like that may adhere to the tire surface can be removed, avoiding affecting the accuracy of the detection of the subsequent road sections. And with the cooperation of the shell-and-tube heater provided, it can not only simulate the friction coefficient between the tire and the road surface under high temperature during driving, but also keep the tire at a stable temperature before detection, which can further improve the measurement accuracy of the friction coefficient. Description of the Drawings

[0020] Figure 1It is a schematic structural diagram of a road friction coefficient detection device for highway pavement detection provided by the present invention;

[0021] Figure 2 It is a schematic internal structure diagram of the vehicle body of a road friction coefficient detection device for highway pavement detection provided by the present invention;

[0022] Figure 3 It is a schematic internal structure diagram of the detection cover of a road friction coefficient detection device for highway pavement detection provided by the present invention;

[0023] Figure 4 It is a schematic internal structure diagram of the mounting plate of a road friction coefficient detection device for highway pavement detection provided by the present invention;

[0024] Figure 5 It is a road friction coefficient detection device for highway pavement detection provided by the present invention Figure 4 The enlarged structure diagram of part A in;

[0025] Figure 6 It is a schematic connection structure diagram of the upper hollow plate and the lower hollow plate of a road friction coefficient detection device for highway pavement detection provided by the present invention;

[0026] Figure 7 It is a schematic front structure diagram of the vehicle body of a road friction coefficient detection device for highway pavement detection provided by the present invention.

[0027] In the figure: 1 vehicle body, 2 controller, 3 mounting bracket, 4 mounting plate, 5 detection cover, 6 friction detection unit, 61 electric hydraulic cylinder, 62 detection plate, 63 fixing frame, 64 tire, 65 elastic telescopic component, 66 pressure transmitter, 67 torque sensor, 7 detection wheel, 8 metal tooth, 9 vertical cavity, 10 position detection component, 101 wheel frame, 102 sliding rod, 103 distance measuring probe, 11 water tank, 12 measurement and comparison unit, 121 high-pressure water pump, 122 water outlet pipe, 123 upper hollow plate, 124 left shunt pipe, 125 right shunt pipe, 126 normally open proportional solenoid valve, 127 normally closed proportional solenoid valve, 128 liquid flow meter, 13 cleaning component, 131 lower hollow plate, 132 infusion pipe, 133 water spraying hollow plate, 134 cleaning nozzle, 14 flushing shunt pipe, 15 flushing nozzle, 16 flushing electric control valve, 17 cleaning electric control valve, 18 tubular heater, 19 bumper. Detailed implementation manners

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0029] Such as Figures 1-7As shown in the figure, a road friction coefficient detection device for highway pavement detection includes a vehicle body 1 and a controller 2 disposed inside the vehicle body 1. A detachable mounting bracket 3 is installed at the tail of the vehicle body 1. One end of the mounting bracket 3 away from the vehicle body 1 is installed with a mounting plate 4, and a detection cover 5 is installed on the side wall of the mounting plate 4. Two groups of symmetric bumper bars 19 are installed at the rear of the vehicle body 1, and the detection cover 5 is disposed between the two groups of bumper bars 19. The bumper bars 19 can improve the safety of the detection cover 5.

[0030] The friction detection unit 6 is installed inside the detection cover 5 and is used for detecting the friction of the road surface. The friction detection unit 6 includes an electric hydraulic cylinder 61 fixedly inserted at the top of the detection cover 5. The telescopic end of the electric hydraulic cylinder 61 is installed with a detection plate 62. A fixed frame 63 is disposed below the detection plate 62, and a tire 64 is rotatably connected to the bottom of the fixed frame 63. An elastic telescopic component 65 and a pressure transmitter 66 are disposed between the fixed frame 63 and the detection plate 62. A torsion sensor 67 is installed at the bottom of the fixed frame 63, and the detection end of the torsion sensor 67 is in transmission connection with the axle of the tire 64. The electric hydraulic cylinder 61, the pressure transmitter 66, and the torsion sensor 67 are all electrically connected to the controller 2. The elastic telescopic component 65 includes components such as a rod and a spring. The rod is fixed to the top of the fixed frame 63 and is slidably connected to the detection plate 62. The spring is disposed between the detection plate 62 and the fixed frame 63.

[0031] A plurality of detection wheels 7 are all disposed below the mounting plate 4. A plurality of metal teeth 8 are annularly and uniformly distributed on the wheel wall of the detection wheels 7. A plurality of vertical cavities 9 are opened inside the mounting plate 4, and a position detection component 10 is disposed inside each vertical cavity 9. The position detection component 10 is used for measuring the height of the detection wheel 7 and converting the height into an electrical signal and feeding it back to the controller 2. Each position detection component 10 includes a wheel frame 101. The detection wheel 7 is rotatably disposed inside the wheel frame 101. The wheel frame 101 is detachably connected to the bottom of the mounting plate 4. A sliding rod 102 is installed at the top of the wheel frame 101, and the sliding rod 102 is slidably connected to the lower cavity wall of the vertical cavity 9. A ranging probe 103 is inserted at the top of the vertical cavity 9. The ranging probe 103 is used for detecting the height of the top of the sliding rod 102 and converting the height into an electrical signal and feeding it back to the controller 2. The ranging probe 103 emits light and calculates the time required to receive the reflected light to calculate the height of the sliding rod 102.

[0032] The water tank 11 is installed inside the vehicle body 1. A metering and comparison unit 12 is installed on the water tank 11. The controller 2 controls the operation of the metering and comparison unit 12 according to the electrical signal fed back by the position detection component 10, and the controller 2 controls the operation of the friction resistance detection unit 6 according to the difference in the electrical signals fed back by the metering and comparison unit 12. The metering and comparison unit 12 includes a high-pressure water pump 121 fixedly installed outside the water tank 11. The suction end of the high-pressure water pump 121 is communicated with the inside of the water tank 11. A water outlet pipe 122 is installed at the water outlet end of the high-pressure water pump 121. A upper hollow plate 123 is installed on the side wall of the mounting plate 4, and the upper hollow plate 123 is communicated with the water outlet pipe 122. A plurality of left shunt pipes 124 and a plurality of right shunt pipes 125 are fixedly inserted at the bottom of the upper hollow plate 123. A normally open proportional solenoid valve 126 is installed inside each left shunt pipe 124. A normally closed proportional solenoid valve 127 is installed inside each right shunt pipe 125. A liquid flowmeter 128 is installed at the pipe end of each right shunt pipe 125. The controller 2 controls the opening and closing degrees of the corresponding normally open proportional solenoid valve 126 and normally closed proportional solenoid valve 127 according to the electrical signal fed back by the ranging probe 103. The liquid flowmeter 128 is used to detect the liquid flow passing through the inside of the right shunt pipe 125, and the controller 2 controls the operation of the friction resistance detection unit 6 according to the electrical signal fed back by the liquid flowmeter 128. A cleaning component 13 is installed at the front position of the vehicle body 1, and the cleaning component 13 is communicated with the liquid outlet ends of each left shunt pipe 124 and each liquid flowmeter 128. The liquid flowmeter 128 can measure the water liquid flow and feed the value back to the controller 2.

[0033] The cleaning component 13 includes a lower hollow plate 131 fixedly installed on the side wall of the mounting plate 4. The liquid outlet ends of each left shunt pipe 124 and each liquid flowmeter 128 are communicated with the lower hollow plate 131. A liquid delivery pipe 132 is installed on the side wall of the lower hollow plate 131. The liquid delivery pipe 132 passes under the chassis of the vehicle body 1 and is fixedly communicated with a water spraying hollow plate 133. The water spraying hollow plate 133 is detachably connected to the side wall of the front of the vehicle body 1. A plurality of inclined cleaning nozzles 134 are fixedly inserted on the side wall of the water spraying hollow plate 133, which can facilitate the flushing and cleaning of impurities such as sand and gravel on the road surface.

[0034] A flushing shunt pipe 14 is fixedly communicated with the pipe wall of the water outlet pipe 122. The liquid outlet end of the flushing shunt pipe 14 extends into the inside of the detection cover 5. A flushing nozzle 15 is fixedly installed on the inner wall of the detection cover 5, and the liquid outlet end of the flushing nozzle 15 faces the lower side of the side wall of the tire 64. A flushing electric control valve 16 is installed inside the flushing shunt pipe 14. A cleaning electric control valve 17 is installed at the position below the flushing shunt pipe 14 inside the water outlet pipe 122. The flushing electric control valve 16 and the cleaning electric control valve 17 are both electrically connected to the controller 2, which is convenient for flushing and cleaning the tire 64.

[0035] The inlet end of the water outlet pipe 122 is provided with a shell and tube heater 18, and the inlet end of the shell and tube heater 18 is communicated with the outlet end of the high-pressure water pump 121. The shell and tube heater 18 is electrically connected to the controller 2. The shell and tube heater 18 includes components such as inlet end plates (hollow inside) on both sides, a plurality of heating tubes, and heating wires. The water liquid flows through each heating tube through the inlet end plate and is heated by the heating wires in each heating tube.

[0036] The operating principle of the present invention is described as follows: Drive the vehicle body 1 to the road surface to be detected, and then the staff unscrew the bolts on each wheel frame 101 to separate the wheel frame 101 from the bottom of the mounting plate 4. Under the action of gravity, the wheel frame 101 will drive the detection wheel 7 to fall to the ground, and then the detection work of this road surface can be started;

[0037] During the initial detection, the staff starts the controller 2 inside the vehicle. The controller 2 will immediately start a friction coefficient measurement work. At this time, the controller 2 will control the electric hydraulic cylinder 61 to move downward. When the tire 64 touches the ground, when the pressure measuring end of the pressure transmitter 66 detects that the pressure applied by the electric hydraulic cylinder 61 reaches 500 N, the pressure transmitter 66 will feedback an electrical signal to the controller 2. At this time, the controller 2 controls the electric hydraulic cylinder 61 to stop further pressurizing, and the controller 2 will send a voice reminder to the staff inside the vehicle. At this time, the driver can drive the vehicle to start moving, and the moving speed is maintained at 15 mph. Due to the movement of the vehicle body 1, the tire 64 under the detection cover 5 starts to move on the ground. The torque sensor 67 can monitor the torque received by the tire 64 in real time and convert this torque into an electrical signal and feedback it to the controller 2 in real time. The controller 2 will calculate the friction force received by the tire 64 based on this electrical signal. Secondly, the controller 2 will calculate the load size received by the tire 64 based on the electrical signal feedback by the pressure transmitter 66 (since the road surface is not flat, even if the electric hydraulic cylinder 61 applies a pressure of 500 N to the tire 64, during the driving process, the change in the extrusion of the tire 64 by the road surface will still cause the electrical signal feedback by the pressure transmitter 66 to the controller 2 to change). Subsequently, the friction coefficient of this section of the road surface can be calculated. For example, if the controller 2 measures the torque size received by the tire 64 as T based on the electrical signal feedback by the torque sensor 67, the vehicle radius is R, and the friction force received by the tire 64 is F, then through the formula T = R×F, the friction force F received by the tire 64 can be deduced. Subsequently, the controller 2 converts the electrical signal feedback by the pressure transmitter 66 into pressure P, and sets the friction coefficient as U. Then through the formula U×P = F, the friction coefficient U can be deduced. Since the pressure and torque change in real time, therefore, the controller 2 calculates the friction coefficient U once every 3 seconds, and finally calculates the average value to measure the friction coefficient of this section of the road. After the vehicle body 1 moves 100 meters, the controller 2 will control the electric hydraulic cylinder 61 to drive the tire 64 to move upward and reset (wherein, an encoder can be installed at the other end of the wheel axle of the tire 64 to measure the displacement distance of the tire 64. After reaching 100 meters, the controller 2 reminds the personnel that the detection of this section of the road is over);

[0038] Among them, during the initial detection process, since each detection wheel 7 is lowered to contact the ground, when the tire 64 detects this section of the road, under the action of each metal tooth 8, the detection wheel 7 will also rotate synchronously. Since the contact area between the tip of the metal tooth 8 and the ground is small, at the uneven places on the road surface, the height of the detection wheel 7 will be changed through the metal tooth 8, so that the height of the sliding rod 102 can be changed through the wheel frame 101. The controller 2 will control each ranging probe 103 to work. Each ranging probe 103 emits light and calculates the time to receive the reflected light, and then the height of the sliding rod 102 can be measured. The ranging probe 103 converts this height into an electrical signal and feeds it back to the controller 2, and the controller 2 controls the opening and closing degrees of the valve plates of the corresponding normally open proportional solenoid valve 126 and normally closed proportional solenoid valve 127 according to this electrical signal. The higher the height of the sliding rod 102, the smaller the opening degree of the valve plate of the normally open proportional solenoid valve 126, and the larger the opening degree of the normally closed proportional solenoid valve 127. After the controller 2 is started, it will control the high-pressure water pump 121 to work. The high-pressure water pump 121 can pump out the water inside the water tank 11 and transport it to the inside of the upper hollow plate 123 through the water outlet pipe 122. Since the opening degrees of the normally open proportional solenoid valve 126 and the normally closed proportional solenoid valve 127 change synchronously based on the height of the sliding rod 102 detected by the ranging probe 103, the water flow rates passing through each liquid flowmeter 128 also change synchronously. Therefore, within the first 100 meters of initial movement, the values measured by each liquid flowmeter 128 represent the roughness values of this section of the road, and the controller 2 records the value measured by the liquid flowmeter 128 at this time as A1;

[0039] After the detection of the initial 100-meter section is completed, the controller 2 clears the values measured by each liquid flowmeter 128. At the same time, the driver can increase the vehicle's moving speed to 30 mph. During this process, each detection wheel 7 and the metal teeth 8 can continue to detect the roughness of the road surface, and the liquid flowmeter 128 continues to measure the roughness of the road surface. After 8 seconds, the controller 2 records the measured values of each liquid flowmeter 128 as A2, and clears them again and repeats, so as to obtain A3, A4, A5... At the same time, compare A2 with A1 to determine whether the difference between the two exceeds the threshold (this threshold can be set according to the requirements for the difference in road surface roughness. For example, the threshold is set to 1.5L, that is, when the measured difference between A2 and A1 exceeds 1.5L, it indicates that there is an obvious difference in the roughness of the road surface). When the difference in road surface roughness is small, the friction coefficient of the road surface is also similarly small. Therefore, there is no need to repeat the friction coefficient measurement for this section of the road. However, when the difference in road surface roughness is large, the friction coefficient of the road surface also shows a large difference. Therefore, when the difference between A2 and A1 exceeds the threshold, it is necessary to measure the friction coefficient of the current section of the road. The measurement method is the same as described above. By applying a load to the tire 64 and measuring the torque of the tire 64, the friction coefficient is calculated. When the difference between A2 and A1 is within the threshold range, after the controller 2 obtains the value of A3, it calculates the difference between A3 and A1 until the difference between the flow value corresponding to a certain section of the road and A1 exceeds the threshold. The controller 2 will issue a voice reminder. At this time, the personnel should stop the vehicle in time and measure the friction coefficient of the current section of the road (wherein, each time the friction coefficient of a section of the road is measured, the value measured by the liquid flowmeter 128 during the detection of the current section of the road needs to be re-recorded as A1 for subsequent comparison of the road surface roughness. By measuring the friction coefficient of different sections of the road with large roughness differences, unnecessary friction coefficient measurements can be reduced, the vehicle speed can be increased, the detection efficiency can be improved, and the wear of the tire 64 can be reduced. Secondly, since the sliding rod 102 can freely slide inside the vertical cavity 9, the acting force when the metal teeth 8 and the detection wheel 7 contact the ground is small, and the wear degree of the metal teeth 8 is small. Therefore, there is no need to frequently replace spare parts);

[0040] The water liquid discharged through the left shunt pipe 124 and the right shunt pipe 125 will enter the water spraying hollow plate 133 through the lower hollow plate 131 and the infusion pipe 132, and finally be sprayed out through each cleaning nozzle 134. The sprayed water liquid can wash away impurities such as sand and gravel on the road surface, thereby avoiding the influence of sundries on the accuracy of the measurement of the road surface roughness and friction coefficient;

[0041] Secondly, after each friction coefficient detection operation, when the electric hydraulic cylinder 61 drives the tire 64 to move upward and reset, the controller 2 will control the flushing electric control valve 16 to be energized and opened, and control the cleaning electric control valve 17 to be energized and closed. At this time, the water in the water outlet pipe 122 will be sprayed out from the flushing nozzle 15 through the flushing shunt pipe 14. The sprayed water will impact the surface of the tire 64. Under the impact force, the tire 64 will rotate, so that the water flow can be used to clean the sundries such as sand and gravel that may exist on the surface of the tire 64, avoiding affecting the accuracy of the friction coefficient measurement of the subsequent road section. The flushing time is 20 seconds. Secondly, before each friction coefficient detection operation, the controller 2 will also control the flushing electric control valve 16 to open, and control the cleaning electric control valve 17 to close. At the same time, it will also control the shell and tube heater 18 to work. The shell and tube heater 18 can heat the water entering the water outlet pipe 122, and the heating temperature is 80°C. The heated water will also heat the tire 64, so as to simulate the temperature of the tire 64 when the vehicle is running. Since the rubber material of the tire 64 will become soft after the temperature of the tire 64 rises, which will affect the friction coefficient between the tire and the ground. Therefore, by heating the tire (the heating temperature of the shell and tube is 80°C, and due to the loss of heat conduction, the temperature of the tire 64 is about 40°C to 50°C), the measured friction coefficient can be more in line with the actual situation, and the tire 64 can be kept at a relatively stable detection temperature, reducing the impact of temperature difference on the stability of the detection result. The heating and flushing time is 1 minute.

[0042] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A road friction coefficient detection device for highway pavement detection, comprising a vehicle body (1) and a controller (2) arranged inside the vehicle body (1). A detachable mounting bracket (3) is installed at the tail of the vehicle body (1). The mounting bracket (3) is provided with a mounting plate (4), and a detection cover (5) is installed on the side wall of the mounting plate (4), characterized in that, It further includes: A friction resistance detection unit (6), installed inside the detection cover (5) for detecting the friction resistance of the road surface; A plurality of detection wheels (7), all arranged below the mounting plate (4). A plurality of metal teeth (8) are evenly distributed in a ring on the wheel wall of the detection wheel (7). A plurality of vertical cavities (9) are opened inside the mounting plate (4), and a position detection component (10) is arranged inside each vertical cavity (9). The position detection component (10) is used to measure the height of the detection wheel (7) and convert the height into an electrical signal and feedback it to the controller (2); A water tank (11), installed inside the vehicle body (1). The water tank (11) is equipped with a metering and comparison unit (12). The controller (2) controls the metering and comparison unit (12) to work according to the electrical signal feedback by the position detection component (10), and the controller (2) controls the friction resistance detection unit (6) to work according to the electrical signal difference feedback by the metering and comparison unit (12); Each of the position detection components (10) includes a wheel frame (101). The detection wheel (7) is rotatably arranged inside the wheel frame (101). A sliding rod (102) is installed at the top of the wheel frame (101), and the sliding rod (102) is slidably connected to the lower cavity wall of the vertical cavity (9). A ranging probe (103) is inserted into the top of the vertical cavity (9). The ranging probe (103) is used to detect the height of the top of the sliding rod (102) and convert the height into an electrical signal and feedback it to the controller (2); The metering and comparison unit (12) includes a high-pressure water pump (121) fixedly installed outside the water tank (11). The suction end of the high-pressure water pump (121) is communicated with the inside of the water tank (11). The water outlet end of the high-pressure water pump (121) is installed with a water outlet pipe (122). The side wall of the mounting plate (4) is installed with an upper hollow plate (123), and the upper hollow plate (123) is communicated with the water outlet pipe (122). A plurality of left shunt pipes (124) and a plurality of right shunt pipes (125) are fixedly inserted at the bottom of the upper hollow plate (123). A normally open proportional solenoid valve (126) is installed inside each of the left shunt pipes (124). A normally closed proportional solenoid valve (127) is installed inside each of the right shunt pipes (125). A liquid flowmeter (128) is installed at the pipe end of each of the right shunt pipes (125). The controller (2) controls the opening and closing degrees of the corresponding normally open proportional solenoid valve (126) and normally closed proportional solenoid valve (127) according to the electrical signal feedback by the ranging probe (103). The liquid flowmeter (128) is used to detect the liquid flow passing through the inside of the right shunt pipe (125), and the controller (2) controls the friction resistance detection unit (6) to work according to the electrical signal feedback by the liquid flowmeter (128).

2. The road friction coefficient detection device for highway pavement detection according to claim 1, characterized in that, The friction detection unit (6) includes an electric hydraulic cylinder (61) fixedly inserted at the top of the detection cover (5). A detection plate (62) is installed at the telescopic end of the electric hydraulic cylinder (61). A fixed frame (63) is arranged below the detection plate (62), and a tire (64) is rotatably connected to the bottom of the fixed frame (63). An elastic telescopic component (65) and a pressure transmitter (66) are arranged between the fixed frame (63) and the detection plate (62). A torsion sensor (67) is installed at the bottom of the fixed frame (63), and the detection end of the torsion sensor (67) is in transmission connection with the axle of the tire (64). The electric hydraulic cylinder (61), the pressure transmitter (66), and the torsion sensor (67) are all electrically connected to the controller (2).

3. The road friction coefficient detection device for highway pavement detection according to claim 1, characterized in that, The wheel frame (101) is detachably connected to the bottom of the mounting plate (4).

4. A road friction coefficient detection device for highway pavement detection according to claim 1, characterized in that, A cleaning component (13) is installed at the front of the vehicle body (1), and the cleaning component (13) is communicated with the liquid outlet ends of each left shunt pipe (124) and each liquid flowmeter (128).

5. The road friction coefficient detection device for highway pavement detection according to claim 4, characterized in that, The cleaning component (13) includes a lower hollow plate (131) fixedly installed on the side wall of the mounting plate (4). The liquid outlet ends of each left shunt pipe (124) and each liquid flowmeter (128) are all communicated with the lower hollow plate (131). A liquid delivery pipe (132) is installed on the side wall of the lower hollow plate (131), and the liquid delivery pipe (132) passes under the chassis of the vehicle body (1) and is fixedly communicated with a water spraying hollow plate (133). The water spraying hollow plate (133) is detachably connected to the side wall of the front of the vehicle body (1). A plurality of inclined cleaning nozzles (134) are fixedly inserted on the side wall of the water spraying hollow plate (133).

6. The road friction coefficient detection device for highway pavement detection according to claim 2, characterized in that, A flushing shunt pipe (14) is fixedly communicated with the pipe wall of the water outlet pipe (122), and the liquid outlet end of the flushing shunt pipe (14) extends into the detection cover (5). A flushing nozzle (15) is fixedly installed on the inner wall of the detection cover (5), and the liquid outlet end of the flushing nozzle (15) faces the lower side of the side wall of the tire (64). A flushing electric control valve (16) is installed inside the flushing shunt pipe (14). A cleaning electric control valve (17) is installed at a position below the flushing shunt pipe (14) inside the water outlet pipe (122). The flushing electric control valve (16) and the cleaning electric control valve (17) are both electrically connected to the controller (2).

7. A road friction coefficient detection device for highway pavement detection according to claim 1, characterized in that, A shell-and-tube heater (18) is installed at the water inlet end of the water outlet pipe (122), and the water inlet end of the shell-and-tube heater (18) is communicated with the water outlet end of the high-pressure water pump (121). The shell-and-tube heater (18) is electrically connected to the controller (2).

8. The road friction coefficient detection device for highway pavement detection according to claim 1, characterized in that, Two groups of symmetric bumpers (19) are installed at the rear of the vehicle body (1), and the detection cover (5) is arranged between the two groups of bumpers (19).

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