Vehicle braking noise measuring system and method based on EtherCAT bus

Abstract

The invention discloses a vehicle braking noise measurement system and method based on an EtherCAT bus. The system comprises a power supply system, an EtherCAT controller, a signal acquisition system and a man-machine interaction system. The method comprises the steps that a brake pressure threshold PTh is set, the brake pressure Pb is set through the pressure sensor, and when Pb is larger than or equal to PTh, the controller collects sound pressure, vibration, temperature, pressure, environment temperature and humidity, vehicle speed and vehicle deceleration signals; when Pb is smaller than PTh, the controller stops collecting; the controller processes the collected sound pressure signal to obtain a peak value Lps and a frequency Fps of a sound pressure signal frequency spectrum; processing the four groups of collected vibration signals to obtain peak values and frequencies Fpv1, Fpv2, Fpv3 and Fpv4 of frequency spectrums of the four groups of vibration signals; if the Fps is the same as any one or more of the vibration frequencies, it is judged that braking noise is generated in the braking process. According to the invention, high-speed and efficient communication is realized through the EtherCAT bus technology, the data synchronization of each sensor is ensured, and the measurement precision is improved.

Description

Technical Field

[0001] The invention relates to a vehicle brake noise test, and in particular to a vehicle brake noise measurement system and a vehicle brake noise measurement method based on an EtherCAT bus, which can realize automatic recording, storage, analysis and judgment of vehicle brake noise. Background Art

[0002] When a vehicle brakes, the brake noise generated by friction vibration has many hazards. Braking noise will reduce the riding experience of drivers and passengers. Especially when the noise is loud or the frequency is high, it will cause discomfort to passengers, can make the driver irritable and fatigued, and then affect the driver's attention and reaction speed, and increase the risk of traffic accidents. At the same time, braking noise is one of the important sources of urban noise pollution, causing interference to the daily life of surrounding residents. In addition, long-term vibration and noise may cause damage and failure of brake system components, which will lead to more serious safety problems.

[0003] With increasingly stringent environmental regulations, reducing vehicle noise has become an issue that the automotive industry must face. Measuring brake noise is one of the important means to control vehicle noise and meet environmental protection requirements. By measuring brake noise, the performance and stability of the brake system can be evaluated, providing a basis for the design, optimization and improvement of the brake system. At present, the vehicle brake noise measurement system has a complex structure, low system integration, and weak data synchronization, which greatly limits the testing, analysis and subsequent research of brake noise. Summary of the invention

[0004] Aiming at the problems of complex structure, low integration and poor data synchronization of the existing vehicle brake noise measurement system, the present invention proposes a vehicle brake noise measurement system and a measurement method based on EtherCAT bus.

[0005] The technical solution of the present invention is as follows:

[0006] A vehicle brake noise measurement system based on EtherCAT bus, characterized by: comprising a power supply system, a main controller, a signal acquisition system and a human-computer interaction system;

[0007] The power supply system provides power to the main controller; the signal acquisition system is connected to the main controller via a signal transmission bus; and the human-computer interaction system is connected to the main controller via a data bus.

[0008] The main controller is composed of an EtherCAT controller and a coupler, and the output end of the coupler is connected to the EtherCAT controller via an EtherCAT bus;

[0009] The signal acquisition system consists of a sound acquisition module, a vibration acquisition module, a temperature acquisition module, a pressure acquisition module, a vehicle communication module and an environment acquisition module.

[0010] Furthermore: the power supply system consists of a DC inverter module and a switching power supply, the input end of the DC inverter module is connected to the vehicle battery, the output end of the DC inverter module is connected to the input end of the switching power supply, and the output end of the switching power supply provides voltage to the main controller.

[0011] Furthermore: the EtherCAT controller is an integrated industrial computer with an operating frequency ≥ 2.0 GHz and a core number ≥ 2.

[0012] Further: the sound collection module is composed of a microphone and a microphone signal amplifier, and the microphone response frequency is ≥20kHz;

[0013] The vibration collection module is composed of 4 vibration sensors and a vibration signal amplifier, and the response frequency of the vibration sensor is ≥20kHz;

[0014] The temperature acquisition module is composed of 4 temperature sensors, and the temperature sensor measurement range is -40℃~500℃;

[0015] The pressure acquisition module consists of 4 pressure transmitters, and the pressure sensor measurement range is ≥25MPa;

[0016] The vehicle communication module is composed of two groups of CAN communication units, and the input end of the CAN communication unit is connected to the vehicle CAN interface through the CAN bus;

[0017] The environment acquisition module is composed of a temperature and humidity sensor, a GPS positioning sensor and a vehicle body deceleration sensor.

[0018] A vehicle brake noise measurement method based on EtherCAT bus, the method comprising the following steps:

[0019] Step 1: Set the brake pressure detection threshold PTh through the human-computer interaction system;

[0020] Step 2: Detect the vehicle's brake pressure Pb through the pressure sensor, and transmit the brake pressure to the EtherCAT controller through the coupler;

[0021] When Pb≥PTh, the EtherCAT controller collects and stores the sound pressure, vibration, temperature, pressure, ambient temperature and humidity, vehicle speed and vehicle deceleration signals of the braking process through the sound collection module, vibration collection module, temperature collection module, pressure collection module, environment collection module and vehicle communication module;

[0022] When Pb<PTh, the EtherCAT controller stops collecting data;

[0023] Step 3: After braking, the EtherCAT controller processes the sound pressure signal of the entire acquisition phase, obtains the spectrum of the sound pressure signal through fast Fourier transform, performs A-weighted filtering on the sound pressure spectrum, and calculates the peak value Lps and the corresponding frequency Fps of the spectrum of the sound pressure signal;

[0024] Step 4: The EtherCAT controller processes the four groups of vibration signals in the entire acquisition phase, obtains the spectrum of the vibration signal through fast Fourier transform, and calculates the peak values ​​Lpv1, Lpv2, Lpv3, Lpv4 and the corresponding frequencies Fpv1, Fpv2, Fpv3, Fpv4 of the spectrum of the four groups of vibration signals;

[0025] Step 5: The EtherCAT controller compares the peak frequency Fps of the sound pressure with the peak frequencies Fpv1, Fpv2, Fpv3, and Fpv4 of the four groups of vibration signals. If Fps is the same as any one or more of Fpv1, Fpv2, Fpv3, and Fpv4, it is determined that braking noise is generated during the braking process, and the time point of the braking is marked and stored; otherwise, it is determined that no noise is generated during the braking process.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) EtherCAT bus technology is used to achieve high-speed and efficient communication between subsystems, improving the integration and reliability of the system. The synchronization mechanism of the EtherCAT bus ensures that the data collected by each sensor is strictly synchronized in time, thereby improving measurement accuracy.

[0028] (2) Provides an intuitive and convenient human-computer interaction interface, allowing users to easily set test parameters and view measurement results. The system can be powered by the vehicle battery, meeting the requirements of on-board testing.

[0029] (3) Applicable to the measurement of brake noise of various types of vehicles, providing strong technical support for automobile testing. At the same time, the system and method can also be applied to vibration and noise testing in other industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a structural diagram of a vehicle brake noise measurement system based on EtherCAT bus of the present invention;

[0031] Figure 2 It is a structural diagram of the signal acquisition system of the present invention;

[0032] Figure 3The present invention is a flow chart of a vehicle brake noise measurement method based on EtherCAT bus.

[0033] In the figure: A, power supply system; B, main controller; C, signal acquisition system; D, human-computer interaction system; 1, DC inverter module; 2, switching power supply; 3, EtherCAT controller; 4, coupler; 5, sound acquisition module; 6, vibration acquisition module; 7, temperature acquisition module; 8, pressure acquisition module; 9, vehicle communication module; 10, environment acquisition module; 11, microphone; 12, sound transmission signal amplifier; 13, vibration sensor; 14, vibration signal amplifier; 15, temperature sensor; 16, pressure sensor; 17, CAN communication unit; 18, temperature and humidity sensor; 19, vehicle body deceleration sensor; 20, GPS positioning sensor. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should belong to the protection scope of the present invention.

[0035] See also Figure 1 and Figure 2 The present invention provides a vehicle brake noise measurement system based on EtherCAT bus, which includes a power supply system A, a main controller B, a signal acquisition system C and a human-computer interaction system D. The power supply system A provides power to the main controller B; the signal acquisition system C is connected to the main controller B through a signal transmission bus; and the human-computer interaction system D is connected to the main controller B through a data bus.

[0036] The power supply system A is composed of a DC inverter module 1 and a switching power supply 2. The input end of the DC inverter module 1 is connected to the vehicle battery and inputs a 12V DC voltage; the output end of the DC inverter module 1 is a 220V AC voltage, which is connected to the input end of the switching power supply 2. The switching power supply 2 then converts the AC into 24V DC, and the output end provides a stable DC voltage to the main controller B. At the same time, after the output end of the DC inverter module 1 is connected to the socket, it can power other electrical devices.

[0037] The main controller B is composed of an EtherCAT controller 3 and a coupler 4. The EtherCAT controller 3 is an integrated industrial computer with an operation frequency of not less than 2.0 GHz and a core number of not less than 2; the output end of the coupler 4 is connected to the EtherCAT controller 3 via an EtherCAT bus.

[0038] The signal acquisition system C is composed of a sound acquisition module 5 , a vibration acquisition module 6 , a temperature acquisition module 7 , a pressure acquisition module 8 , a vehicle communication module 9 and an environment acquisition module 10 .

[0039] like Figure 2 As shown, the sound collection module 5 is composed of a microphone 11 and a sound signal amplifier 12. The response frequency of the microphone 11 is not less than 20kHz. The microphone 11 is generally arranged next to the driver's ear; the vibration collection module 6 is composed of four vibration sensors 13 and a vibration signal amplifier 14. The response frequency of the vibration sensor 13 is not less than 20kHz. The vibration sensor 13 is generally in the form of a caliper and is arranged next to the brake; the temperature collection module 7 is composed of four temperature sensors 15. The measurement range of the temperature sensor 15 is: -40℃~500℃. The temperature sensor 15 is generally arranged on the brake disc or brake friction pad; the pressure The acquisition module 8 is composed of four pressure sensors 16. The measurement range of the pressure sensor 16 is not less than 25MPa. The pressure sensor 16 generally tests the pressure of the brake hydraulic pipe; the vehicle communication module 9 is composed of two groups of CAN communication units 17. The input end of the CAN communication unit 17 is connected to the vehicle CAN interface through the CAN bus; the environment acquisition module 10 is composed of a temperature and humidity sensor 18, a GPS positioning sensor 19 and a vehicle body deceleration sensor 20. The temperature and humidity sensor 18 and the GPS positioning sensor 19 are generally arranged on the top of the vehicle body, and the vehicle body deceleration sensor 20 is generally installed in the middle position of the vehicle center axis.

[0040] The human-computer interaction system D is composed of an integrated touch display screen and a software interface.

[0041] See also Figure 3 The present invention provides a vehicle brake noise measurement method based on EtherCAT bus, the method comprising the following steps:

[0042] Step 1: Setting the brake pressure detection threshold value PTh through the human-computer interaction system D;

[0043] Step 2: The pressure sensor 16 detects the braking pressure Pb of the vehicle, and transmits the braking pressure to the EtherCAT controller 3 through the coupler 4. When the EtherCAT controller 3 determines that the braking pressure reaches the detection threshold (Pb≥PTh), the EtherCAT controller 3 collects and stores the sound pressure, vibration, temperature, pressure, ambient temperature and humidity, vehicle speed and vehicle deceleration signals of the braking process through the sound collection module 5, the vibration collection module 6, the temperature collection module 7, the pressure collection module 8, the vehicle communication module 9, and the environment collection module 10; when the braking pressure Pb is lower than the detection threshold, the EtherCAT controller 3 stops collecting;

[0044] Step 3: After the braking is completed, the EtherCAT controller 3 processes the sound pressure signal of the entire acquisition phase, obtains the spectrum of the sound pressure signal through fast Fourier transform, performs A-weighted filtering on the sound pressure spectrum, and calculates the peak value Lps and the corresponding frequency Fps of the spectrum of the sound pressure signal;

[0045] Step 4: The EtherCAT controller 3 processes the four groups of vibration signals in the entire acquisition phase, obtains the frequency spectrum of the vibration signal through fast Fourier transform, and calculates the peak values ​​Lpv1, Lpv2, Lpv3, Lpv4 and the corresponding frequencies Fpv1, Fpv2, Fpv3, Fpv4 of the frequency spectrum of the four groups of vibration signals.

[0046] Step 5: EtherCAT controller 3 compares the peak frequency Fps of the sound pressure with the peak frequencies Fpv1, Fpv2, Fpv3, and Fpv4 of the four vibration signals. If Fps is the same as any one or more of Fpv1, Fpv2, Fpv3, and Fpv4, it is determined that braking noise is generated during the braking process, and the time point of the braking is marked and stored; otherwise, it is determined that no noise is generated during the braking process.

Claims

1. A vehicle brake noise measurement system based on EtherCAT bus, characterized in that: Including power supply system, main controller, signal acquisition system and human-computer interaction system; The power supply system provides power to the main controller; the signal acquisition system is connected to the main controller via a signal transmission bus; and the human-computer interaction system is connected to the main controller via a data bus. The main controller is composed of an EtherCAT controller and a coupler, and the output end of the coupler is connected to the EtherCAT controller via an EtherCAT bus; The signal acquisition system consists of a sound acquisition module, a vibration acquisition module, a temperature acquisition module, a pressure acquisition module, a vehicle communication module and an environment acquisition module.

2. The vehicle brake noise measurement system based on EtherCAT bus according to claim 1, characterized in that: The power supply system consists of a DC inverter module and a switching power supply. The input end of the DC inverter module is connected to the vehicle battery, the output end of the DC inverter module is connected to the input end of the switching power supply, and the output end of the switching power supply provides voltage to the main controller.

3. The vehicle brake noise measurement system based on EtherCAT bus according to claim 1 or 2, characterized in that: The EtherCAT controller is an integrated industrial computer with an operating frequency of ≥2.0 GHz and a core number of ≥2.

4. The vehicle brake noise measurement system based on EtherCAT bus according to claim 1, characterized in that: The sound collection module is composed of a microphone and a microphone signal amplifier, and the microphone response frequency is ≥20kHz; The vibration collection module is composed of 4 vibration sensors and a vibration signal amplifier, and the response frequency of the vibration sensor is ≥20kHz; The temperature acquisition module is composed of 4 temperature sensors, and the temperature sensor measurement range is -40℃~500℃; The pressure acquisition module consists of 4 pressure transmitters, and the pressure sensor measurement range is ≥25MPa; The vehicle communication module is composed of two groups of CAN communication units, and the input end of the CAN communication unit is connected to the vehicle CAN interface through the CAN bus; The environment acquisition module is composed of a temperature and humidity sensor, a GPS positioning sensor and a vehicle body deceleration sensor.

5. A method for measuring vehicle brake noise based on the EtherCAT bus-based vehicle brake noise measurement system according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: Step 1: Set the brake pressure detection threshold PTh through the human-computer interaction system; Step 2: Detect the vehicle's brake pressure Pb through the pressure sensor, and transmit the brake pressure to the EtherCAT controller through the coupler; When Pb≥PTh, the EtherCAT controller collects and stores the sound pressure, vibration, temperature, pressure, ambient temperature and humidity, vehicle speed and vehicle deceleration signals of the braking process through the sound collection module, vibration collection module, temperature collection module, pressure collection module, environment collection module and vehicle communication module; When Pb<PTh, the EtherCAT controller stops collecting data; Step 3: After braking, the EtherCAT controller processes the sound pressure signal of the entire acquisition phase, obtains the spectrum of the sound pressure signal through fast Fourier transform, performs A-weighted filtering on the sound pressure spectrum, and calculates the peak value Lps and the corresponding frequency Fps of the spectrum of the sound pressure signal; Step 4: The EtherCAT controller processes the four groups of vibration signals in the entire acquisition phase, obtains the spectrum of the vibration signal through fast Fourier transform, and calculates the peak values ​​Lpv1, Lpv2, Lpv3, Lpv4 and the corresponding frequencies Fpv1, Fpv2, Fpv3, Fpv4 of the spectrum of the four groups of vibration signals; Step 5: The EtherCAT controller compares the peak frequency Fps of the sound pressure with the peak frequencies Fpv1, Fpv2, Fpv3, and Fpv4 of the four groups of vibration signals. If Fps is the same as any one or more of Fpv1, Fpv2, Fpv3, and Fpv4, it is determined that braking noise is generated during the braking process, and the time point of the braking is marked and stored; otherwise, it is determined that no noise is generated during the braking process.

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