CN111845712B

CN111845712B - Control method of anti-rollover control system of tractor

Info

Publication number: CN111845712B
Application number: CN202010736931.3A
Authority: CN
Inventors: 高洁; 尹成强; 王守瑞; 袁冠豪; 姜超
Original assignee: Liaocheng University
Current assignee: Liaocheng University
Priority date: 2020-07-28
Filing date: 2020-07-28
Publication date: 2022-02-01
Anticipated expiration: 2040-07-28
Also published as: CN111845712A

Abstract

The invention provides a control method of a tractor rollover prevention control system, wherein the control system comprises a microprocessor, a pose detection module, a positioning module, an information sending module, a display module, a protection control module, a power supply module, a voltage detection module, a protection device, an alarm module, a data storage module, a serial port communication module and a protection device; the control method adopts a method of combining medium-mean filtering and Kalman filtering to obtain more accurate roll angle, judges rollover danger based on the roll angle and lateral acceleration, and grades the rollover danger to realize rollover prevention early warning and rollover prevention control; and when the tractor is at the highest rollover level, sending the position information of the tractor to a preset telephone number. The invention can judge, early warn and prevent the side-turning control of the side-turning state of the tractor, and can send distress information in the most dangerous state, thereby greatly reducing the personal injury and property loss caused by the side-turning of the tractor and improving the safe operation capability of the tractor.

Description

Control method of anti-rollover control system of tractor

Technical Field

The invention relates to a tractor control system, in particular to a control method of a tractor rollover prevention control system.

Background

Tractors are the most basic power machines in agriculture, and are representative agricultural implements for realizing agricultural mechanization. The wide application of the tractor actually reduces the working strength of agricultural operators, improves the agricultural production efficiency and yield and reduces the production cost. However, due to the rapid popularization of tractors, both extensive plains and steep mountains have become the field of work. From the safety perspective, because of the limitation of the existing tractor safety device, a driver often drives only by experience in a complex operation environment, so that the tractor working environment is changeable, the occurrence of tractor rollover accidents is also caused, and huge personal injury and economic loss are brought. According to statistics, 80% of the tractor rollover accidents are caused by the rollover of the tractor under the working condition, and 90% of drivers generally reflect that the inclination state of a vehicle body cannot be accurately sensed in the process of driving on a ramp, which is a direct factor for causing the ramp rollover.

At present, most of researches on the rollover prevention of tractors focus on the design of rollover prevention structures, and for example, the invention patent with the application number of 2018103326148 discloses a rollover protection device of a tractor, which utilizes inflatable telescopic beams to prevent the tractor from rolling continuously. The utility model discloses a grant utility model patent for 2018217644349 has authorized a bumper device that tractor mountain road dirt road turned on one's side, carries out the atress through the three shock attenuation arm of design and supports the both sides of tractor, prevents that the tractor from turning on one's side the back secondary that turns on one's side. The utility model with the authorization number of 2015205826817 authorizes the tractor to prevent the frame and the tractor with the frame that prevents rolling, prevents the frame through the design and avoids the tractor to the injury of driver when turning on one's side.

Furthermore, for example, the invention patent with application number 2019104095501 discloses an active anti-rollover control method and system for a wheeled tractor based on active steering control, which detects the posture of the tractor through a plurality of sensors, judges the rollover trend of the tractor by adopting an energy method, and calculates and controls the front wheel rotation angle of the tractor, thereby realizing the active anti-rollover control of the tractor.

In addition, from the viewpoint of vehicle stability, researchers have also conducted studies on the mechanical structure, active steering, and yaw control to avoid the tractor from rolling over due to instability.

According to the technical documents, and by looking up related design data and investigation reports, the tractor effectively prevents the rollover early warning system and the active rollover prevention technology under a general working environment, but the rollover accident of the tractor under an extreme working environment or an improper operation condition of a driver is difficult to avoid. Therefore, the passive rollover prevention technology, the injury reduction technology after rollover and emergency help are also very important, and the loss of personnel and property after the tractor rolls over can be greatly reduced. Therefore, the rollover prevention early warning technology, the active rollover prevention technology and the passive rollover prevention technology aiming at the operation process of the tractor have important application values.

Disclosure of Invention

The invention aims to provide a control method of a tractor rollover prevention control system, which realizes rollover early warning, rollover prevention control and emergency help information sending in the tractor operation process.

In order to solve the technical problems, the invention adopts the following technical means:

a control method of a tractor rollover prevention control system comprises a microprocessor, wherein the microprocessor is respectively connected with a pose detection module, a positioning module, an information sending module, a display module, a protection control module, a power supply module, a voltage detection module, a protection device, an alarm module, a data storage module and a serial port communication module, and the protection control module is also respectively connected with the voltage detection module, the power supply module and the protection device; the position and orientation detection module transmits monitoring information to the microprocessor, the longitude and latitude data of the position where the tractor is located, which are acquired by the positioning module, are transmitted to the microprocessor, the protection control module generates corresponding voltage according to the control of the microprocessor so as to control the electromagnetic directional valve to start the protection device, the power supply module is respectively connected with the microprocessor, the protection control module and the protection device, and the voltage detection module acquires voltage signals output by the protection control module and transmits the voltage signals to the microprocessor.

According to the technical scheme, the pose detection module is used for detecting the left and right inclination parameters of the tractor, the data are transmitted to the microprocessor, the microprocessor controls the display module, the protection control module and the alarm module to display and alarm relevant data, and the protection control module controls the protection device to act to perform rollover prevention control, so that rollover early warning and rollover prevention control are realized; in addition, the positioning module sends the monitored position information to the microprocessor, and the microprocessor sends the position information and the time information to a set client through the information sending module, so that the emergency help-seeking information is sent. In addition, the voltage detection module collects the voltage signal output by the protection control module, and the voltage signal is amplified and filtered and then is transmitted to the microprocessor. By detecting the output control voltage, the phenomenon that the protection device is out of control can be avoided, and the control safety is further improved.

The microprocessor employs a 32-bit ARM microcontroller STM32F 103.

The protection control module consists of a relay module, a D/A conversion chip, an operational amplifier and a peripheral circuit.

The power module comprises a chip for generating 24V voltage, a chip for generating 5V voltage, a chip for generating 4V voltage, a chip for generating 3.3V voltage, a chip for generating positive and negative 15V voltage, a chip for generating 10V voltage and a peripheral circuit.

The voltage detection module consists of an operational amplifier and a peripheral circuit.

The alarm module consists of two LED lamps, a buzzer and an auxiliary circuit.

The data storage module consists of a 16GB K9GAG08 chip and is used for recording some data information received or processed by the anti-rollover control system of the tractor in the driving process and providing data support for control strategy updating or fault diagnosis.

The serial port communication module is composed of a serial port communication chip MAX485 chip and a peripheral circuit thereof.

The positioning module is used for an NEO-6M positioning receiving module, and the microprocessor is connected with the positioning module in a serial port communication mode and used for receiving longitude and latitude and time information of the position where the tractor is located.

The information sending module adopts a module based on an SIM868 chip and is used for sending the current position and time information of the tractor to a preset telephone number in a short message mode.

The protection control module can generate corresponding voltage according to the control of the microprocessor and is used for controlling the electromagnetic directional valve to start the protection device.

The display module is used for displaying the on-line information and the prompt information of the positioning module and the information sending module.

The protection device is a left support device and a right support device which are controlled by a tractor hydraulic system and can be independently stretched and retracted.

The further preferred technical scheme is as follows:

the information sending module is used for sending the current position and time information of the tractor to a preset telephone number in a short message mode.

Through the arrangement, the mobile client can timely receive the related information, the control convenience of the system is further improved, and the system is favorable for timely rescuing serious accidents.

Through the arrangement, the relevant data can be observed conveniently in time, so that the system can be maintained conveniently.

According to the control method of the anti-rollover control system of the tractor, the pose detection module comprises a gyroscope and an acceleration speed which are respectively used for detecting the angular speeds of left and right inclinations of the tractor

And angle

At a sampling frequency of

Angular velocity within sample time

And angle

Sampling

Secondly; aiming at sampling values of angular velocity and angle, a microprocessor firstly adopts a medium-average filtering method to eliminate sampling and converting noise:

，

；

then eliminating the gyroscope by using the value of the accelerometer based on the Kalman filtering methodDrift error: establishing a state equation and an observation equation:

，

state variable of

Wherein

Is the drift deviation of the gyroscope,

is the measurement of the accelerometer(s),

，

process noise and observation noise; establishing a state and measurement updating equation:

，

，

，

；

through iterative calculationObtaining more accurate side inclination angle of tractor

。

By combining the working characteristics of the gyroscope and the accelerometer and adopting a data processing method combining the medium-average filtering and the Kalman filtering, drift errors and dynamic errors in the tractor pose detection process can be effectively eliminated, more accurate roll angles are provided for the tractor rollover prevention early warning and control, and the microprocessor is favorable for obtaining more accurate roll angles according to the obtained roll angles

And angular velocity

The size and direction of the tractor controls the tractor.

In the control method of the anti-rollover control system of the tractor, the microprocessor obtains the roll angle according to a mean value filtering method

And angular velocity

The size and orientation of (a) classify the rollover risk of the tractor into two grades:

(1) if the roll angle is satisfied

Then there is a secondary risk of rollover;

(2) if the roll angle is satisfied

Or lateral acceleration satisfies

The tractor has the first-level rollover danger;

the risk of the secondary rollover risk is greater than the primary rollover risk,

，

the value of (a) is determined by the parameters of the tractor.

According to the roll angle obtained by filtering, the rollover danger of the tractor is divided into two grades, and rollover early warning and passive rollover prevention technical schemes are adopted respectively, so that the rollover of the tractor caused by insufficient driving experience and extreme operating environment can be avoided to a great extent; when the tractor danger of turning on one's side was in the one-level, in order to reduce personnel's injury and the loss of property that the cause of turning on one's side, the system was equipped with GPRS communication module, sent the position information of tractor for preset's telephone number through this module, was favorable to emergency rescue more.

According to the control method of the anti-rollover control system of the tractor, the microprocessor starts corresponding early warning and anti-rollover measures according to the danger level, and starts the warning module if the rollover danger is a primary rollover danger, and starts the warning module, the protection control module and the information sending module if the rollover danger is a secondary rollover danger.

Drawings

Fig. 1 is a schematic block diagram of the present invention.

The invention provides a main flow chart of a control method for preventing a tractor from rolling over.

Description of reference numerals: 1-a microprocessor; 2-pose detection module; 3-a positioning module; 4-an information sending module; 5-a display module; 6-protecting the control module; 7-a power supply module; 8-a voltage detection module; 9-a protection device; 10-an alarm module; 11-a data storage module; 12-serial port communication module.

Detailed Description

The present invention will be further described with reference to the following examples.

Referring to fig. 1 and 2, the control system of the control method of the tractor rollover prevention control system of the invention comprises a microprocessor 1, a pose detection module 2, a positioning module 3, an information sending module 4, a display module 5, a protection control module 6, a power supply module 7, a voltage detection module 8, a protection device 9, an alarm module 10, a data storage module 11 and a serial port communication module 12; the microprocessor 1 is respectively connected with the pose detection module 2, the positioning module 3, the information sending module 4, the display module 5, the protection control module 6, the power supply module 7, the voltage detection module 8, the protection device 9, the alarm module 10, the data storage module 11 and the serial port communication module 12, and the protection control module 6is also respectively connected with the voltage detection module 8, the power supply module 7 and the protection device 9.

The microprocessor 1 adopts a 32-bit ARM microcontroller STM32F103, judges the rollover risk of the tractor through the processing data of the alignment posture detection module 2, and realizes corresponding early warning and control according to the risk level, thereby being the core of the rollover prevention control system of the tractor.

The protection control module 6 consists of a relay module, a D/A conversion chip DAC0832, an operational amplifier and a peripheral circuit and is used for generating positive and negative 8V voltage to control the reversing solenoid valve so as to control a left supporting device and a right supporting device which are connected with a hydraulic system.

The power module 7 is respectively connected with the microprocessor 1, the protection control module 6 and the protection device 9. The power module 7 is powered by a vehicle-mounted storage battery, 24V anti-surge voltage and 5V voltage are generated through an LT4356IS circuit and an LM7805 circuit respectively, positive and negative 15 voltages are generated through MD20-12D15 modules, and 10V reference voltage is generated through AD581 to supply power for the protection control module. The 5V voltage is generated by MP2303 to generate 4V voltage to supply power for the information sending module, and meanwhile, the 5V voltage is generated by RT9193-33 module to generate 3.3V voltage to supply power for the positioning module.

The voltage detection module 8 is connected with the protection control module 6, collects the voltage signal output by the protection control module 6, and is connected with the analog input port of the microprocessor 1 after amplification and filtering. The module is used for detecting the output control voltage, and the phenomenon that the protection device is out of control can be avoided.

The protection device 9 is composed of a left support device and a right support device which are controlled by a tractor hydraulic system and can independently stretch, and in the operation process of the tractor, the microprocessor 1 judges the rollover danger level according to the roll angle and starts the left or right support device.

The alarm module 6is electrically connected with the microprocessor 1 and consists of two LED lamps, a buzzer, an optical coupler and a relay. Book mould

The block is particularly suitable for reminding a driver to take corrective measures by controlling the optocoupler and the relay to start the LED flashing lamp and the buzzer on the corresponding side when the driver makes the tractor in a rollover dangerous level due to insufficient driving experience. The module is also activated when the tractor is in the rollover danger level two.

The data storage module 11 is composed of a 2GB × 8K 9GAG08 chip, and is used for recording some data information received or processed by the anti-rollover control system during the driving process of the tractor and providing data support for control strategy updating or fault diagnosis. The two chip select signals and the parallel data bits of K9GAG08 are electrically connected to the I/O port of the microprocessor 1.

The serial communication module 12 is connected with the microprocessor 1, and is composed of a MAX485 chip and a peripheral circuit, and the writing and reading of programs and data of the system and the PC can be realized through the serial communication module 12.

The pose detection module 2 comprises a gyroscope ADXRS614 and an accelerometer ADXL203 which are respectively used for detecting the lateral angular velocity of the tractor

And roll angle

. The gyroscope and the accelerometer are respectively connected with an analog input port of the microprocessor 1, and the microprocessor 1 can determine the direction and the size of the angular velocity and the angle according to the voltage value of the microprocessor. Set the sampling frequency of the gyroscope and accelerometer to be

Then the sampling period is

Separately collecting angular velocity and angle within a sampling time

Secondly; aiming at the angular speed and the angular value obtained by sampling, the microprocessor 1 firstly adopts a medium-mean filtering method to eliminate sampling and converting noise

，

Then, based on a Kalman filtering method, the drift error of the gyroscope is eliminated by using the value of the accelerometer: establishing a state equation and an observation equation

，

State variable of

Wherein

Is the drift deviation of the gyroscope,

is the measurement of the accelerometer(s),

，

in order to be able to detect process noise and observation noise,

，

，

。

establishing a state and measurement updating equation:

，

，

，

，

. Obtaining more accurate tractor side inclination angle through iterative calculation

。

The microprocessor 1 obtains the roll angle according to the filtering

And angular velocity

The magnitude and direction of (A) classify the rollover risk of the tractor into two categories if it is heeledCorner satisfies

Then there is a secondary risk of rollover; if the roll angle is satisfied

Or lateral acceleration satisfies

The tractor has the first-level rollover danger. The secondary risk is greater than the primary risk,

，

the value of (a) is determined by the specific parameters of the tractor.

The microprocessor 1 starts a corresponding early warning and rollover prevention device according to the danger level. If the rollover danger is first level, only the alarm module 10 is started to remind the driver of correcting in time; if the rollover danger is in the second level, the alarm module 10, the protection control module 6, the protection device 9 and the information sending module 4 are simultaneously started, the tractor is prevented from rollover through the control protection device, and the real-time position information of the tractor is sent to a preset number so as to facilitate emergency rescue.

The positioning module 3 is selected for the NEO-6M positioning receiving module, and the acquired longitude and latitude data of the position where the tractor is located is sent to the microprocessor 1 through a serial port. The receiving and sending interfaces and the output I/O interface of the serial communication interface UART1 of the microprocessor 1 are connected with the positioning module 3, and if the positioning module 3 works abnormally, the microprocessor can control the output of the switching power supply to reset the positioning module through the I/O interface.

The information transmission module 4 is a module based on a SIM868 chip, and is connected to a transmission/reception interface and an output I/O of the serial communication port UART2 of the microprocessor 1. When the rollover danger of the tractor is in the second level, the microprocessor 1 sends the current position and time data of the tractor, which are received by the positioning module 3, to the information sending module 4 through serial port communication, and the information sending module 4 sends the data to a preset telephone number in a short message form.

The protection control module 6 can generate corresponding voltage according to the control of the microprocessor 1, and is used for controlling the electromagnetic directional valve to start the protection device 9.

The display module 5 is used for displaying the connection information and the prompt information of the positioning module 3 and the information sending module 4.

FIG. 2 is a main flow chart of a method for controlling the tractor to prevent the side turning over, which specifically comprises the following steps:

s1, initializing the system after powering on, including setting each port, A/D conversion, clock, serial port, interrupt function and pin;

s2, after the system initialization is finished, firstly resetting the protection device, the protection control and the alarm to ensure that the anti-rollover system is in a normal state;

s3, after the positioning module is powered on and initialized, continuously searching for available satellites, after the satellite is successfully acquired, interrupting through a serial port UART1, calling a positioning receiving function and storing data;

s4, calling a data analysis function to analyze the received data, searching useful data through a variable search statement identification head, and calling a data effective function to judge whether the data is effective positioning data; if the received data is not valid location information, return to S3;

s5, if the received data is judged to be effective positioning data, calling a display module and displaying the GPS connection success information on an LCD screen;

s6, converting the latitude in the received positioning data into degree format, and storing the time, longitude and latitude data, the start bit and the check bit in a character string form for use by an information sending module;

s7, after the GPRS module is electrified, initializing parameters including serial port baud rate and dialing parameters, and because the system only adopts the short message function of GPRS, the dialing connection is not required to be established;

s8, if the GPRS connection is unsuccessful, jumping to S7 to continue the connection test;

s9, if the GPRS connection is successful, calling a display module to display the GPRS connection success information on the LCD screen; meanwhile, the microprocessor receives data of the gyroscope and the accelerometer through reading the AD interface;

s10, filtering the angular speed and the angle by the microprocessor by adopting a medium-average filtering method, and then obtaining the roll angle of the tractor by utilizing a Kalman filtering method;

s11, the microprocessor determines a rollover threshold value according to the parameters of the tractor, determines two rollover risk levels, and judges the rollover risk level of the tractor according to the roll angle and the size and direction of the angular velocity obtained by filtering;

s12 if the tractor inclines

The rollover danger level of the tractor is in the second level;

s13, when the tractor has the danger of secondary side turning, the microprocessor opens the relay for protection control, the protection control and the protection device, and opens the alarm module;

s14, setting TEXT information mode, center number and user number, and sending character string containing start position, time, longitude and latitude, check position in short message form through GPRS module;

s15, if the short message fails to be sent, the position information is continuously sent, if the short message is successfully sent, the operation is carried out by skipping to S9;

s-12, if the side inclination angle of the tractor meets the requirement

Or lateral angular velocity satisfies

The rollover danger level of the tractor is one level;

s-13, when the tractor has a primary rollover danger, the microprocessor starts the alarm module and jumps to S9 to execute circularly, and if the tractor does not have the primary rollover danger, the microprocessor also jumps to S9 to execute circularly.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, which is defined in the appended claims.

Claims

1. A control method of a tractor rollover prevention control system is characterized by comprising the following steps:

the control system comprises a microprocessor, the microprocessor is respectively connected with a pose detection module, a positioning module, an information sending module, a display module, a protection control module, a power supply module, a voltage detection module, a protection device, an alarm module, a data storage module and a serial port communication module, and the protection control module is also respectively connected with the voltage detection module, the power supply module and the protection device; the position and orientation detection module transmits monitoring information to the microprocessor, the longitude and latitude data of the position of the tractor, which are acquired by the positioning module, are transmitted to the microprocessor, the protection control module generates corresponding voltage according to the control of the microprocessor so as to control the electromagnetic directional valve to start the protection device, the power supply module is respectively connected with the microprocessor, the protection control module and the protection device, and the voltage detection module acquires a voltage signal output by the protection control module and transmits the voltage signal to the microprocessor;

the information sending module is used for sending the current position and time information of the tractor to a preset telephone number in a short message form;

the display module is used for displaying the on-line information and the prompt information of the positioning module and the information sending module;

the pose detection module comprises a gyroscope and an acceleration speed which are respectively used for detecting the angular speed of the left and right inclination of the tractor

And angle

At a sampling frequency of

Angular velocity within sample time

And angle

Sampling

，

；

then, based on a Kalman filtering method, the drift error of the gyroscope is eliminated by using the value of the accelerometer: establishing a state equation and an observation equation: