CN110979336A

CN110979336A - Real-time monitoring system for running attitude of vehicle body

Info

Publication number: CN110979336A
Application number: CN201911347960.4A
Authority: CN
Inventors: 李冰; 吕景亮; 朱宝全; 裴玉龙
Original assignee: Northeast Forestry University
Current assignee: Northeast Forestry University
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2020-04-10

Abstract

The invention discloses a real-time monitoring system for the running attitude of a vehicle body, which comprises the following steps: acquiring the motion parameters of the running vehicle: the motion parameters comprise vehicle self speed information, vehicle self working condition information and driver behavior information; the data acquisition system synchronously acquires actual vehicle body posture information, vehicle self working condition information and driver behavior information by utilizing a multithreading technology, the data acquisition system uploads the information to the data processing unit, and the data processing unit performs fusion processing on the information to obtain the actual vehicle body posture; the data processing unit calculates a vehicle driving safety domain value, and if the vehicle driving safety domain value exceeds a preset safety domain threshold value, the data processing unit stores the safety domain value, sends out early warning information and gives an early warning to a driver to remind the driver that the vehicle is in a dangerous state; if the preset security domain threshold value is not exceeded, the data processing unit only stores the security domain value. The invention adopts the C + + multithreading technology to collect the data of each sensor in real time, and solves the problems of large error and poor monitoring effect caused by different data collection frequencies of each sensor.

Description

Real-time monitoring system for running attitude of vehicle body

Technical Field

The invention relates to the technical field of vehicle intelligent control, in particular to a real-time monitoring system for vehicle body operation attitude.

Background

Along with the higher requirements of people on the comfort and the safety of the automobile, the application of an intelligent control system based on an electronic technology to the automobile is increasingly common. In the running process of the vehicle, the posture of the vehicle body of the vehicle is timely adjusted according to the change of the speed and the road condition, so that the method has important significance for improving the comfort and the safety level of the vehicle, and the real-time perception of the posture condition of the vehicle body of the vehicle is an important link for realizing the adjusting technology.

At present, the real body attitude is generally detected by a gyroscope, but drift is easy to generate, the accumulated error of a system is difficult to eliminate, and the system needs to be corrected by other sensors; for example, patent 201220690699.5 discloses a security detection device for the posture of a car body, which detects the state of the car body through a three-axis MEMS acceleration sensor.

Disclosure of Invention

The invention aims to provide a real-time monitoring system for the running attitude of a vehicle body, which has small error and high monitoring precision and aims at overcoming the defects and shortcomings of the prior art.

In order to achieve the purpose, the invention provides the following scheme: the invention provides a real-time monitoring system for the running attitude of a vehicle body, which comprises the following steps:

acquiring the motion parameters of the running vehicle: the motion parameters comprise vehicle self-speed information, vehicle self-working condition information and driver behavior information, the vehicle self-working condition information comprises engine rotating speed information, vehicle speed information and throttle opening information, the vehicle self-speed information comprises vehicle body longitudinal, transverse and vertical speed information and acceleration information, and the driver behavior information comprises brake pedal control information and steering wheel corner information;

acquiring the actual body posture of the vehicle in running: the data acquisition system synchronously acquires the speed information of the vehicle, the working condition information of the vehicle and the behavior information of the driver by utilizing a multithreading technology, the data acquisition system uploads the information to a data processing unit, and the data processing unit performs fusion processing on the information to obtain the actual vehicle body posture;

judging a safety margin value during vehicle running: the data processing unit compares the acquired actual vehicle body posture with a preset vehicle body posture to obtain an actual safety domain value in the vehicle driving process, and if the actual vehicle body posture exceeds a preset safety domain threshold value, the data processing unit stores the safety domain value, sends out early warning information and gives an early warning to a driver to remind the driver that the vehicle is in a dangerous state; if the preset security domain threshold is not exceeded, the data processing unit only stores the actual security domain value.

Preferably, the multithreading technology comprises the following steps of utilizing an OBD decoding module to obtain information of the engine speed, the vehicle speed and the throttle opening degree in real time through a vehicle-mounted OBD interface; acquiring the longitudinal, transverse and vertical speed and acceleration information of the vehicle body by utilizing a nine-degree-of-freedom sensor; the control information of the brake pedal is obtained through the pedal force sensor, and the steering wheel angle information input by a driver is obtained through the steering wheel angle sensor.

Preferably, the steering wheel angle sensor is a pull-cord type displacement sensor.

Preferably, the OBD decoding module is composed of an automobile OBDCAN decoder and a dual-channel CAN bus analyzer.

Preferably, the brake pedal force sensor is a WTC280 brake pedal force manipulation force meter.

Preferably, the nine degree of freedom sensor is a nine axis accelerometer.

Preferably, a bluetooth module is arranged in the monitoring system, the OBD decoding module, the nine-degree-of-freedom sensor, the pedal force sensor and the steering wheel angle sensor are all connected with the corresponding bluetooth module, and each bluetooth module sends information to the data processing unit.

Compared with the prior art, the invention has the following beneficial effects:

the invention provides a brake pedal force sensor, a steering wheel corner sensor, a nine-axle vehicle body attitude sensor and a vehicle-mounted OBD interface decoding module (data stream reading) in a vehicle body operation attitude real-time monitoring system; based on the sensors, corresponding data communication and processing units are matched, and a system needs to synchronously acquire vehicle body attitude data, vehicle working condition data and driver behavior data, so that the problem of multi-sensor data synchronization is solved. Therefore, the system adopts the C + + multithreading technology to collect the data of each sensor in real time, and solves the problems of large error and poor monitoring effect caused by the influence of different data collection frequencies of each sensor.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a flow chart of the present invention vehicle body operation attitude real-time monitoring system;

FIG. 2 is a SBCAN-IIPro analysis module;

FIG. 3 is a USBCAN-IIPro wiring diagram.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1, the invention provides a real-time monitoring system for the running attitude of a vehicle body, comprising the following steps:

acquiring the actual body posture of the vehicle in running: the method comprises the following steps that a data acquisition system synchronously acquires vehicle speed information, vehicle working condition information and driver behavior information by utilizing a multithreading technology, the data acquisition system uploads the information to a data processing unit, and the data processing unit performs fusion processing on the information to obtain an actual vehicle body posture (wherein the fusion processing method adopts a data fusion algorithm in the prior art to judge the vehicle body posture, such as a method disclosed in a posture real-time display system of a large engineering machine with the application number of 201810039457.1);

judging a safety margin value during vehicle running: the data processing unit compares the acquired actual vehicle body posture with a preset vehicle body posture to obtain an actual safety domain value in the vehicle driving process (wherein the actual safety domain value in the vehicle driving process is calculated by utilizing a neural network algorithm in the prior art), and if the actual safety domain value exceeds the preset safety domain threshold value, the data processing unit stores the safety domain value, sends out early warning information, and gives an early warning to a driver to remind the driver that the vehicle is in a dangerous state; if the preset security domain threshold value is not exceeded, the data processing unit only stores the actual security domain value.

The multithreading technology comprises the following contents: the OBD decoding module is used for acquiring the information of the rotating speed, the speed and the opening degree of a throttle valve of the engine in real time through a vehicle-mounted OBD interface; acquiring the longitudinal, transverse and vertical speed and acceleration information of the vehicle body by utilizing a nine-degree-of-freedom sensor; the control information of the brake pedal is obtained through the pedal force sensor, and the steering wheel angle information input by a driver is obtained through the steering wheel angle sensor.

The steering wheel angle sensor is a pull rope type displacement sensor. The steering wheel angle sensor adopts a pull rope type displacement sensor to measure the rotation angle of the steering wheel (the specific parameters are shown in table 1), the pull rope type displacement sensor has the function of converting mechanical motion into an electric signal which can be measured, recorded or transmitted, the pull rope type displacement sensor is wound on a threaded hub by a stretchable stainless steel rope, the hub is connected with a precise rotary inductor, and the inductor belongs to an encoder; when the object to be measured generates displacement, the steel rope connected with the object to be measured is pulled, and the steel rope drives the sensor transmission mechanism and the sensing element to synchronously rotate; when the displacement moves reversely, the rotating device in the sensor automatically retracts the rope and keeps the tension of the rope unchanged during the extension and retraction of the rope, thereby outputting an electric signal which is in direct proportion to the movement amount of the rope. The output signal is measured to obtain the rotating direction and angle of the steering wheel, and the angular acceleration of the steering wheel can be calculated according to the relation between time and angle. A Bluetooth HC-05 data sending module is added on the basis of a processing circuit of the steering wheel angle sensor. The wire cable arrangement mode of the steering wheel angle sensor adopts automatic uniform wire arrangement, and the high independent linear precision and the long service life of the sensor are ensured.

TABLE 1 WLJ880 model steering wheel parameter tester specific parameters

Parameter(s)	Value range
		Measuring range	Steering wheel corner: +/-9999 degree
Power consumption	0.4W
		Error in indicating value	±1％FS
Division value	0.1°
		Data communication	Bluetooth
Error in indicating value	±1°
		Repeatability of	±1°

The OBD decoding module consists of an automobile OBDCAN decoder and a dual-channel CAN bus analyzer. The opening of the throttle valve, the speed and the acceleration data of the automobile can be branched out through an OBD interface of the automobile. The OBD decoding module consists of an automobile OBDCAN decoder and a dual-channel CAN bus analyzer. The OBDCAN decoder and the CAN bus analyzer adopt USB and OBD-II interfaces, have the characteristics of small volume and plug and play, are very suitable for collecting data on site and detecting the network state, and are also the best choice for portable system users. The USB-CAN card (adapter) CAN realize bidirectional data transmission of the bus, a special industrial-grade high-speed 32-bit CPU has a receiving and sending speed of 8000 frames/second (namely, when the baud rate of the CAN bus reaches the maximum 1M, the data frames sent by the bus at full time are not lost). And conforms to the ISO11898 standard, and supports CAN2.0A/B, standard frame/extended frame/data frame/remote frame. The data may be collected and shunted by ECANTOOLS, or CANTest.

The method comprises the steps of reading throttle opening data, car speed and the like in OBD data by adopting a Shenyang Guangdong science and technology company GCAN-600 embedded OBD decoding module and a USB-CAN converter USBCANII-pro, and calculating acceleration according to the relation between the throttle opening and time. The USBCAN-IIPro is a high-performance CAN-bus communication interface card integrating a 2-path CAN interface, the PC interface of the decoder conforms to the USB2.0 full-speed specification, is compatible with USB1.1 and USB3.0, integrates the 2-path CAN-bus interface, uses a plug-pull terminal wiring mode to support CAN2.0A and CAN2.0B frame formats, conforms to the ISO/DIS11898 specification, CAN realize the CAN-bus communication baud rate of between 5Kbps and 1Mbps, uses a USB bus power supply to supply power, or uses an external power supply (DC +5V, 130mA), the CAN-bus interface adopts electrical isolation, and an isolation module is insulated in voltage: DC3000V, highest received data traffic: 14000fps, and the accuracy of the time stamp of the message received by the CAN end CAN reach 1 us.

The USBCAN-IIPro interface card integrates 1 path of USB interface, one path of DC9-24V auxiliary power supply interface and 2 paths of quasi CAN-bus interfaces. The CAN-bus interface is led out by 16 Pin plug-in type wiring terminal and CAN be used for connecting 2 CAN-bus networks or equipment of the CAN-bus interface.

When the USB interface is installed, an automobile OBD interface is found, a 16-pin OBD-II interface of the USBCAN-OBD equipment is inserted into the automobile interface, and the USBCAN-OBD interface card is connected with the PC through Bluetooth and adopts a bus direct power supply mode. After the driver and the software are normally installed, the equipment is inserted into a USB interface of a PC, namely new USBCAN equipment can be found in a PC equipment manager, if no yellow exclamation mark or question mark exists, the equipment is normally driven, the USBCAN equipment is normally connected with the PC, and after a USBCAN-OBD interface card is electrified, an SYS lamp is lightened and is in red, the equipment is normally powered and is in an initialization state; when the computer recognizes the USBCAN equipment, the drive of the USBCAN equipment can be automatically loaded, and the indicator light can turn green after the loading is finished. After the USB interface is connected normally and the software is turned on, the SYS lamp flashes slowly, and when the USB bus has data to be transmitted, the USB signal indicator light SYS flashes quickly. After corresponding software and drivers are installed (such as ECANTOOLS), data acquisition can be carried out according to the following steps: 1. after the corresponding equipment type is selected, the CAN equipment which is inserted into the USB interface of the computer CAN appear in the equipment list by clicking 'open equipment'. 2. The operating mode is selected. The software provides 3 optional working modes: normal mode, listen-only mode, self-transmitting and self-receiving mode. The normal mode is suitable for software data transceiving; the listen-only mode is suitable for monitoring the bus without interfering the bus, but data CAN not be sent, and at the moment, the USBCAN equipment is not used as a CAN bus node and does not send response and clock signals; the self-sending and self-receiving mode is used for testing whether the CAN communication of the USBCAN equipment is normal. 3. The baud rate is selected. The setting needs to be carried out according to the baud rate of the actually accessed bus, and if the baud rate is not matched with the bus, normal communication cannot be carried out, and even the bus is interfered. The scan may also be performed using an auto-id baud rate function when the bus baud rate is unknown. The USBCAN-OBD device may use the car signal parsing function of the ECANTools software. The actual numerical value of the sensor in the automobile can be analyzed by using the device to access the OBD interface of the automobile. The vehicle speed, the rotating speed, the j throttle valve parameters and the like can be read through secondary development of the USBCAN-OBD. Fig. 2 and 3 show the selected OBDCAN bus parsing module in this embodiment. When the USBCAN-IIPro is connected into the CAN bus, the communication CAN be established only by connecting the CAN _ H with the CAN _ H and connecting the CAN _ L with the CAN _ L. The CAN-bus network adopts a linear topological structure, and 2 farthest terminals of a bus need to be provided with 120 omega terminal resistors; if the number of nodes is greater than 2, the intermediate node does not need to be equipped with a 120 Ω termination resistor. For a branched connection, its length should not exceed 3 m.

The brake pedal force sensor is a WTC280 brake pedal force operating force meter. The brake pedal force signal acquisition adopts a WTC280 brake pedal force control force meter of ZiBovor electronic technology Co., Ltd, and is used for measuring the brake pedal force values of various motor vehicles. The unit is newton (N). The measurement resolution is 0.1N, and the measurement precision is +/-2%. The measuring module mainly comprises a pedal force sensor and a data processing and transmitting module. The working principle is as follows: when the force of the brake pedal is measured, the force acting on the brake pedal is converted into a corresponding electric signal by using a pedal force sensor fixed on the brake pedal, pedal force parameters are obtained through conditioning, filtering and calculating of the signal, and then test data are sent to an upper computer through a Bluetooth wireless module to be processed.

TABLE 2 WTC280 brake pedal force manipulation force meter

Parameter(s)	Value range
		Measuring range	0～1000N
Power consumption	0.4W
		Error in indicating value	±2％
Capacity of battery	1500mah
		Resolution ratio	0.1N
Drift of	1％
		Repeatability of	2％

The nine-degree-of-freedom sensor is a nine-axis accelerometer. The sensor is characterized in that a Weiter BWT901CL nine-axis accelerometer (attitude measurement precision is 0.05 degree, range is acceleration +/-16 g, and angular velocity +/-2000 degrees/s) of Shenzhen Weiter Intelligent science and technology Limited is adopted, a Bluetooth connection function and a charging mechanism are installed on the basis of a JY901 sensor module, only a serial port is led out on the basis of JY901, the basic module of JY901 is not changed, other settings can be modified through an upper computer except for Baud rate fixing 115200, an AD converter is respectively adopted in three directions of JY901, angle change information is converted into digital quantity to be output, meanwhile, angular velocity values in 3 directions are integrated to obtain angle values, and wireless data transmission can be realized after the Bluetooth module and the charging module are accessed. The module integrates a high-precision gyroscope, an accelerometer and a geomagnetic field sensor, and can rapidly solve the current real-time motion attitude of the module by adopting a high-performance microprocessor and an advanced dynamic solution and Kalman dynamic filter algorithm. By adopting an advanced digital filtering technology, the measurement noise can be effectively reduced, and the measurement precision is improved. An attitude resolver is integrated in the module, and is matched with a dynamic Kalman filtering algorithm, so that the current attitude of the module can be accurately output in a dynamic environment, the power supply attitude measurement precision is 0.05 degree, and the stability is extremely high. And the module is internally provided with a voltage stabilizing circuit, the working voltage is 3.3V-5V, the pin level is compatible with a 3.3V/5V embedded system, and the connection is convenient. Up to 200Hz data output rate. The input content can be selected arbitrarily, and the output rate is adjustable from 0.1HZ to 200 HZ.

TABLE 3 JBWT901CL nine-axis sensor specific parameters

The accelerometer is arranged at the position of the virtual mass center of the automobile, and is used for reading the acceleration values of the X axis and the Y axis of the automobile and analyzing the transverse and longitudinal dynamic response characteristics of the automobile.

The monitoring system is provided with a Bluetooth module, the OBD decoding module, the nine-degree-of-freedom sensor, the pedal force sensor and the steering wheel corner sensor are all connected with the corresponding Bluetooth module, and all the Bluetooth modules send information to the data processing unit. The HC-05 Bluetooth module is additionally arranged at the data output end of the steering angle measuring module and the data output end of the brake pedal measuring module, so that the wireless transmission of the measured data is realized. After the steering wheel corner module, the vehicle body acceleration measuring module and the pedal force signal are processed by the signal conditioning circuit, the measured data are sent to the receiving module through the Bluetooth HC-05 module. Bluetooth HC-05 is a master-slave integrated Bluetooth serial port module, when the Bluetooth device is successfully connected with the Bluetooth device on the computer in a pairing manner, the communication protocol inside the Bluetooth is ignored, and the Bluetooth is directly used as a serial port. When the connection is established, two devices share one channel, namely the same serial port, one device sends data to the channel, and the other device can receive the data in the channel.

The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In summary, this summary should not be construed to limit the present invention.

Claims

1. The real-time monitoring system for the running posture of the car body is characterized by comprising the following steps of:

2. The system for monitoring the running posture of the car body in real time according to claim 1, wherein the multithreading technology comprises the following contents: the OBD decoding module is used for acquiring the information of the rotating speed, the speed and the opening degree of a throttle valve of the engine in real time through a vehicle-mounted OBD interface; acquiring the longitudinal, transverse and vertical speed and acceleration information of the vehicle body by utilizing a nine-degree-of-freedom sensor; the control information of the brake pedal is obtained through the pedal force sensor, and the steering wheel angle information input by a driver is obtained through the steering wheel angle sensor.

3. The system for monitoring the running posture of the vehicle body in real time as claimed in claim 2, wherein the steering wheel angle sensor is a pull rope type displacement sensor.

4. The real-time monitoring system for the running posture of the car body as claimed in claim 2, wherein said OBD decoding module is composed of an automobile OBD CAN decoder and a dual-channel CAN bus analyzer.

5. The system for monitoring the running posture of the vehicle body in real time as claimed in claim 2, wherein the brake pedal force sensor is a WTC280 brake pedal force manipulation force meter.

6. The system for real-time monitoring of the running attitude of the car body according to claim 2, wherein the nine-degree-of-freedom sensor is a nine-axis accelerometer.

7. A vehicle body operation posture real-time monitoring system according to any one of claims 2-6, characterized in that a Bluetooth module is arranged in the monitoring system, the OBD decoding module, the nine-degree-of-freedom sensor, the pedal force sensor and the steering wheel angle sensor are all connected with the corresponding Bluetooth module, and each Bluetooth module sends information to the data processing unit.