The application of the vehicle's lateral tilt angle sensor is an effective way to prevent the car from tipping off. It is an important measure to improve the safety of the car. Especially, it is necessary to improve the safety of the car.
With the development and application of electronic technology, car safety, comfort and intelligence are getting higher and higher. The application of the vehicle's lateral tilt angle sensor is an effective way Sensor to prevent the car from tipping off. It is an important measure to improve the safety of the car. Especially, it is necessary to improve the safety of the car. The
The essence of the car tipping is that the outward tipping moment is greater than the steady moment inward, and when the center of gravity is constant, the tipping moment is determined by the tipping force (outward lateral force). According to the knowledge of physics, the tipping force is generated by the sliding force F1 generated by the lateral (also known as lateral) slope of the road and the cohesive force of the centripetal force F2 at the time of turning. In order to reduce the tilt force, only the reduction v is feasible , And F2v2. According to Newton's third law of motion, when the car is subjected to centripetal force at the same time, the centrifugal force is the same as the centripetal force, and the car mass m is constant. When the centripetal force can not satisfy the increase of v2R, Steady torque, it will tipping over.
Therefore, the vehicle speed should be reduced, and then reduce the tilt torque, the angle sensor in the direction of the swing in the car on the side of the layout, according to the angle sensor angular displacement generated Suction Control Valve by the car by the sliding force, Of the size, when the angular displacement to a pre-set value, the car deceleration.
1 angle sensor using the principle of gravity manufacturing angle sensor. The swing part of the mass m, the center of gravity from the shaft of the distance L, when the car body tilt or do curve movement, can make part of the swing part of the deflection. Force force is the ideal state without any friction, the force F is the result of the interaction between the drag force F1 and the centripetal force F2, the force F is proportional to the tipping force, and the deflection angle is proportional to the tipping force. (F / G), has nothing to do with L, when the mass m is a certain, only with the F, and is proportional to the swing, the swing angle = tg-1 (F / G) In fact, due to the existence of friction at the shaft, etc., the longer L, the greater the swing torque, the higher the accuracy.
The angle sensor is usually used as a sampling element in the control system, and its performance plays an important role in the whole system. Potentiometer angle sensor has been widely used in a variety of control systems, but its drawback is the existence of contact slip wear and electrical noise; magnetoresistive angle sensor is the use of semiconductor technology to create a new type of pure resistive components, Non-contact, when the swing part of the deflection, through the magnetoresistance of the magnetic flux changes, the resistance of the resistance of several times more than the change, fundamentally eliminate Pressure Sensor the electrical noise, and to improve the accuracy. Various angle sensors have a damping function, so that a short delay in response to the measured angle is beneficial to the control system.
2 angle sensor circuit is a lateral tilt angle sensor of a practical circuit, mainly composed of a single power amplifier, its role is the angle sensor potentiometer W1 output of the linear changes in the analog power to deal with, zoom, Output digital and analog. K for the automatic re-type bit twist switch, as the circuit of the test switch, when moving up and down, respectively, should be diodes LED2, LED3, LED5 and LED1, LED4, LED6 light. Capacitor C1 is a high frequency bypass capacitor, C2 is a low frequency filter capacitor, and with the resistor R12 composed of discharge circuit, the formation of delay links, in the system is equivalent to the sensor damping effect increases. According to the foregoing description of the circuit of Fig. 2, there are two types of applications of the vehicle lateral tilt angle sensor. One by the circuit issued by the digital signal Uo2, driving the sound and light signal device to remind the driver to slow down; the second is issued by the digital signal Uo3 or analog signal Uo1 control actuator, the car automatically deceleration, the use of digital signal quantitative deceleration system , Slow down some speed change, the use of analog signal composition ratio reduction system, the effect of slowing down more smooth, there are two ways ABS Sensor to achieve deceleration, one is to reduce the engine throttle opening, the second is to increase the brake. As described below.
3. Decreasing the throttle opening of the quantitative deceleration system by the sensor circuit issued by the digital signal, the control components to reduce the engine throttle opening of the quantitative deceleration system. When the vehicle is running normally, the throttle lever is controlled by the accelerator pedal, and the moving core in the electromagnet moves synchronously with the throttle lever. When the vehicle is tilted sideways (the integrated value of the speed, turning radius and road gradient is the same) , The sensor circuit output Uo3 signal, the delay link YS (such as time relay, Uo3 disappeared, YS delay disconnect, if the damping and circuit delay enough, you can not set), switch amplification section KF (such as Relay), so that the electromagnet DCT work, moving the core quickly move to the end position, driven throttle rod, so that throttle opening suddenly reduced. In this system, the starting position of the moving core movement is not fixed, the stop position can be set in advance, the degree of deceleration obtained is different. Therefore, according to different models, a reasonable set to slow down the engine to achieve the speed, so that deceleration is not too sudden. Decreasing the throttle opening ratio Reducing system In order to avoid the above-mentioned system in the slowness of the mutation, should be used in the proportion Speed Sensor of deceleration system, in the proportional reduction system, the sensor circuit Uo1 output analog voltage signal, control the current amplification plate DF, according to the input signal Uo1 size, the output of different current values, so that the proportion of the electromagnet to produce different displacement, throttle opening reduction and Uo1 increase is proportional to the relationship between the deceleration of the final result is determined by the degree of tilt.
Deceleration system of the implementation of the displacement generated by the original car accelerator pedal generated by the direction of the displacement is the opposite, when the implementation of components to reduce the throttle opening, it is bound to lift the accelerator pedal, and to overcome the original car throttle Resistance, if the driver's foot on the pedal, the implementation of components to produce greater power to complete the action, while the transmission mechanism of mechanical parts strength, stiffness should also increase the requirements, making the deceleration system is not perfect.
In order to solve this problem, in the accelerator pedal and throttle rod between the addition of a transition spring, the accelerator pedal to the throttle lever force is small, the throttle pedal of the return spring is not directly on the throttle rod, so the original throttle Pedal directly driven throttle rod to increase the stiffness of a moderate transition spring (pull spring) to drive the throttle rod, normal work, does not affect the throttle pedal on the throttle rod control, when the slow down the implementation of components when the throttle opening to reduce And the transition spring is stretched, assuming that the driver's foot is not lifted and there will not be too much of the pedal up feeling or no feeling. If the position of the accelerator pedal remains the same, the tipping moment has not been applied after the deceleration phase has ended, the sensor circuit stops the signal output, the deceleration actuator stops working, the transition spring retracts, drives the throttle lever back to its original position, Accelerated, in the quantitative deceleration system Throttle Position Sensor to obtain the same degree of acceleration and deceleration in the proportion of deceleration system can be obtained with the corresponding slope of the ramp rate corresponding to the acceleration to achieve a smooth acceleration.
The brake actuators of the various vehicles are completed by the brake pedal. Therefore, the actuating actuators of the deceleration method for increasing the brake should act directly on the brake pedal, and the direction of the actuator Brake pedal down direction is consistent, the implementation of components and brake pedal connection can be used to achieve mechanical transmission structure.
Depending on the force required to depress the brake pedal, a permanent magnet type DC micro motor is used as the actuator. The speed of the motor output by the slowdown mechanism, driven screw rotation, so that the screw on the wire for the linear movement, and then by the wire on the rod by a thin wire rope to drive the brake pedal, the motor does not turn, the rod will limit Bit switch K1 to open, the brake pedal to work properly.
To increase the brake deceleration can be used in two kinds of control methods, namely, to increase the braking of the quantitative deceleration system and increase the proportion of the brake deceleration system, quantitative deceleration circuit, the motor directly connected to the power and rotation; in the proportional reduction circuit, Current amplifier board drive, the use of pulse width modulation method to make the current amplification board according to the size of the car tilt, at a certain time, to achieve a different maximum output current, the motor gradually accelerated to the corresponding maximum speed, the braking effect More smooth. The specific process is described below.
On the driving conditions of the car, the uphill, the engine throttle increased, the speed down, the slope is very steep, the engine speed will reach or even exceed the rated speed, speed also decreased; downhill, the engine idling speed is not Will be too low; horizontal road, sometimes speeding, the engine speed is high, sometimes glide, the engine idling. From the point of view of reducing the speed and preventing tipping, increasing the brake deceleration is a more direct way than reducing the engine throttle opening, but when the engine speed is high, it will cause the engine Pressure Switch to be stalled, only to reduce the engine Throttle opening sometimes can not achieve deceleration effect. Therefore, the application of the vehicle lateral tilt angle sensor should not only meet the deceleration requirements, but also can not cause the engine stall. Specifically reflected in the uphill slowdown.
In order to solve this practical problem, and then use an angle sensor and the vehicle longitudinal layout, when the slope up to the specified value (such as the maximum climbing), the op amp A2 output Uo4 output high, relay J was , The normally closed contact is disconnected and the power supply U1 of the brake reduction circuit is cut off so that it can not be operated because, in this case, as long as the engine is reduced in speed, a good deceleration effect is obtained and the engine Stalled. And in the remaining conditions (when the gradient is less than the specified value), the relay J does not pull, reduce the engine throttle speed deceleration system and increase the brake deceleration system at the same time to ensure that the car to obtain a reliable deceleration. The LED 2 is used as an instruction to increase the operating speed of the deceleration system.
Should be based on the car's center of gravity height, track, quality, speed, turning radius, road slope and bumpy vibration and other factors comprehensive decision to achieve a reasonable relationship with the fundamentally avoid the car in the lateral tipping accident occurred.