CN102756686A - Method and device for early alarming of side dumping of vehicle - Google Patents

Abstract

The invention discloses a method and device for early warning of vehicle rollover. A sensor is used to detect the lateral load transfer rate and lateral acceleration value of the vehicle during driving, and the sensor sends the detected data to a micro-processing unit. The micro-processing unit The lateral load transfer rate and lateral acceleration values are compared with their preset thresholds respectively, and when they exceed the preset thresholds, the processor will control the alarm device to give an alarm. Due to the adoption of the above-mentioned technical scheme, compared with the prior art, the present invention detects the leaf spring deformation stress value and the lateral acceleration value on both sides of the vehicle during driving, and compares the detection data through a processor to detect When the threshold is set, an alarm is issued; the lateral acceleration is used to correct the lateral load transfer rate to prevent false alarms and premature alarms caused by interference with the lateral load transfer rate judgment index caused by similar situations in the actual driving situation of the vehicle.

Description

Method and device for early warning vehicle rollover

technical field

The invention relates to a safety early warning method and device, in particular to a method and device for early warning vehicle rollover.

Background technique

With the continuous development of my country's automobile industry and the improvement of road traffic facilities, the speed of automobiles continues to increase, resulting in a large number of traffic accidents, casualties and huge economic losses. Therefore, the safety of automobiles has become more and more popular. Pay attention to. Some vehicles, such as tank trucks, medium and heavy trucks, and heavy-duty semi-trailers, are prone to rollover accidents when turning at high speeds and when the diameter of the curve is small due to their high center of mass position, large mass, and large volume. According to the United States Highway Traffic Safety Administration (NHTSA), the degree of harm caused by vehicle rollover accidents is second only to accidents caused by vehicle collisions, ranking second. Statistical analysis of traffic accidents in Europe and North America shows that vehicle rollovers account for 5% of traffic accidents resulting in personal injury and 20% of traffic accidents with fatalities. Vehicle rollover means that the vehicle rotates around the longitudinal axis during driving. Vehicle rollover refers to the dangerous sideways movement in which the vehicle rotates around the longitudinal axis at an angle of 90° or more during driving, so that the body contacts the ground. Vehicle rollover is generally divided into two types: one is tripping and rollover, that is, the vehicle slips sideways when driving, and it "trips" when it collides with obstacles on the road sideways; The rollover of the vehicle, that is, when the vehicle is running on the road, the vehicle's lateral acceleration exceeds the rollover threshold, and the vertical reaction force of the inner wheel is zero, causing rollover. There are many factors that affect vehicle rollover, which are usually divided into two categories: one is static factors related to vehicle design parameters, such as center of mass height, wheelbase, suspension and tire characteristics, etc.; the other is factors that vary with the driving of the vehicle. Such as the driver's steering mode, the shape and adhesion coefficient of the road surface, the type of vehicle load, whether there are obstacles on the road, etc. For example, when the tank of a tank car is filled with liquid, the quality of the liquid cargo is evenly distributed in the tank, and the rollover characteristics of the vehicle are basically the same as when transporting the same amount of solid cargo. However, when the tank is only partially loaded with liquid goods and turns to drive, due to the fluidity of the liquid, the liquid in the tank will shake, and under the action of gravity and inertial force, the position of the center of mass of the vehicle will also change, making the tank vehicle The rollover characteristics of the vehicle are affected, and its rollover threshold decreases, which easily leads to rollover accidents. At present, the Chinese Patent Publication No. CN2825373Y, the application titled "anti-rollover alarm device for dump truck", is characterized in that it uses two-way inclination angle switches to sense the lateral slope angle according to the actual situation of the dump truck during work, and the The angles are respectively closed conduction. Resistors are used for current limiting, and high-brightness light-emitting diodes and buzzers give audible and visual alarm prompts to the slope angle sensed by the tilt switch. The system has a single function and uses a mechanical switch. System popularization and application. The traditional roll measuring device simply measures the roll angle of the car or simply measures the lateral acceleration of the car. However, the experimental value of the vehicle's roll angle is very different from the actual value of the roll, and it is impossible to accurately judge whether the vehicle meets the roll condition. The invention adopts simultaneous measurement of two values of lateral acceleration and lateral load transfer rate as conditions for evaluating vehicle roll, so that the measurement result is more accurate and the reliability is stronger.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method and device for early warning of vehicle rollover, which has good accuracy, strong reliability and universal applicability, so as to overcome the deficiencies of the prior art.

The present invention is achieved in this way: the method for early warning vehicle rollover uses a sensor to detect the lateral load transfer rate and lateral acceleration value of the vehicle during driving, and the sensor sends the detected data to the micro-processing unit, and the micro-processing unit The lateral load transfer rate and lateral acceleration values are compared with their preset thresholds respectively, and when they exceed the preset thresholds, the processor will control the alarm device to give an alarm.

Said lateral load transfer rate is the ratio of the deformation stress values of the leaf springs on both sides of the vehicle.

The device for early warning of vehicle rollover includes a micro-processing unit, a power supply, the micro-processing unit is connected to the power supply, and the micro-processing unit is connected with a left leaf spring strain sensor, a right leaf spring strain sensor, a lateral acceleration sensor and an alarm device .

The alarm device includes an alarm, a safety light, a warning light, a warning light and a display.

The present invention is based on the experimental research of the experimental vehicle model, according to the deformation of the leaf springs on both sides of the vehicle and the characteristics of the lateral acceleration when the vehicle rolls critically, and uses the stress and strain sensor and the lateral acceleration sensor combined with the intelligent controller to monitor the running vehicle. Rollover detection, when the vehicle tends to roll over, it will give the driver an audible and visual alarm, so that the driver can take measures such as slowing down to avoid rollover accidents, or provide a rollover warning signal for future anti-rollover devices.

Specifically, the main judgment basis is to use the lateral load transfer to judge the vehicle rollover, that is, the rollover early warning algorithm. The rollover early warning algorithm estimates the lateral load transfer and lateral load by the ratio of the deformation stress values of the leaf springs on both sides of the vehicle. transfer rate.

The lateral load transfer rate LLTR (Lateral Load Transfer Rate) is defined as the ratio of the difference between the vertical load on the wheels on both sides of the vehicle to the sum of the vertical load, as shown in the following formula:

In the formula, F _li is the vertical load on the left wheel of the vehicle; F _ri is the vertical load on the right wheel of the vehicle; i and n are the position of the axle and the total number of axles, respectively. In the present invention, we take the last axle of the vehicle, that is, i=1, and take one axle, the calculation is simple and convenient, because when the vehicle rolls over, the last axle rolls over first and tends to roll over Y, therefore, for the last One axle is calculated.

In addition, the present invention also uses a lateral acceleration sensor to monitor the lateral acceleration of the vehicle, and supplements and corrects the rollover condition. Some special situations during the driving process of the vehicle, such as when the vehicle passes through large convex hulls, pits and inclined roads, will have a greater impact on the lateral load transfer rate of the vehicle. If only the lateral load transfer rate is used as rollover factor, the alarm system is prone to false alarms. The invention uses lateral load transfer rate and lateral acceleration as rollover factors, and the alarm device will alarm only when the measured values of the two factors exceed the preset threshold. Compared with other rollover warning systems, it gets rid of the shortcomings of low actual accuracy and poor reliability caused by a single rollover factor. Since the present invention calculates the lateral load transfer rate by measuring the deformation stress values of the leaf springs on both sides of the vehicle, Therefore, it is suitable for all vehicles with leaf springs as the elastic elements of the suspension system.

The micro-processing unit judges the driving status of the vehicle by acquiring the data monitored by the sensor, and the sensor transmits the real-time monitoring data to the micro-processing unit, and the micro-processing unit brings these data into the program preset in the micro-processing unit, and calculates the horizontal The load transfer rate and the lateral acceleration value are compared with the rollover threshold preset in the micro-processing unit program. If it is less than the rollover threshold, the alarm device will not alarm; if it is greater than the rollover threshold, it indicates that the vehicle has a rollover tendency. , the alarm device starts to alarm.

The working principle of the present invention is shown in Figure 2. When the vehicle is started, the micro-processing unit starts and starts to receive signals from the sensor output. When working, the micro-processing unit will detect the data transmitted by the leaf spring strain sensors on both sides in real time, and substitute the data into the existing program to calculate the lateral load transfer rate. At the same time, the micro-processing unit will detect the lateral acceleration value transmitted by the lateral acceleration sensor in real time, and the micro-processing unit will compare these two values with the preset threshold value. When these two values are greater than the preset rollover threshold value, the micro-processing unit will The processing unit will turn on the switch of the alarm device, and the alarm device will start to work with sound and light, that is, the alarm will sound an alarm buzzer and the alarm light will flash.

The right half of working principle Figure 2 is the auxiliary working part: the function of this part is to calculate the load ratio on both sides of the vehicle, and inform the driver through the alarm display. The system will alert the driver when the goods are placed unevenly or when the load ratio on both sides of the vehicle is too out of balance due to changes in the position of the goods on the way. The basis for judging the load ratio on both sides of the vehicle is to compare the ratio of the deformation stress values of the leaf springs on both sides of the vehicle. The prerequisite is that the vehicle is running smoothly, that is, the lateral acceleration is close to 0. As shown in schematic diagram 2, when the micro-processing unit detects that the deformation of the leaf spring has not returned to the initial value, it will detect the lateral acceleration sensor again to determine whether the lateral acceleration is close to 0. If so, the micro-processing unit will detect and compare the two The deformation stress value of the leaf spring on the side, and the calculated ratio is displayed on the alarm display, and then it is judged whether the ratio is overtraveled. If it is overtraveled, the pre-alarm light will flash to remind the driver.

The method of the present invention is accurate and reliable, the adopted components are mature in technology, small in size, high in work reliability, does not need to make major structural changes to existing models, is suitable for various types of old and new vehicles, and has a significant effect on improving the driving safety of vehicles. effect.

Due to the adoption of the above technical solution, compared with the prior art, the present invention detects the leaf spring deformation stress value and the lateral acceleration value on both sides of the vehicle during driving, and compares the detection data through a processor to detect An alarm is given when the threshold is set; the present invention estimates the lateral load transfer situation through the ratio of the strain force of the leaf springs on both sides, and uses the lateral acceleration to correct the lateral load transfer rate, comprehensively considering the lateral load transfer rate and lateral acceleration The rollover factor prevents false alarms and premature alarms caused by the interference of similar situations in the actual driving of the vehicle on the judgment index of the lateral load transfer rate, which greatly improves the actual accuracy of the alarm and the anti-interference ability. Strong. The method of the present invention is accurate and reliable, the adopted components are mature in technology, small in size, high in work reliability, does not need to make major structural changes to existing models, is suitable for various types of old and new vehicles, and has a significant effect on improving the driving safety of vehicles. effect.

Description of drawings

Accompanying drawing 1 is a structural representation of the present invention;

Accompanying drawing 2 is working principle figure of the present invention;

Accompanying drawing 3, accompanying drawing 4 are leaf spring strain sensor and microprocessing unit connection circuit diagram;

Accompanying drawing 5 is lateral acceleration sensor and microprocessing unit connection circuit diagram;

Accompanying drawing 6 is alarm circuit diagram;

Accompanying drawing 7 is safety etc., warning lamp and warning lamp circuit diagram;

Accompanying drawing 8 is the warning display circuit diagram.

Detailed ways

Embodiments of the present invention: a method for early warning of vehicle rollover, using sensors to detect the deformation stress value and lateral acceleration value of the leaf springs on both sides of the vehicle during driving, the sensor sends the detected data to the micro-processing unit, and the micro-processing Simply take the ratio of the deformation stress values of the leaf springs on both sides of the vehicle as the lateral load transfer rate of the vehicle, and compare the lateral load transfer rate and lateral acceleration values of the vehicle with their preset thresholds in the processing device, when they After exceeding the preset threshold, the processor will control the alarm device to give an alarm.

The structure of the early warning vehicle rollover device is shown in Figure 1. STC89C52 single-chip microcomputer is used as the micro-processing unit 1, which is connected to the power supply 2. The left leaf spring strain sensor 3 and the right leaf spring are connected to the micro-processing unit 1. A strain sensor 4, a lateral acceleration sensor 5 and an alarm device; the alarm device includes an alarm device 6, a safety light 7, an early warning light 8, a warning light 9 and a display 10; each component and the microprocessing unit 1 are connected by a communication signal line .

The power supply 2 adopts the vehicle power supply; the left leaf spring strain sensor 3 and the right leaf spring strain sensor 4 adopt the strain sensor model HBM K-LY4X-3/350; the lateral acceleration sensor 5 adopts the acceleration sensor model MMAmma7455; alarm The device 6 adopts a loudspeaker; the safety light 7, the warning light 8 and the warning light 9 adopt LED lights; the warning display 10 adopts a digital display tube or a vehicle-mounted liquid crystal display.

Claims (4)

1. A method for early warning vehicle rollover, characterized in that: utilize sensor to detect lateral load transfer rate and lateral acceleration value of vehicle in running process, sensor sends detected data to micro-processing unit, micro-processing unit The lateral load transfer rate and lateral acceleration values are compared with their preset thresholds respectively, and when they exceed the preset thresholds, the processor will control the alarm device to give an alarm. 2 . The method for early warning of vehicle rollover according to claim 1 , wherein the lateral load transfer rate is a ratio of the deformation stress values of the leaf springs on both sides of the vehicle. 3 . 3. A device for early warning of vehicle rollover, which includes a micro-processing unit (1), a power supply (2), and the micro-processing unit (1) is connected to the power supply (2), characterized in that: on the micro-processing unit (1) A left leaf spring strain sensor (3), a right leaf spring strain sensor (4), a lateral acceleration sensor (5) and an alarm device are connected. 4. The alarm device according to claim 3, characterized in that the alarm device comprises an alarm (6), a safety light (7), a warning light (8), a warning light (9) and a display (10).

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