Air suspension control system based on ultrasonic measurement and control device

Abstract

The air suspension control system based on the ultrasonic measurement and control device comprises a height adjusting device, an ultrasonic measurement module, a temperature sensor and a controller, and the height adjusting device is used for adjusting the distance between a suspension supporting arm and a vehicle body; the ultrasonic measurement module is used for transmitting an ultrasonic pulse signal and receiving a reflected wave echo signal; the temperature sensor is used for collecting environment temperature; the controller is electrically connected with the ultrasonic measuring module to obtain ultrasonic transmitting time and ultrasonic returning time, calculates transit time based on the ultrasonic transmitting time and the ultrasonic returning time, is electrically connected with the temperature sensor to receive environment temperature, calculates ultrasonic real-time speed based on the environment temperature, and sends the ultrasonic real-time speed to the ultrasonic measuring module. The suspension height is calculated based on the ultrasonic real-time speed and the transit time, and the controller controls the height adjusting device to adjust the distance between the suspension supporting arm and the vehicle body based on the evaluation result of the suspension height.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle suspension height control devices, and in particular to an air suspension control system based on an ultrasonic measurement and control device. Background Art

[0002] The automobile suspension system is an assembly of related devices that ensures that there is an elastic connection between the wheels and the automobile load-bearing system and can transmit loads, mitigate impacts, attenuate vibrations, and adjust the position of the vehicle body during driving. Some high-end models use air suspension systems to support the vehicle body, reduce the impact of the road on the vehicle body, improve driving experience, and ensure normal driving of the vehicle. It is necessary to sense the height of the vehicle body through the sensing part height sensor. According to the output signal of the height sensor, the control system determines the change in the height of the vehicle body and issues instructions to control the compressor and the air pressure distribution valve to inflate or deflate the air spring, so that the air spring is extended or compressed, thereby adjusting the height change of the vehicle, so that the vehicle has excellent comfort, handling stability and passability.

[0003] At present, the vehicle height sensor mainly adopts mechanical contact distance measurement. The up and down movement of the wheel is transmitted to the sensor through the movement of the control arms on the front and rear axles and the mechanical rotation of the sensor connecting rod. The general working environment of the car chassis is full of dirt, gravel and other impurities, especially when driving on muddy roads. It is easy to cause the sensor connecting rod to get stuck, affecting the measurement precision and accuracy. The existing technology has a complex intermediate mechanical structure, many connecting rods, and many transmission links, resulting in large measurement errors and poor anti-interference ability, which leads to poor accuracy of the existing air suspension system. In addition, the existing sensors and control systems are expensive. Summary of the invention

[0004] To solve at least one aspect of the above problems, the present invention provides an air suspension control system based on an ultrasonic measurement and control device, comprising: a height adjustment device, an ultrasonic measurement module, a temperature sensor and a controller, wherein the height adjustment device is arranged between a suspension support arm and a vehicle body, and the height adjustment device is used to adjust the distance between the suspension support arm and the vehicle body; the ultrasonic measurement module is used to transmit ultrasonic pulse signals and receive reflected wave echo signals, and the ultrasonic measurement module is fixedly arranged between the bottom of the vehicle body and the suspension; the temperature sensor is arranged at the bottom of the vehicle body, and the temperature sensor is used to collect ambient temperature; the controller is electrically connected to the ultrasonic measurement module to obtain ultrasonic emission time and ultrasonic return time, and calculates the transit time based on the ultrasonic emission time and ultrasonic return time, the controller is electrically connected to the temperature sensor to receive the ambient temperature, the controller calculates the ultrasonic real-time speed based on the ambient temperature, and calculates the suspension height based on the ultrasonic real-time speed and the transit time, the controller also includes a target height, and the target height is used to evaluate the suspension height, the controller is electrically connected to the height adjustment device, and the controller controls the height adjustment device to adjust the distance between the suspension support arm and the vehicle body based on the evaluation result of the suspension height.

[0005] Preferably, the height adjustment device includes an air compressor, an air pressure distribution valve and an air spring, and the controller is electrically connected to the air compressor and the air pressure distribution valve. When the suspension height is greater than the target height, the controller controls the air compressor and the air pressure distribution valve to deflate the air spring. When the suspension height is less than the target height, the controller controls the air compressor and the air pressure distribution valve to inflate the air spring.

[0006] Preferably, the height adjustment device also includes an electronically controlled shock absorber, which is arranged between the air spring and the suspension support arm, and the controller is electrically connected to the electronically controlled shock absorber, and the controller adjusts the damping of the electronically controlled shock absorber based on the evaluation result of the suspension height.

[0007] Preferably, the controller also includes a preset height threshold, which includes a maximum threshold and a minimum threshold. The target height is less than the maximum threshold and greater than the minimum threshold. When the suspension height is greater than the maximum threshold, or the suspension height is less than the minimum threshold, the controller outputs an alarm signal and locks the height adjustment device.

[0008] Preferably, it further comprises an audible and visual alarm module, the controller is electrically connected to the audible and visual alarm module, and the audible and visual alarm module outputs audible and visual alarm information in response to the alarm signal.

[0009] Preferably, the ultrasonic measurement module further includes an ultrasonic timer, and the controller initializes the ultrasonic timer in response to a vehicle power-on signal.

[0010] Preferably, it further comprises a display, and the display is electrically connected to the controller.

[0011] Preferably, it also includes a threshold setting module, which includes a threshold increasing unit, a threshold decreasing unit and a threshold setting unit. The controller includes a threshold control unit, which is electrically connected to the threshold increasing unit, the threshold decreasing unit and the threshold setting unit respectively. The threshold increasing unit is used to input an increasing threshold, and the threshold decreasing unit is used to input a decreasing threshold. The threshold control unit includes a limit boundary value. The threshold control unit evaluates the increasing threshold and the decreasing threshold based on the limit boundary value. When the increasing threshold and the decreasing threshold are qualified, the threshold control unit updates the preset height threshold in response to a confirmation signal.

[0012] Preferably, it further comprises a power supply unit, and the power supply unit is electrically connected to the controller.

[0013] Preferably, it also includes an installation shell, which is set to be arranged at the bottom of the vehicle body, the controller and the power supply are fixedly arranged in the installation shell, the ultrasonic measurement module is fixedly connected to the lower surface of the installation shell, the temperature sensor and the sound and light alarm module are fixedly arranged on the shell, and the threshold increase unit, the threshold reduction unit and the threshold setting unit adopt a button structure and are arranged on the installation shell.

[0014] The air suspension control system based on the ultrasonic measurement and control device of the embodiment of the present invention has the following beneficial effects: the ultrasonic measurement module is used as a non-contact distance measurement with high measurement accuracy and low noise, and has green characteristics, low cost and strong anti-interference ability. At the same time, the ambient temperature is collected through the temperature sensor, and the ambient temperature is used to calculate the suspension height to improve the calculation accuracy and optimize the suspension control system; on the other hand, the visualization of the suspension control process is improved through the sound and light alarm function and display function. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to better understand the above and other purposes, features, advantages and functions of the present invention, reference may be made to the embodiments shown in the accompanying drawings. The same reference numerals in the accompanying drawings refer to the same components. It should be understood by those skilled in the art that the accompanying drawings are intended to schematically illustrate the preferred embodiments of the present invention and have no limiting effect on the scope of the present invention, and the components in the drawings are not drawn to scale.

[0016] Figure 1A structural block diagram of an air suspension control system based on an ultrasonic measurement and control device according to an embodiment of the present invention is shown;

[0017] Figure 2 A schematic diagram of an application scenario based on an ultrasonic measurement and control device according to an embodiment of the present invention is shown;

[0018] Figure 3 It shows a schematic structural diagram of an installation housing and a connection module thereof based on an ultrasonic measurement and control device according to an embodiment of the present invention;

[0019] Figure 4 A schematic diagram of an application scenario flow of an air suspension control system based on an ultrasonic measurement and control device according to an embodiment of the present invention is shown;

[0020] Figure 5 A schematic diagram of an application scenario flow of a threshold setting module of an air suspension control system based on an ultrasonic measurement and control device according to an embodiment of the present invention is shown.

[0021] Reference numerals:

[0022] 1. Car body; 2. Suspension support arm; 3. Wheel; 4. Air spring; 5. Electronically controlled shock absorber; 6. Ultrasonic transmitting unit; 7. Ultrasonic receiving unit; 8. Mounting shell; 9. Sound and light alarm module; 10. Temperature sensor; 11. Controller; 12. Threshold setting module; 13. Display; 14. Power supply unit. DETAILED DESCRIPTION

[0023] The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0024] As used herein, the term "including" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "based at least in part on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0025] In order to at least partially solve one or more of the above problems and other potential problems, an embodiment of the present disclosure proposes an air suspension control system based on an ultrasonic measurement and control device, including: a height adjustment device, an ultrasonic measurement module, a temperature sensor and a controller, wherein the height adjustment device is arranged between the suspension support arm and the vehicle body, and the height adjustment device is used to adjust the distance between the suspension support arm and the vehicle body; the ultrasonic measurement module is used to transmit ultrasonic pulse signals and receive reflected wave echo signals, and the ultrasonic measurement module is fixedly arranged between the bottom of the vehicle body and the suspension; the temperature sensor is arranged at the bottom of the vehicle body, and the temperature sensor is used to collect ambient temperature; the controller is electrically connected to the ultrasonic measurement module to obtain ultrasonic emission time and ultrasonic return time, and calculates the transit time based on the ultrasonic emission time and the ultrasonic return time, the controller is electrically connected to the temperature sensor to receive the ambient temperature, the controller calculates the ultrasonic real-time speed based on the ambient temperature, and calculates the suspension height based on the ultrasonic real-time speed and the transit time, the controller also includes a target height, and the target height is used to evaluate the suspension height, the controller is electrically connected to the height adjustment device, and the controller controls the height adjustment device to adjust the distance between the suspension support arm and the vehicle body based on the evaluation result of the suspension height.

[0026] Specifically, Figure 2 As shown, the height adjustment device is arranged between the vehicle body 1 and the suspension support arm 2, and the height adjustment device adopts a height adjustment device of the prior art, such as a hydraulic adjustment device, an air spring adjustment device, etc.

[0027] like Figure 1 and Figure 2 As shown, the ultrasonic measurement module includes an ultrasonic transmitting unit 6 and an ultrasonic receiving unit 7. The ultrasonic transmitting unit 6 is used to transmit ultrasonic pulse signals, and the ultrasonic receiving unit 7 is used to receive reflected wave echo signals. 40khz ultrasonic waves are used. It has beam-forming and directivity. The higher the frequency of the ultrasonic wave, the stronger the directivity. The higher the frequency of the ultrasonic wave, the shorter the wavelength. The wavelength can be as small as the size of the ultrasonic propagation medium material. Ultrasonic waves have strong directivity, slow energy consumption, strong anti-interference ability, and can propagate farther in the medium. Non-contact ranging with high measurement accuracy. Ultrasonic waves are inaudible, so noise is avoided, and thus ultrasound has green characteristics. Ultrasonic products have the advantages of low price and easy hardware implementation. In addition, they have strong penetrating ability, are not affected by electromagnetic effects, and are not affected by environmental factors such as dust, soil, gravel and other impurities, and have good anti-interference ability.

[0028] The temperature sensor can be any existing pressure temperature sensor, resistance temperature sensor, thermistor sensor, thermocouple sensor, etc., which can collect the ambient temperature in real time. The temperature sensor is electrically connected to the controller and outputs the collected ambient temperature.

[0029] The controller uses STC89C52 single-chip microcomputer, which has low power consumption, high performance, and parallel address bus, data bus, and control bus. These pins are used to expand parallel peripheral devices and can be connected to the single-chip microcomputer through the serial port to control and coordinate the work of each module unit.

[0030] like Figure 2 As shown, when the wheel 3 moves up and down, the suspension support arm 2 will move with it, thereby causing the distance between the vehicle body 1 and the suspension support arm 2 to change, and the distance change can be measured at all times through ultrasound. The ultrasonic pulse signal is sent out by the ultrasonic transmitting unit 6 and reaches the suspension support arm 2 and then reflects. The reflected wave echo signal is received by the ultrasonic receiving unit 7. In some embodiments, the controller obtains the ultrasonic emission time through the ultrasonic transmitting unit 6, and the controller obtains the ultrasonic return time through the ultrasonic receiving unit 7. The controller determines the transit time t by calculating the time difference between the ultrasonic emission time and the ultrasonic return time, calculates the ultrasonic propagation distance according to the ultrasonic propagation speed and propagation time, and further calculates the suspension height. Specifically, the ultrasonic real-time speed c is calculated based on the relationship between the ultrasonic propagation speed in the air and the ambient temperature, then:

[0031]

[0032] Where c0 is the speed of sound 331.4 m / s, and T is the ambient temperature. Further, the suspension height is calculated based on the real-time speed and transit time of the ultrasonic wave, and then:

[0033]

[0034] Wherein, D is the suspension height, c is the real-time speed of the ultrasonic wave, and t is the transit time. Further, the controller evaluates the suspension height based on a preset target height. When the suspension height is greater than the target height, the controller controls the height adjustment device to lower the height. When the suspension height is less than the target height, the controller controls the height adjustment device to increase the height. In some embodiments, Figure 1 As shown, the height adjustment device includes an air compressor, an air pressure distribution valve and an air spring. The controller is electrically connected to the air compressor and the air pressure distribution valve. When the suspension height is greater than the target height, the controller controls the air compressor and the air pressure distribution valve to deflate the air spring. When the suspension height is less than the target height, the controller controls the air compressor and the air pressure distribution valve to inflate the air spring.

[0035] In some embodiments, the height adjustment device also includes an electronically controlled shock absorber, which is arranged between the air spring and the suspension support arm. The controller is electrically connected to the electronically controlled shock absorber, and the controller adjusts the damping of the electronically controlled shock absorber based on the evaluation result of the suspension height.

[0036] Specifically, Figure 1 and Figure 2 As shown, the top end of the air spring 4 is connected to the vehicle body, and the electronically controlled shock absorber 5 is arranged between the bottom end of the air spring 4 and the suspension support arm 2. The controller reduces the vibration of the vehicle body 1 during the travel process by adjusting the damping of the electronically controlled shock absorber 5.

[0037] In some embodiments, the controller also includes a preset height threshold, which includes a maximum threshold and a minimum threshold. The target height is less than the maximum threshold and greater than the minimum threshold. When the suspension height is greater than the maximum threshold, or the suspension height is less than the minimum threshold, the controller outputs an alarm signal and locks the height adjustment device.

[0038] Specifically, the preset height threshold is used to evaluate the status of the height adjustment device. When the suspension height is greater than the maximum threshold, or the suspension height is less than the minimum threshold, the height adjustment device is judged to be in a fault state, and an alarm signal is output to warn, and the height adjustment device is locked at the same time to prevent further adjustment operations from aggravating the fault state and causing an accident.

[0039] In some embodiments, a sound and light alarm module is also included, the controller is electrically connected to the sound and light alarm module, and the sound and light alarm module outputs sound and light alarm information in response to the alarm signal.

[0040] Specifically, the sound and light alarm includes a light emitting diode and a loudspeaker, etc. The controller outputs a light alarm signal by controlling the color or brightness of the light emitting diode, and outputs a sound alarm by controlling the loudspeaker to play a preset audio.

[0041] In some embodiments, the ultrasonic measurement module further includes an ultrasonic timer, and the controller initializes the ultrasonic timer in response to a vehicle power-on signal.

[0042] Specifically, Figure 1 As shown, the ultrasonic timer of the ultrasonic measurement module is used to collect the ultrasonic emission time and the ultrasonic return time. The controller obtains the ultrasonic emission time and the ultrasonic return time by connecting to the ultrasonic timer.

[0043] like Figure 4 As shown, the execution steps of the air suspension height control system based on the ultrasonic measurement control device are as follows:

[0044] Step T1, the car is started.

[0045] Step T2, initializing the timer of the ultrasonic measurement control device.

[0046] Step T3, ultrasonic measurement control device temperature reading.

[0047] Step T4, the ultrasonic measurement control device starts ultrasonic distance measurement, the ultrasonic transmitting module emits 40khz ultrasonic waves, the ultrasonic waves are reflected back by the control arm, and are obtained by the ultrasonic receiving module to calculate the distance.

[0048] Step T5, refresh the display.

[0049] Step T6: Threshold setting: The preset height threshold can be set as needed.

[0050] Step T7, threshold judgment: A judgment is made according to the set threshold. If the suspension height exceeds the preset height threshold, the sound and light alarm module is activated to give an alarm prompt and the display is displayed on the screen, and the height adjustment function is turned off by locking the height adjustment device.

[0051] Step T8: determine whether the measured height is equal to the designed height within the threshold range.

[0052] Step T9: if the measured height is greater than the designed height (ie, the target height), the air compressor and the air pressure distribution valve are controlled to deflate the air spring.

[0053] Step T10, if the measured height is less than the designed height (ie, the target height), control the air compressor and the air pressure distribution valve to inflate the air spring.

[0054] Step T11, if the measured height is equal to the designed height, the height reaches the target value, and the process ends.

[0055] In some embodiments, a display is also included, and the display is electrically connected to the controller.

[0056] Specifically, Figure 1 and Figure 3 As shown, the display 13 can display the calculated measurement data at any time, so that the measurer can obtain the data more intuitively.

[0057] In some embodiments, a threshold setting module is also included, the threshold setting module includes a threshold increasing unit, a threshold decreasing unit and a threshold setting unit, the controller includes a threshold control unit, the threshold control unit is electrically connected to the threshold increasing unit, the threshold decreasing unit and the threshold setting unit respectively, the threshold increasing unit is used to input the increasing threshold, the threshold decreasing unit is used to input the decreasing threshold, the threshold control unit includes a limit boundary value, the threshold control unit evaluates the increasing threshold and the decreasing threshold based on the limit boundary value, when the increasing threshold and the decreasing threshold are qualified, the threshold control unit updates the preset height threshold in response to the confirmation signal.

[0058] Specifically, the threshold increasing unit uses an increasing key, the threshold decreasing unit uses a decreasing key, and the threshold setting unit uses a setting key, and the input of the threshold value and the confirmation signal is performed by clicking each key. Figure 5As shown, the operation steps of the threshold setting module include:

[0059] Step S1, the car is started, and the threshold setting module is started in response to the power-on signal of the vehicle.

[0060] Step S2, initializing the timer of the ultrasonic measurement control device.

[0061] Step S3, press the set key.

[0062] Step S3, entering the setting interface, the controller outputs a preset setting interface through the display in response to the received setting key input signal.

[0063] Step S4, press the increase key to set the threshold increase value.

[0064] Step S5, press the decrease key to set the threshold decrease value.

[0065] Step S6, displaying the setting value, the controller outputs the setting value through the display in response to the operation of the increase key or the decrease key.

[0066] Step S7, press the set key to confirm the set value. The controller uses the preset limit boundary value to ensure that the threshold increase and decrease values ​​can only be within the set boundary.

[0067] S8. Return.

[0068] In some embodiments, a power supply unit is also included, and the power supply unit is electrically connected to the controller.

[0069] Specifically, Figure 1 and Figure 3 As shown, the power supply unit 14 supplies power to the display 13 , the sound and light alarm module 9 and the ultrasonic measurement module through the controller 11 .

[0070] In some embodiments, it also includes an installation shell, which is set at the bottom of the vehicle body, the controller and the power supply are fixedly set in the installation shell, the ultrasonic measurement module is fixedly connected to the lower surface of the installation shell, the temperature sensor and the sound and light alarm module are fixedly set on the shell, and the threshold increase unit, the threshold reduction unit and the threshold setting unit adopt a button structure and are set on the installation shell.

[0071] Specifically, Figure 3 As shown, the vehicle body 1 and multiple functional modules of the air suspension control system based on the ultrasonic measurement and control device are fixedly connected through the mounting shell 8. The mounting shell 8 is provided with multiple openings, so that each button of the temperature sensor 10, the sound and light alarm module 9, the ultrasonic measurement module, the display 13, and the threshold setting module 12 at least partially protrudes out of the mounting shell 8.

[0072] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the present invention.

Claims

1. An air suspension control system based on an ultrasonic measurement and control device, characterized in that: include: A height adjustment device, the height adjustment device is arranged between the suspension support arm and the vehicle body, and the height adjustment device is used to adjust the distance between the suspension support arm and the vehicle body; An ultrasonic measurement module, which is used to transmit ultrasonic pulse signals and receive reflected wave echo signals, and is fixedly arranged between the bottom of the vehicle body and the suspension; A temperature sensor, the temperature sensor is arranged at the bottom of the vehicle body, and the temperature sensor is used to collect the ambient temperature; A controller, the controller is electrically connected to the ultrasonic measurement module to obtain the ultrasonic emission time and the ultrasonic return time, and calculates the transit time based on the ultrasonic emission time and the ultrasonic return time. The controller is electrically connected to the temperature sensor to receive the ambient temperature. The controller calculates the ultrasonic real-time speed based on the ambient temperature, and calculates the suspension height based on the ultrasonic real-time speed and the return time. The controller also includes a target height, and the target height is used to evaluate the suspension height. The controller is electrically connected to the height adjustment device, and the controller controls the height adjustment device to adjust the distance between the suspension support arm and the vehicle body based on the evaluation result of the suspension height.

2. The system according to claim 1, characterized in that The height adjustment device includes an air compressor, an air pressure distribution valve and an air spring. The controller is electrically connected to the air compressor and the air pressure distribution valve. When the suspension height is greater than the target height, the controller controls the air compressor and the air pressure distribution valve to deflate the air spring. When the suspension height is less than the target height, the controller controls the air compressor and the air pressure distribution valve to inflate the air spring.

3. The system according to claim 2, characterized in that The height adjustment device further includes an electronically controlled shock absorber, which is disposed between the air spring and the suspension support arm. The controller is electrically connected to the electronically controlled shock absorber, and the controller adjusts the damping of the electronically controlled shock absorber based on the evaluation result of the suspension height.

4. The system according to claim 1, characterized in that The controller also includes a preset height threshold, which includes a maximum threshold and a minimum threshold. The target height is less than the maximum threshold and greater than the minimum threshold. When the suspension height is greater than the maximum threshold, or the suspension height is less than the minimum threshold, the controller outputs an alarm signal and locks the height adjustment device.

5. The system according to claim 4, characterized in that: It also includes an audible and visual alarm module, the controller is electrically connected to the audible and visual alarm module, and the audible and visual alarm module outputs audible and visual alarm information in response to the alarm signal.

6. The system according to claim 5, characterized in that The ultrasonic measurement module further includes an ultrasonic timer, and the controller initializes the ultrasonic timer in response to a vehicle power-on signal.

7. The system according to claim 6, characterized in that A display is also included, and the display is electrically connected to the controller.

8. The system according to claim 7, characterized in that It also includes a threshold setting module, which includes a threshold increasing unit, a threshold decreasing unit and a threshold setting unit. The controller includes a threshold control unit, which is electrically connected to the threshold increasing unit, the threshold decreasing unit and the threshold setting unit respectively. The threshold increasing unit is used to input an increasing threshold, and the threshold decreasing unit is used to input a decreasing threshold. The threshold control unit includes a limit boundary value. The threshold control unit evaluates the increasing threshold and the decreasing threshold based on the limit boundary value. When the increasing threshold and the decreasing threshold are qualified, the threshold control unit updates the preset height threshold in response to a confirmation signal.

9. The system according to claim 8, characterized in that It also includes a power supply unit, which is electrically connected to the controller.

10. The system according to claim 9, characterized in that It also includes an installation shell, which is set to be arranged at the bottom of the vehicle body, the controller and the power supply are fixedly arranged in the installation shell, the ultrasonic measurement module is fixedly connected to the lower surface of the installation shell, the temperature sensor and the sound and light alarm module are fixedly arranged on the shell, and the threshold increase unit, the threshold reduction unit and the threshold setting unit adopt a button structure and are arranged on the installation shell.

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