CN101612927B - Dynamic detection method and early warning device for rollover-prevention for truck at curves - Google Patents

Abstract

The invention relates to a dynamic detection method and an early warning device for anti-rollover of a truck curve. , an inclination measuring device and an electronic control unit including a single-chip microcomputer; a center-of-mass height dynamic detection module and an anti-rollover early warning module are preset in the single-chip microcomputer; a rollover alarm range is preset in the anti-rollover early warning module; 2) collecting steering wheel angle signals , the vertical yaw rate signal of the truck, the roll angle signal of the truck compartment, the roll angle signal of the rear axle of the truck, and the longitudinal speed signal of the truck; 3) The center-of-mass height dynamic detection module calculates the lateral acceleration and center-of-mass height of the truck ; 4) the anti-rollover warning module calculates the rollover acceleration threshold according to the height of the center of mass; Alarm command; 6) After the anti-rollover warning module completes the alarm, return to step 2). The invention has high reliability and wide application range.

Description

Dynamic detection method and early warning device for anti-rollover of trucks on curves

technical field

The invention relates to a truck safety monitoring method and device, in particular to a truck curve anti-rollover dynamic detection method and an early warning device.

Background technique

When the truck is transporting goods, the height of its center of mass often changes due to the different types and weights of the goods loaded. If the height of the center of mass is high and the vehicle speed is fast, the truck is prone to rollover accidents when driving on a curve, causing heavy casualties and property losses. Therefore, domestic and foreign are actively researching on the operation safety and monitoring technology of trucks, such as the intelligent vehicle speed system, which realizes automatic control of vehicle speed according to road conditions and vehicle performance parameters, so that the vehicle can safely pass through curves; another example Based on vehicle-road coordination safety control technology, through vehicle-road communication information, on-board radar information, vehicle motion status information, etc., the vehicle's operating safety status can be judged in real time, and the vehicle can be safely operated by using on-board safety execution devices such as electronic auxiliary braking devices. run at speed. For these safety technologies, the vehicle's own performance parameters are the basis for establishing a correct safety control algorithm, and the vehicle's center-of-mass height is one of the most important parameters among these parameters. The identification of the vehicle's center-of-mass height is the ultimate The key to safety control, so the dynamic monitoring of the height of the center of mass of the vehicle is of great significance.

At present, the detection technology of the height of the center of mass of the truck is mainly to measure the height of the center of mass of the truck by using weighing instruments, tape measures, angle meters and other instruments. When the weight of the truck and the type of cargo change, the above process must be repeated to obtain its new centroid height. Therefore, for the current detection technology of the height of the center of mass of the truck, there are mainly the following problems: First, because the type and weight of the goods loaded on the truck often change, the existing detection technology is not targeted, when the loaded goods change It is difficult to know the actual height of the center of mass of the truck; second, it is difficult to guarantee the real-time accuracy of the height of the center of mass of the truck detected by the existing technology, which leads to the inaccuracy of the vehicle safety control algorithm based on the height of the center of mass of the truck, so it cannot effectively protect the truck. Operate safely on curves.

Contents of the invention

In view of the above-mentioned problems, the object of the present invention is to provide a dynamic detection method and early warning device for anti-rollover of truck curves with high reliability and wide application, which can provide early warning information in a timely, active and accurate manner when the truck is turning.

To achieve the above object, the present invention adopts the following technical solutions: a dynamic detection method for truck curve anti-rollover, which includes the following steps: 1) a dynamic detection and early warning device for truck curve anti-rollover is set, which includes a steering wheel angle measuring device , a yaw rate measuring device, an inclination measuring device and an electronic control unit including a single-chip microcomputer; a centroid height dynamic detection module and an anti-rollover early warning module are preset in the single-chip microcomputer; a side rollover warning module is preset in the anti-rollover early warning module 2) collect the steering wheel angle signal, the vertical yaw rate signal of the truck, the roll angle signal of the truck compartment, the roll angle signal of the rear axle of the truck, and the longitudinal speed signal of the truck; 3) the height of the center of mass The dynamic detection module calculates the lateral acceleration and the height of the center of mass of the truck; 4) the anti-rollover early warning module calculates the rollover acceleration threshold according to the height of the center of mass; 5) the anti-rollover early warning module compares the lateral acceleration and the rollover acceleration of the truck The difference between the threshold value and the preset rollover alarm range sends a corresponding alarm command; 6) After the anti-rollover warning module completes the alarm, return to step 2).

为货车侧向加速度，A_y为侧翻加速度阈值。The preset rollover alarm range in the step 1) is divided into three levels: if ${\hat{a}}_{\mathrm{the\; y}}<0.5A_{\mathrm{the\; y}},$ Alarm level G=0, the electronic control unit sends a non-alarm instruction to the alarm prompting device; if $0.5A_{\mathrm{the\; y}}\&le;{\hat{a}}_{\mathrm{the\; y}}<0.8A_{\mathrm{the\; y}},$ Alarm level G=1, the electronic control unit sends a primary alarm instruction to the alarm prompt device; if ${\hat{a}}_{\mathrm{the\; y}}\&Greater\; Equal;0.8A_{\mathrm{the\; y}},$ Alarm level G=2, the electronic control unit sends a high-level alarm command to the alarm prompt device; wherein,

is the lateral acceleration of the truck, and A _y is the rollover acceleration threshold.

The calculation formula of the lateral acceleration of the truck in the step 3) is as follows:

${\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; rs</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="L"\; filenames="H2009101585469E00021.png"\; state="\{\{state\}\}">L</figure-callout></span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; Cu</span>}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>$

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; rm</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&lambda;\&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; rs</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>$

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; a</span>}}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&Center\; Dot;</span>{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>$

为货车侧向加速度，ω_rs(k)为货车理论稳态横摆角速度信号，u(k)为货车车速信号，L为货车轴距，δ(k)为通过方向盘转角信号获取的货车前轮转角信号，C为货车的稳定性因数，

为校正稳态横摆角速度，λ为权系数，ω_rm(k)为横摆角速度；所述货车质心高度的计算式如下：In the formula, k represents the sampling time of the kth step,

is the lateral acceleration of the truck, ω _rs (k) is the theoretical steady-state yaw rate signal of the truck, u(k) is the speed signal of the truck, L is the wheelbase of the truck, and δ(k) is the front wheel Corner signal, C is the stability factor of the truck,

In order to correct the steady-state yaw rate, λ is the weight coefficient, and ω _rm (k) is the yaw rate; the formula for calculating the height of the center of mass of the truck is as follows:

H(k)=H(k-1)+Q(k)e(k)

为货车悬架的侧倾角刚度，为货车车厢的侧倾角度信号，为货车后轴的侧倾角度信号，H(k-1)为所述货车质心高度，h_a为货车车厢底部至路面的高度，m为货车质量，

为所述货车侧向加速度，g为重力加速度，Q(k)为增益矩阵，P(k-1)为对阵矩阵，ε为遗忘因子，P(k)为对阵矩阵。In the formula, k represents the sampling time of the kth step, H(k) is the height of the center of mass of the truck, e(k) is the estimation error at time k-1,

is the roll angle stiffness of the truck suspension, is the roll angle signal of the truck compartment, is the roll angle signal of the rear axle of the truck, H(k-1) is the height of the center of mass of the truck, h _a is the height from the bottom of the truck compartment to the road surface, m is the mass of the truck,

is the lateral acceleration of the truck, g is the gravitational acceleration, Q(k) is the gain matrix, P(k-1) is the pair matrix, ε is the forgetting factor, and P(k) is the pair matrix.

取6739Nm/deg。The Q(k) and P(k) are both 1×1 matrices, the initial value of P(k) is P(0)=1, the initial value of H(k) is H(0)=1.5m, and g is 9.8 m/s ² , ε is 0.99, h _a is 0.536m,

Take 6739Nm/deg.

The calculation formula of the rollover acceleration threshold in the step 4) is as follows:

In the formula, k represents the sampling time of the kth step, A _y is the rollover acceleration threshold, B is the wheelbase of the truck, and g is the acceleration of gravity.

The calculation formula of the rollover acceleration threshold in the step 4) is as follows:

In the formula, k represents the sampling time of the kth step, A _y is the rollover acceleration threshold, B is the wheelbase of the truck, and g is the acceleration of gravity.

An early warning device for realizing a dynamic detection method for truck anti-rollover curve, characterized in that it includes a steering wheel angle sensor installed on the steering column below the steering wheel of the truck; a yaw rate sensor installed at the bottom of the truck compartment The intersection of two central axes; an inclinometer, which is installed at the intersection of the longitudinal central axis at the bottom of the truck compartment and the projection of the rear axle on the compartment; another inclinometer, which is installed at the midpoint of the rear axle; An alarm prompting device, which is arranged on the center console of the driver's cab; an electronic control unit, which includes a single-chip microcomputer, and a centroid height dynamic detection module and an anti-rollover early warning module are preset in the single-chip microcomputer. The rollover alarm range is preset in the rollover warning module.

The electronic control unit also includes: a CAN bus transceiver circuit, the input end of which is connected to the original vehicle CAN network on the truck to receive the longitudinal vehicle speed signal of the truck in the vehicle CAN network; the output terminal of the CAN bus transceiver circuit is connected to The input end of the single-chip microcomputer transmits the longitudinal vehicle speed signal of the truck to the single-chip microcomputer; a serial port transceiver circuit, the input end of which is connected to the output ends of the two inclinometers, and the output end is connected to the input end of the single-chip microcomputer.

The alarm prompting device includes an integrated circuit and lights and sound prompting devices controlled by the integrated circuit, and the integrated circuit at least integrates an integrated circuit driven by four composite tubes.

Because the present invention adopts the above technical scheme, it has the following advantages: 1. The present invention can obtain the lateral direction of the freight car more accurately through the collection of various dynamic parameters of the freight car and the calculation of the center of mass height dynamic detection module preset in the single-chip microcomputer. The acceleration and the height of the center of mass provide a reliable basis for the calculation of the possibility of the truck rolling over. 2. The present invention can calculate the rollover acceleration threshold through the anti-rollover early warning module, and judge whether a rollover alarm needs to be performed according to the difference between it and the lateral acceleration. Therefore, the early warning result of the method of the present invention is scientific, accurate and effective. It effectively prevents the truck from rolling over and ensures the safety of the truck and the driver. 3. Since the present invention adopts the LH3-SX-4300A rotation angle sensor, it has high measurement accuracy, wide temperature range measurement, easy installation and high reliability. 4. Since the present invention adopts the LCG50-00100-100 sensor, it has high measurement accuracy, convenient installation and high reliability. 5. Since the LAM-TD-45D single-axis inclination sensor used in the present invention has a built-in temperature compensation and shock suppression module, the measurement accuracy is further improved. 6. Before calculating the height of the center of mass of the truck, the present invention further improves the accuracy of the measurement due to the use of a filter noise reduction circuit to filter the input basic parameter information of the truck dynamics. 7. The alarm prompting device of the present invention is composed of three-color light-emitting diodes and a buzzer controlled by an integrated circuit, which can drive the light-emitting diodes of corresponding colors according to the different alarm levels to remind the driver at a glance. The invention is suitable for various vehicles and has high reliability. When the vehicle is running on a curve, it can actively, timely and accurately send out early warning information to avoid the occurrence of traffic accidents.

Description of drawings

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

Fig. 2 is a schematic diagram of the installation position of the inclination measuring device of the present invention

Fig. 3 is the circuit schematic diagram of the electronic control unit of the present invention

Fig. 4 is the circuit schematic diagram of the alarm prompting device of the present invention

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

The inventive method comprises the following steps:

1) Set up a truck curve anti-rollover dynamic detection and early warning device, which includes a steering wheel angle measurement device 1, a yaw rate measurement device 2, an inclination measurement device 3 and an ECU (Electronic Control Unit, electronic control unit) 4 including a single-chip microcomputer U1 ; The single-chip microcomputer U1 is preset with a centroid height dynamic detection module and an anti-rollover early warning module; the anti-rollover early warning module is preset with a rollover alarm range.

2) Collect the steering wheel angle signal, the vertical yaw rate signal of the truck, the roll angle signal of the truck compartment, the roll angle signal of the rear axle of the truck, and the longitudinal speed signal of the truck.

3) The center-of-mass height dynamic detection module sequentially calculates the lateral acceleration and the center-of-mass height of the truck.

4) The anti-rollover warning module calculates the rollover acceleration threshold according to the height of the center of mass.

5) The anti-rollover warning module compares the calculated difference between the lateral acceleration of the truck and the rollover acceleration threshold with the preset rollover alarm range, and issues a corresponding alarm command.

6) After the anti-rollover warning module completes the alarm, return to step 2).

As shown in FIG. 1 , the present invention includes a steering wheel angle measuring device 1 , a yaw rate measuring device 2 , an inclination measuring device 3 , an ECU 4 and an alarm prompting device 5 .

Steering wheel angle measuring device 1 adopts a steering wheel angle sensor, which is fixedly installed on the steering column under the steering wheel of the truck, and is used to detect the steering wheel angle signal and send it to ECU4, and the signals sent to ECU4 are two analog voltage signals, one for It is used to judge the direction and number of turns of the steering wheel, and the other is used to judge the angle that the steering wheel has turned within the circle. In this embodiment, the steering wheel angle sensor is the LH3-SX-4300A type angle sensor of BI Company, the maximum input voltage is 16V, the measuring range is -900°～+900°, it can withstand the impact force of 10g, and it is suitable for the vehicle environment. The steering wheel angle measuring device 1 can also adopt various types of sensors, and its installation position can also be changed.

The yaw rate measuring device 2 adopts a yaw rate sensor, which is installed at the intersection of the two central axes at the bottom of the truck compartment, and is used to detect the vertical yaw rate signal of the truck and send it to ECU4, and the signal sent to ECU4 It is an analog voltage signal that changes between 0~5V. In this embodiment, the yaw rate sensor adopts the LCG50-00100-100 sensor of BEI Company, the rated input voltage is 5Vdc, and the range is ±100°/s, which meets the requirements for the use of trucks, but the type of yaw rate measurement device 2 It is not limited to this.

和货车后轴的侧倾角度

信号，输出信号

和

为数字信号，可以通过倾角仪31、32上的串口输送给ECU4。在本实施例中，两倾角仪31、32采用Lamshine公司的LAM-TD-45D型单轴倾角传感器，其内置有温度补偿及冲击抑制模块，适用于车载环境，但其中任一倾角仪也可以采用两个位移传感器来代替。As shown in Figure 2, the inclinometer 3 adopts two inclinometers 31, 32, wherein the inclinometer 31 is installed at the intersection of the longitudinal central axis of the bottom of the truck compartment and the projection of the rear axle on the compartment, and the inclinometer 32 is installed on the rear axle. at the midpoint of , respectively used to detect the roll angle of the truck compartment

and the roll angle of the rear axle of the truck

signal, output signal

and

It is a digital signal, which can be sent to ECU4 through the serial ports on the inclinometers 31 and 32 . In this embodiment, the two inclinometers 31 and 32 adopt the LAM-TD-45D single-axis inclination sensor of Lamshine Company, which has a built-in temperature compensation and impact suppression module, which is suitable for the vehicle environment, but any one of the inclinometers can also be Two displacement sensors are used instead.

As shown in FIG. 3 , ECU4 includes a single-chip microcomputer U1 and related peripheral circuits. The single-chip microcomputer U1 has three A/D conversion circuits, and a centroid height dynamic detection module and an anti-rollover warning module are preset inside. Among them, the three A/D conversion circuits convert the analog voltage signals output by the steering wheel angle measuring device 1 and the yaw rate measuring device 2 into digital signals, which are sent to the centroid height dynamic detection module, and the digital signals collected by the inclination measuring device 3 are directly Send it to the centroid height dynamic detection module. The centroid height dynamic detection module calculates the lateral acceleration and the centroid height of the truck according to the input information, and sends them to the anti-rollover early warning module, which calculates the truck rollover acceleration threshold. The anti-rollover warning module compares the calculated difference between the lateral acceleration of the truck and the rollover acceleration threshold with the preset rollover alarm range, and sends a corresponding alarm command to the alarm prompting device 5 . In this embodiment, the single-chip microcomputer U1 in the EUC4 is an eight-bit single-chip microcomputer with a model number of MC9S08DZ60 produced by Motorola, and other similar single-chip microcomputers can also be used, which is not limited here.

As shown in Figure 3, the peripheral circuit of ECU4 also includes a three-filter noise reduction circuit, its three input terminals are respectively connected to the two output terminals of the steering wheel angle measurement device 1 and the output terminal of the yaw rate measurement device 2, and the output terminals are respectively connected to the single-chip microcomputer U1 in the ECU4 The input terminals ADIN0, ADIN1 and ADIN2 of the three A/D conversion circuits. The input of the first filtering noise reduction circuit is the signal of the steering wheel rotation direction and the number of turns output by the steering wheel angle sensor 1. This circuit is composed of capacitors C11, C12 and resistor R1. After the capacitor C12 is connected in series with the resistor R1, the obtained series branch is the same as The capacitor C11 is connected in parallel; one end of the parallel circuit is grounded, and the other end is simultaneously connected to the input terminal ADIN0 of the first A/D conversion circuit and the anode of a diode D1, and the cathode of the diode D1 is connected to the power supply voltage VCC; the input of the second filtering noise reduction circuit What is more is that the steering wheel angle measuring device 1 outputs the signal of the angle that the steering wheel has turned in the circle. This circuit is composed of capacitors C13, C14 and resistor R2. After the capacitor C14 is connected in series with the resistor R2, the obtained series branch is connected in parallel with the capacitor C13; One end of the parallel circuit is grounded, and the other end is simultaneously connected to the input end ADIN1 of the second A/D conversion circuit and the anode of a diode D2, and the cathode of the diode D2 is connected to the power supply voltage VCC; the input of the third filtering and noise reduction circuit is the swing The signal output by the angular velocity measuring device 2, the circuit is composed of capacitors C15, C16 and resistor R3. After the capacitor C16 is connected in series with the resistor R3, the series branch obtained is connected in parallel with the capacitor C15; one end of the parallel circuit is grounded, and the other end is simultaneously connected to The input terminal ADIN2 of the third A/D conversion circuit is connected to the anode of a diode D3, and the cathode of the diode D3 is connected to the power supply voltage VCC. The filter noise reduction circuit is used to filter out the high-frequency noise in the analog signal to prevent signal aliasing in the subsequent A/D sampling process. In addition to the above-mentioned capacitive filter circuit, other capacitive filter circuits can also be used for the filter noise reduction circuit, which is not limited here. If the filter noise reduction circuit in this embodiment is used, the capacitors C11, C12, C13, C14, C15 and C16 are 1uF electrolytic capacitors, or other types of capacitors. When the electrolytic capacitors are used, the negative electrodes of the above capacitors are grounded . Resistors R1, R2 and R3 are 50kΩ. The diodes D1, D2 and D3 are used to ensure that the input voltages of the input terminals ADIN0, ADIN1 and ADIN2 of the three A/D conversion circuits in the single chip microcomputer U1 do not exceed the power supply voltage VCC.

As shown in Figure 3, the peripheral circuit of ECU4 also includes a CAN bus transceiver circuit, which uses PCA82C250 chip U2 as a driver. PCA82C250 is a dedicated CAN driver chip that provides differential transmission and differential reception capabilities for CAN bus and ECU5 respectively. And complete the conversion between CANH and CANL and CAN bus transmission and reception. The input end of the CAN bus transceiver circuit is connected to the original on-board CAN (Controller Area Network) network 6 of a truck, and is used to receive the longitudinal speed signal of the truck from the on-board CAN network 6, specifically: pins 7 and 6 of U2 are respectively connected to the vehicle CAN High side CANH and low side CANL for network 6. The output end of the CAN bus transceiver circuit is connected with the input end of the chip microcomputer U1, and is used to send the truck longitudinal speed signal book input by the vehicle-mounted CAN network 6 to the single chip microcomputer U1, specifically: the pins 1 and 4 of U2 are respectively connected to the pins of the single chip microcomputer U1. 29 feet and 30 feet are connected. Capacitors C21 and C22 are connected in parallel to form a filter voltage regulator circuit for U2. One end of the filter voltage regulator circuit is connected to pin 3 of U2, the other end is connected to pin 2 of U2, and pin 3 of U2 is also connected to the power supply voltage VCC. U2 Pin 2 is connected to ground.

As shown in Figure 3, ECU4 also includes a serial port transceiver circuit, which uses Max232 chip U3 as a serial port transceiver driver chip, which includes 2-way transmitters, 2-way receivers and a voltage generator circuit to provide TIA/EIA- 232-F level, in line with TIA/EIA-232-F standard. Each of the receivers converts TIA/EIA-232-F levels to 5V TTL/CMOS levels, and each transmitter converts TTL/CMOS levels to TIA/EIA-232-F levels. In this embodiment, U3 only uses one transmitter and one receiver. Pin 10 of U3 is connected to pin 15 of the single-chip microcomputer U1, pin 9 is connected to pin 16 of the single-chip microcomputer U1, pin 7 is connected to the sending line in the serial port line of the inclinometer 3 and 4, and pin 8 is connected to the serial port line of the inclinometer 3 and 4 connected to the receiving line in the Connect a capacitor C31 between pin 1 and pin 3 of U3, pin 1 is connected to the positive pole of C4; pin 4 and pin 5 are connected to a capacitor C32, pin 4 is connected to the positive pole of C32; pin 2 and pin 16 are connected to a capacitor C33, pin 2 is connected to the positive pole of C33, and pin 16 is connected to the power supply voltage VCC; pin 6 is connected to the positive pole of a capacitor C34, and the negative pole of C34 is grounded; pin 15 is connected to the negative pole of a capacitor C35, and the grounding wire of C35 is connected to the negative pole of C35. The positive pole is connected to the power supply voltage VCC; the other pins of U3 are floating. In this embodiment, U2 is a chip compatible with the RS232 standard launched by Texas Instruments (TI), and the capacitors C31, C32, C33, C34 and C35 are polarized capacitors of 1uF, but are not limited thereto.

和后轴的侧倾角度为

记由车载CAN网络6中接收的货车纵向车速信号为u(k)，其中k表示第k步采样时刻。Now record the steering wheel angle signal after filtering and noise reduction circuit and the AD sampling process by the single-chip microcomputer U1 as δ(k) and the yaw rate signal as ω _rm (k), record the output received by the inclinometer 31 and 32 by the serial port The roll angle of the truck compartment is

The roll angle of the rear axle is

Denote the truck longitudinal speed signal received by the vehicle CAN network 6 as u(k), where k represents the kth step sampling time.

The centroid height dynamic detection module in the single-chip microcomputer U1 calculates the centroid height of the truck according to the collected information, and the specific steps are as follows:

(1) Calculate the theoretical steady-state truck _yaw rate ω _rs (k): the center-of-mass height dynamic detection module uses the vehicle steady-state steering model to calculate the front wheel angle signal δ( k)=δ _sw (k) i _sw , the longitudinal speed signal u(k) of the truck received in the vehicle-mounted CAN network 6, its calculation expression is as follows:

${\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; rs</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="L"\; filenames="H2009101585469E00021.png"\; state="\{\{state\}\}">L</figure-callout></span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; Cu</span>}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>$

Among them, i _sw is the transmission ratio of the steering system of the truck, L is the wheelbase of the truck, and C is the stability factor of the truck. In this embodiment, i _sw =0.049, L=4.5m, C=0.0019s ² /m ² .

：质心高度动态检测模块读取横摆角速度实际测量值ω_rm(k)，考虑到横摆角速度的实际测量存在一定的误差，因此将实测横摆角速度值ω_rm(k)和理论稳态横摆角速度值ω_rs(k)进行加权平均，从而得到一个校正横摆角速度值，其计算式如下：(2) Calculation and correction of steady-state yaw rate

: The center-of-mass height dynamic detection module reads the actual measured value of yaw rate ω _rm (k). Considering that there is a certain error in the actual measurement of yaw rate, the measured yaw rate value ω _rm (k) and the theoretical steady-state lateral The weighted average of the yaw rate value ω _rs (k) is used to obtain a corrected yaw rate value, and its calculation formula is as follows:

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; rm</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&lambda;\&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; rs</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>$

Among them, λ is a weight coefficient, and the specific value depends on the accuracy of the yaw rate measuring device 2 and the specific installation method, and can also be calibrated by experiments. In this embodiment, λ=0.5 is taken.

质心高度动态检测模块根据校正横摆角速度

和当前纵向车速u(k)，其计算式如下：(3) Calculate the current lateral acceleration of the truck

The centroid height dynamic detection module corrects the yaw rate according to

and the current longitudinal vehicle speed u(k), the calculation formula is as follows:

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; a</span>}}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&CenterDot;</span>{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>$

也可以通过在货车上安装一侧向加速度传感器直接测取。In this example, the lateral acceleration

It can also be directly measured by installing a lateral acceleration sensor on the truck.

ε、h_a、m，及当前侧向加速度

和倾角

利用车辆稳态侧倾模型，建立车辆质心高度H(k)的回归最小二乘估计算法，其计算式如下：(4) Estimate the height of the truck's center of mass H(k): the dynamic detection module of the height of the truck's center of mass is based on the dynamic parameters of the truck

ε, h _a , m, and current lateral acceleration

and inclination

Using the steady-state roll model of the vehicle, a regression least squares estimation algorithm for the height of the vehicle's center of mass H(k) is established, and its calculation formula is as follows:

H(k)=H(k-1)+Q(k)e(k)

为货车悬架的侧倾角刚度，m为货车质量，g为重力加速度。本实施例中，Q(k)和P(k)均为1×1矩阵，即均为一个单值，P(k)的初始值取P(0)＝1，H(k)的初始值取H(0)＝1.5m，g取9.8m/s²，ε取0.99，h_a取0.536m，

取6739Nm/deg。Among them, e(k) is the estimation error at time k-1, Q(k) is the gain matrix at time k, P(k) is the pairing matrix at time k, H(k) is the estimated value of the centroid height, ε is the forgetting factor, h _a is the height from the bottom of the truck compartment to the road surface,

is the roll angle stiffness of the truck suspension, m is the mass of the truck, and g is the acceleration due to gravity. In this embodiment, both Q(k) and P(k) are 1×1 matrices, that is, they are all a single value, the initial value of P(k) is P(0)=1, and the initial value of H(k) H(0)=1.5m, g is 9.8m/s ² , ε is 0.99, h _a is 0.536m,

Take 6739Nm/deg.

After the current centroid height H(k) of the truck is obtained by using the above steps, the anti-rollover warning module in the single-chip microcomputer U1 calculates the lateral acceleration suffered by the truck when it starts to roll over, that is, the rollover acceleration threshold. The anti-rollover early warning module calculates the truck rollover acceleration threshold according to the quasi-static rollover calculation theory of the vehicle, and the calculation formula is:

Wherein, B is the wheelbase of the truck, and in this embodiment, B is 1.865m.

The lateral acceleration measured in step (3) when the truck drives through a curve or changes direction at a certain speed The closer to the rollover acceleration threshold A _y , the higher the risk factor of rollover. The anti-rollover warning module is preset with a rollover alarm range, which gives alarm prompts to the driver in different levels. The alarm level G and the division rules of the levels are as follows:

like ${\hat{a}}_{\mathrm{the\; y}}<0.5A_{\mathrm{the\; y}},$ Alarm level G=0, ECU4 sends a non-alarm instruction to the alarm prompting device 5;

like $0.5A_{\mathrm{the\; y}}\&le;{\hat{a}}_{\mathrm{the\; y}}<0.8A_{\mathrm{the\; y}},$ Alarm level G=1, ECU4 sends a primary alarm command to the alarm prompting device 5;

like ${\hat{a}}_{\mathrm{the\; y}}\&Greater\; Equal;{0.8A}_{\mathrm{the\; y}},$ When the alarm level G=2, the ECU 4 sends a high-level alarm command to the alarm prompting device 5 .

The division rules of the above alarm levels can not only send an alarm to the driver before the danger of the truck rolling over, remind the driver to slow down early, but also send different levels of alarm information to the driver according to the degree of danger of the truck’s operation. Driving characteristics of most drivers.

As shown in Table 1, after the alarm level is obtained according to the above alarm rules, the ECU 4 will drive the alarm prompt device 5 to provide early warning information to the driver in different ways according to the different alarm levels. Alarm prompting device 5 can realize functions such as light alarm and sound prompt alarm. Corresponding to the size of the alarm level G, the alarm mode of the alarm prompting device 5 also has three corresponding states.

Table 1

Alarm level G describe Lighting form Description of alarm sound 0 Safety green light on No alarm 1 Primary alarm yellow light flashing Beep with a frequency of 1Hz 2   Advanced Alarm flashing red light Beep with a frequency of 2Hz

As shown in FIG. 4 , the alarm prompting device 5 includes an integrated circuit U4 and a light and sound prompting device controlled by it. The integrated circuit U4 can directly drive the light and sound prompting device. The input terminals 1 pin (IN1), 2 pins (IN2), 3 pins (IN3) and 4 pins (IN4) of the integrated circuit U4 are respectively connected with the 4 output terminals of the single chip microcomputer U1, that is, 43 pins, 45 pins, 47 pins and 52 pins. The feet are connected. Among them, pin 1 inputs the center-of-mass height dynamic detection work indication signal, pin 2 inputs the primary alarm signal, pin 3 inputs the advanced alarm signal, pin 4 inputs the primary or advanced alarm signal, and pin 9 (K) of the integrated circuit U4 is connected to the power supply voltage VCC, 8-pin (GND) ground wire. The output terminal 16 (OUT1) corresponding to pin 1 is connected to pin 9 through a green light emitting diode (Light Emitting Diode) 1 and a resistor R4 in sequence, LED1 is a green light emitting diode; the output terminal 15 corresponding to pin 2 (OUT2) is connected to pin 9 through a red LED2 and a R5 in sequence, LED2 is a red light-emitting diode as a primary alarm light; the output terminal 14 (OUT3) corresponding to pin 3 is connected through a yellow LED3 and a resistor R6 in sequence It is connected with pin 9, and LED3 is a red light-emitting diode, which is used as a high-level alarm light; the output terminal 13 (OUT4) corresponding to pin 4 is connected with pin 9 through a buzzer LS1. In addition, a resistor R7 and an LED4 are connected in series between pin 9 and the ground wire, and the LED4 is a power indicator light, which is used to indicate whether the power supply of the system is normal. In this embodiment, the integrated circuit U4 is a compound tube driving ASIC with model MC1412 integrating 7 channels, and it can also be other composite tube driving ASICs integrating at least 4 channels. R4, R5, R6 and R7 are 1.2kΩ current-limiting resistors, which are used to prevent excessive current passing through each LED to protect the LED.

The alarm prompting device 5 works like this: when the ECU4 drives the alarm prompting device 5 to send out no alarm information, the pin 43 of the single-chip microcomputer U1 in the ECU4 sends a high-level signal to the pin 1 of the integrated circuit U4 in the alarm prompting device 5, and the integrated circuit Pin 1 of U4 is high level, pin 16 is connected to pin 8, the circuit where LED1 is located is closed, and LED1 is on at this time. When the ECU4 drives the alarm prompting device 5 to send primary alarm information, the 45 pins and 52 pins of the single-chip microcomputer U1 in the ECU5 send a square wave signal with a frequency of 1HZ to the 2 pins and the 4 pins of the integrated circuit U4 in the alarm prompting device 5, At this time, the levels of pins 2 and 4 of integrated circuit U4 alternately change at a frequency of 1Hz, and pins 1 and 3 are at low levels, and pins 13, 15 and 8 of integrated circuit U4 are alternately switched on and off at a frequency of 1Hz. , pins 14 and 16 are suspended in the air, and the corresponding LED2 and LS1 loops are switched on and off alternately at a frequency of 1Hz, then the primary alarm light LED2 flashes at a frequency of 1HZ, and the buzzer LS1 emits a buzzer at a frequency of 1HZ; when ECU4 drives the alarm prompt When the device 5 sends a high-level alarm message, that is, the 47 pins and 52 pins of the single-chip microcomputer U1 in the ECU4 send a square wave signal with a frequency of 2HZ to the 3 pins and 4 pins of the integrated circuit U4 in the alarm prompting device 5. At this time, the integrated circuit The level of pin 3 and pin 4 of U4 alternates between high and low at a frequency of 2 Hz, and pin 1 and pin 2 are at low level. At this time, pin 13, pin 14 and pin 8 of integrated circuit U4 are switched on and off alternately at a frequency of 2 Hz. Pins 15 and 16 are suspended in the air, and the corresponding circuits of LED3 and LS1 are switched on and off alternately at 2Hz, then the high-level alarm light LED3 flashes at a frequency of 2HZ, and the buzzer LS1 emits a beep at a frequency of 2HZ.

The structure, location, and connection of each component can be changed. On the basis of the technical solution of the present invention, the improvement and equivalent transformation of individual components should not be excluded from the protection scope of the present invention.

Claims (6)

1. A truck curve rollover prevention dynamic detection method comprises the following steps:

1) the method comprises the steps that a dynamic detection early warning device for preventing the rollover of a truck bend is arranged, and the dynamic detection early warning device comprises a steering wheel corner measuring device, a yaw angular velocity measuring device, an inclination angle measuring device and an electronic control unit comprising a single chip microcomputer; a mass center height dynamic detection module and a rollover prevention early warning module are preset in the single chip microcomputer; a rollover warning range is preset in the rollover prevention early warning module;

2) collecting steering wheel corner signals, transverse swing angular velocity signals of a truck in the vertical direction, side inclination angle signals of a truck carriage, side inclination angle signals of a truck rear shaft and longitudinal speed signals of the truck;

3) the mass center height dynamic detection module calculates the lateral acceleration and the mass center height of the truck, and the calculation formula of the lateral acceleration of the truck is as follows:

<math><mrow><msub><mi>&omega;</mi><mi>rs</mi></msub><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>=</mo><mfrac><mrow><mi>u</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>/</mo><mi>L</mi></mrow><mrow><mn>1</mn><mo>+</mo><mi>Cu</mi><msup><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mn>2</mn></msup></mrow></mfrac><mi>&delta;</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math>

<math><mrow><msub><mover><mi>&omega;</mi><mo>^</mo></mover><mi>r</mi></msub><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>=</mo><mrow><mo>(</mo><mn>1</mn><mo>-</mo><mi>&lambda;</mi><mo>)</mo></mrow><msub><mi>&omega;</mi><mi>rm</mi></msub><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>+</mo><msub><mi>&lambda;&omega;</mi><mi>rs</mi></msub><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math>

<math><mrow><msub><mover><mi>a</mi><mo>^</mo></mover><mi>y</mi></msub><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>=</mo><mi>u</mi><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow><mo>&CenterDot;</mo><msub><mover><mi>&omega;</mi><mo>^</mo></mover><mi>r</mi></msub><mrow><mo>(</mo><mi>k</mi><mo>)</mo></mrow></mrow></math>

where k denotes the sampling instant of the kth step,

for lateral acceleration, omega, of the truck_rs(k) Is goodsThe method comprises the steps of obtaining a truck theoretical steady state yaw angular velocity signal, wherein u (k) is a truck speed signal, L is a truck wheel base, delta (k) is a truck front wheel corner signal obtained through a steering wheel corner signal, C is a truck stability factor,

to correct for steady-state yaw-rate, λ is the weight coefficient, ω_rm(k) The yaw angular velocity;

the calculation formula of the height of the center of mass of the truck is as follows:

H(k)＝H(k-1)+Q(k)e(k)

wherein k represents the sampling time of the k step, H (k) is the height of the center of mass of the truck, e (k) is the estimation error of the k-1 time,

for the roll stiffness of the truck suspension,

is a side inclination angle signal of the boxcar,is the side inclination angle signal of the rear axle of the truck, H (k-1) is the height of the center of mass of the truck, H_aThe height from the bottom of the boxcar to the road surface, m is the mass of the truck,

taking the lateral acceleration of the truck, g is gravity acceleration, Q (k) is a gain matrix, P (k-1) is a matrix pair, epsilon is a forgetting factor, P (k) is a matrix pair, Q (k) and P (k) are both 1x1 matrixes, the initial value P (0) of P (k) is 1, the initial value H (0) of H (k) is 1.5m, and g is 9.8m/s²Epsilon is 0.99, h_aTaking the sample of 0.536m,

6739 Nm/deg.

4) The rollover prevention early warning module calculates a rollover acceleration threshold value according to the height of the mass center;

5) the rollover prevention early warning module compares the difference value of the lateral acceleration and the rollover acceleration threshold value of the truck with a preset rollover warning range and sends out a corresponding warning instruction;

6) and (5) after the rollover prevention early warning module finishes warning, returning to the step 2).

2. The method for dynamically detecting rollover prevention of a truck curve as recited in claim 1, wherein: the preset rollover alarm range in the step 1) is divided into three stages:

if it isThe alarm level G is 0, and the electronic control unit sends out a non-alarm instruction to the alarm prompting device;

if it isThe alarm level G is 1, and the electronic control unit sends a primary alarm instruction to the alarm prompting device;

if it is

The alarm grade G is 2, and the electronic control unit sends a high-grade alarm instruction to the alarm prompting device;

wherein,

for lateral acceleration of the truck, A_yIs the rollover acceleration threshold.

3. The method for dynamically detecting rollover prevention of a truck curve as claimed in claim 1 or 2, wherein: the rollover acceleration threshold calculation formula in the step 4) is as follows:

where k denotes the sampling time of the kth step, A_yThe rollover acceleration threshold value is B, the wheel track of the truck is B, and g is the gravity acceleration.

4. A truck curve rollover prevention dynamic detection early warning device for implementing the method according to claim 1, 2 or 3, wherein: the device comprises a steering wheel corner sensor, a steering wheel and a control unit, wherein the steering wheel corner sensor is arranged on a steering column below a truck steering wheel; the yaw angular velocity sensor is arranged at the intersection of two central axes at the bottom of the boxcar; the inclinometer is arranged at the intersection of the projection of the longitudinal central axis at the bottom of the boxcar and the rear shaft on the boxcar; another inclinometer mounted at the midpoint of the rear axle; the alarm prompting device is arranged on a center console of the cab; the electronic control unit comprises a single chip microcomputer, a mass center height dynamic detection module and a rollover prevention early warning module are pre-arranged in the single chip microcomputer, and a rollover warning range is pre-arranged in the rollover prevention early warning module.

5. The truck curve rollover prevention dynamic detection and early warning device as claimed in claim 4, wherein: the electronic control unit further includes:

the input end of the CAN bus transceiver circuit is connected with an original vehicle-mounted CAN network on the truck so as to receive a truck longitudinal speed signal in the vehicle-mounted CAN network; the output end of the CAN bus transceiving circuit is connected with the input end of the single chip microcomputer and transmits the longitudinal speed signal of the truck to the single chip microcomputer;

and the input end of the serial port transceiver circuit is connected with the output ends of the two inclinometers, and the output end of the serial port transceiver circuit is connected with the input end of the single chip microcomputer.

6. The truck curve rollover prevention dynamic detection and early warning device as claimed in claim 4 or 5, wherein: the alarm prompting device comprises an integrated circuit and a light and sound prompting device controlled by the integrated circuit, wherein the integrated circuit is at least integrated with an integrated circuit driven by a four-way composite tube.

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