CN203381621U - Intelligent vehicle speed control system - Google Patents

Abstract

The utility model discloses an intelligent vehicle speed control system, which comprises an ultrasonic sensor and an infrared sensor, and the ultrasonic sensor and the infrared sensor are respectively connected with an analog input circuit, the analog input circuit is connected with a single-chip microcomputer, and the single-chip microcomputer is respectively connected with a driving circuit and a voltage stabilizing circuit , a display module and an alarm module; the drive circuit is connected to a motor. The system can realize the intelligent control of the speed of the vehicle when the driver has no time to react. Ultrasonic sensors are used for measurement, the single-chip microcomputer calculates the data and outputs PWM waves, and controls the speed of the motor through the motor drive circuit to realize a series of operations such as deceleration and braking. The system has high measurement accuracy, fast data processing speed, and good anti-interference performance, which ensures that the system can control the speed of various vehicles in different environments and different vehicles that use electric motors as power sources.

Description

A vehicle speed intelligent control system

technical field

The utility model relates to an intelligent vehicle speed control system, in particular to an intelligent vehicle speed control system based on Freescale MC9s12xs128 series single-chip microcomputer control.

Background technique

An electric motor is a high-efficiency electrical component that converts electrical energy into kinetic energy. Installing the motor on the car as a power drive component has many advantages: the use of electronic devices is convenient for control, high energy conversion efficiency, easy disassembly and replacement, high reliability, good safety, environmental protection, pollution-free, strong anti-seismic performance, long service life, etc. . Therefore, the transition from thermal to electrical technologies in the combustion of fuels will significantly reduce energy consumption in automotive applications. At present, automobiles have penetrated into the family, and the safe driving of automobiles is related to the happiness of every family and the stability of the country; however, collisions and rear-end collisions occur from time to time, and there are frequent tragic incidents of accidental stepping on the accelerator instead of the brake in a desperate situation Appear. In order to improve the power, economy, environmental protection, safety, maneuverability, and comfort of automobiles, various safety devices have emerged as the times require, making the driving operation of the automobile easier and more reliable, and the ride more comfortable and safe. At present, the safety measures on automobiles include seat belts, safety airbags, etc. These devices have the following problems: safety airbags are not only costly, but also take up a lot of space. Economic losses.

Therefore, with the development of electronic technology, especially single-chip microcomputers, cars can be made more intelligent.

Utility model content

The purpose of the utility model is to provide an intelligent control system for vehicle speed, which can solve technical problems, realize intelligent control of vehicle speed within a certain distance range, and has good reliability.

The purpose of this utility model is achieved through the following technical solutions.

An intelligent vehicle speed control system, comprising an ultrasonic sensor and an infrared sensor, the ultrasonic sensor and the infrared sensor are respectively connected to an analog input circuit, the analog input circuit is connected to a single-chip microcomputer, and the single-chip microcomputer is respectively connected to a driving circuit, a voltage stabilizing circuit, a display module and an alarm module; the drive circuit is connected to the motor.

Further, the single-chip microcomputer is respectively connected with the ultrasonic sensor and the infrared sensor.

Further, the single-chip microcomputer adopts mc9s12sx128 single-chip microcomputer.

Further, the voltage stabilizing circuit includes a socket, the socket is connected to a switch, the switch pin 3 is respectively connected to the pin 1 of the chip LM2940 and LM7805, the switch pin 4 is connected to a light-emitting diode D1 and a resistance RD to ground; the LM7805 pin 2 is grounded , LM7805 pin 3 is connected to the output load, LM7805 pin 1 is grounded through capacitor C4, LM7805 pin 3 is grounded through electrolytic capacitor C44; LM2940 pin 2 is grounded, LM2940 pin 3 is connected to the output load, LM2940 pin 1 and pin 3 Connect to ground through capacitor C2 and electrolytic capacitor C22 respectively.

Further, the drive circuit includes two BTS7960B chips connected in parallel, wherein PWM1 and PWM2 of each BTS7960B chip are respectively connected to a single-chip microcomputer; IN1 and IN2 of the two BTS7960B chips are respectively connected to a power supply.

Further, the PWM1, PWM2 and IN1, IN2 of each BTS7960B chip are respectively connected to the pins of the BTS7970 control chip through resistors.

Further, the BTS7970 control chip is grounded after passing through a resistor.

Further, the OUT1 and OUT2 of the BTS7970 control chip are respectively connected to the two ends of the motor; the pin 7 is connected to the power supply voltage VCC7 and grounded after being connected to a capacitor.

The beneficial effects of the utility model are:

1) For the selection of each component, ultrasonic sensor devices are used for data collection, and infrared sensor devices are used for speed feedback control, which greatly reduces power consumption. The selection of some resistors and capacitors is also selected to reduce power consumption.

2) Two pieces of motor driver chips BTS7970 are used to form the H full-bridge driver circuit. The driver IC integrated inside the BTS7970 makes the interface with the microcontroller very easy, and has logic level input, current detection and diagnosis, slope correction, dead Zone time generation and over-temperature, over-voltage, under-voltage, over-current and short-circuit protection functions. Two BTS7970 can be connected to form an H full bridge. The typical value of the on-state resistance of BTS7970 is 16mΩ, and the driving current can reach 43A. The acceleration and deceleration of the motor can be realized by adjusting the duty cycle of the PWM wave unidirectionally. However, in more complicated cases, the motor needs reverse braking with reverse voltage to achieve deceleration.

3) The special device includes ultrasonic sensor acquisition circuit, voltage stabilization circuit, core control chip, liquid crystal display circuit, motor drive circuit, etc. The core controller processes the collected signal through software, and outputs control PWM wave to control the motor speed. The voltage stabilizing circuit is firstly stabilized by the LM2940 and LM7805 chips, so that the voltage changes to 5V, which is supplied to other circuit modules to make each module work normally. The single-chip microcomputer first controls the ultrasonic signal to send out, and then processes the received data to calculate the speed, distance and other information, and then outputs the PWM wave of the corresponding speed, controls the motor drive circuit, and controls the motor speed. The infrared sensor will collect the returned vehicle speed. The signal is transmitted to the microcontroller to form a closed-loop control.

The vehicle speed intelligent control system can effectively reduce the occurrence of collisions and rear-end collision accidents, is safe and stable, saves energy, is low in cost, and has a good market development prospect.

Description of drawings

Fig. 1 is a structural block diagram of the utility model system.

Figure 2 is a circuit diagram of the chip regulator control circuit.

Figure 3 is a motor drive circuit diagram.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail.

As shown in Figure 1, a kind of vehicle speed intelligent control system comprises ultrasonic sensor 1 and infrared sensor 2, and described ultrasonic sensor 1 and infrared sensor 2 are connected with analog input circuit 3 respectively, and analog input circuit 3 is connected with single-chip microcomputer 4, and single-chip microcomputer 4 are respectively connected to the driving circuit 5, the voltage stabilizing circuit 9, the display module 7 and the alarm module 8; the driving circuit 5 is connected to the motor 6.

The utility model sends the ultrasonic signal and the infrared signal to the ultrasonic sensor 1 and the infrared sensor 2 through the single-chip microcomputer 4 to collect information respectively. Among them, the collected signal is processed by the single chip microcomputer 4, and acts on the driving circuit 5 of the motor, and the speed of the motor 6 is directly controlled after the debugging of the driving circuit 5. The infrared sensor 2 is used as a closed-loop feedback, and the infrared sensor 2 collects the distance signal of the adjacent car in front. When both the ultrasonic sensor and the infrared sensor have collected signals, the PWM of the single-chip microcomputer 4 is comprehensively adjusted to change the duty cycle, thereby controlling the motor, and the speed of the car can be controlled smoothly.

The speed of the motor is related to the duty ratio of the PWM waveform input to the motor drive circuit. The larger the duty ratio, the higher the motor speed. There are generally two motors in a common car, one for rear wheel drive and the other for front wheel steering, which can be controlled separately by two-way PWM. In the control process, the speed of the vehicle can be controlled in two ways: open-loop and closed-loop. The open-loop control only needs to detect the dynamic data of its adjacent vehicles to directly control the speed of its own vehicle. The circuit is simple and the control is easy. But when the vehicle speed is high, the impact is large and the control accuracy is low; the closed-loop control installs a speed detection device in the vehicle itself, measures the vehicle speed itself, and feeds it back to the single-chip microcomputer, which is used to control the actual vehicle speed. It can accurately control the relative speed of its own vehicle and adjacent vehicles, and can also accurately control its own vehicle speed to prevent overspeeding, which greatly reduces the design risk and improves its practical applicability.

In this system, the ultrasonic sensor can measure a long distance, with high measurement accuracy and simple measurement circuit. The single-chip central control circuit has a wide range of computing data, fast computing speed, high circuit integration, and it has rich I/O interfaces, multiple communication methods, timers, counters, and multi-level interrupt processing capabilities. Great convenience Program design and debugging can output multiple PWM waves at the same time, and control multiple motors to work at the same time; the motor drive circuit adopts an integrated drive chip, the circuit connection is simple, the stability is good, and it can adapt to the pulse width modulation ratio of different frequencies. The device can also realize position detection and control functions.

At the same time, we also designed a voltage stabilizing circuit module, which reduces the interference of the single-chip microcomputer from other signals and ensures the stable operation of the single-chip microcomputer. The display module can accurately display the distance between the running car and the front car and the speed of the running car. When the distance between the two vehicles exceeds the safe distance, the buzzer in the alarm module will sound an alarm, which effectively reduces the occurrence of traffic accidents and achieves the purpose of intelligent control of vehicle speed.

The voltage stabilizing circuit diagram and the motor driving circuit diagram are respectively given below to further illustrate the effect of this system.

As shown in Figure 2, it is a chip voltage stabilizing circuit diagram of the present invention.

In the figure, the power supply is first connected to the circuit through the socket, the pin 2 of the socket is grounded, the pin 1 of the socket is connected to the pin 2 of the switch, the pin 3 of the switch is respectively connected to the pin 1 of the chip LM2940 and LM7805, and the pin 4 of the switch A light-emitting diode D1 and a resistor RD are also connected in series as a power indicator; pin 2 of LM7805 is grounded, pin 3 of LM7805 is connected to the output load, pin 1 of LM7805 is grounded through capacitor C4, and pin LM7805 3 Ground through the electrolytic capacitor C44, the function of the capacitor is to stabilize voltage and filter; the pin 2 of the LM2940 is grounded, and the pin 3 of the LM2940 is connected to the output load, and the pin 1 and pin 3 of the LM2940 are respectively passed through the capacitor C2 and the electrolytic capacitor C22 Grounded for voltage stabilization and filtering.

As shown in Figure 3, there are two BTS7960Bs in the motor drive circuit, which are motor control chips. The PWM1 and PWM2 of each BTS7960B chip are respectively connected to the P2 and P4 pins of the microcontroller; the IN1 and IN2 of each BTS7960B chip are connected to the 5v power supply .

PWM1, IN1 and PWM2 of the first BTS7960B chip are respectively connected to pin 3, pin 2 and pin 6 of the BTS7970 control chip through resistors R12, R13 and R14, and pin 5 is grounded through resistor R16. The pin 7 is connected to the power supply voltage VCC7 and grounded through the capacitor C13, OUT1 and OUT2 are respectively connected to the two ends of the motor; the pin 1 is grounded.

The second BTS7960B chip PWM1, IN2 and PWM2 are respectively connected to pin 3, pin 2 and pin 6 of the BTS7970 control chip through resistors R18, R21 and R22, and pin 5 is grounded through resistor R24. The pin 7 is connected to the power supply voltage VCC7 and grounded through the capacitor C17, and OUT1 and OUT2 are respectively connected to the two ends of the motor; the pin 1 is grounded. The capacitor in the circuit acts as a voltage regulator and filter; the resistor acts as a current limiter. The characteristics of its drive circuit are as follows:

1) It is isolated from the microcontroller 5V to effectively protect the microcontroller;

2) Motor drive output voltage display;

3) Isolated chip 5V power supply (5V can be shared with MCU);

4) Heat sink can be welded;

5) Large current output, the maximum supply current can reach 43A;

6) From the microcontroller to the drive module, use 4 wires (GND, 5V, PWM1, PWM2);

7) The maximum frequency supports 15KHz, exceeding it will cause the chip to become hot and the motor to run abnormally;

8) Board wiring specifications, strong over-current capability;

The embodiment of the present utility model is to gather signal by ultrasonic sensor 1 information, then the signal that gathers is sent in the core processing chip single-chip microcomputer 4, through the processing and calculation of information by core processing chip MC9S12XS128, control the speed of motor 6; The system is powered by a 7.2V DC battery, and the battery is connected to the power indicator, and the power indicator is used to judge whether the circuit is working normally; in order to provide a stable 5V voltage for the core processor, we use LM2940 to stabilize the voltage, LM2940 has Low power consumption, simple circuit, high efficiency and other functions; when the distance between the two vehicles exceeds the safe distance, the buzzer will alarm to remind the driver to pay attention to the vehicle in front; the distance between the vehicle in front and the vehicle can be displayed on the LCD It is accurately displayed on the screen; the motor is controlled by the feedback of BTS7960B and infrared sensor, and two BTS7960B form a full-bridge three-phase drive circuit, which has over-temperature, over-voltage, under-voltage, over-current and short-circuit protection functions.

The above is only a preferred embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, and any person familiar with the technical field can easily think of All changes or replacements should fall within the protection scope of the present utility model.

Claims (6)

1. A vehicle speed intelligent control system is characterized in that, comprises ultrasonic sensor and infrared sensor, described ultrasonic sensor and infrared sensor are connected with analog input circuit respectively, and analog input circuit is connected with single-chip microcomputer, and single-chip microcomputer connects drive circuit, voltage regulator respectively circuit, display module and alarm module; the drive circuit is connected to the motor; Described single-chip microcomputer adopts mc9s12sx128 single-chip microcomputer; The voltage stabilizing circuit includes a socket, the socket is connected to a switch, the switch pin 3 is respectively connected to the pin 1 of the chip LM2940 and LM7805, the switch pin 4 is connected to a light-emitting diode D1 and a resistance RD to ground; the LM7805 pin 2 is grounded, and the LM7805 tube Pin 3 is connected to the output load, LM7805 pin 1 is grounded through capacitor C4, LM7805 pin 3 is grounded through electrolytic capacitor C44; LM2940 pin 2 is grounded, LM2940 pin 3 is connected to the output load, LM2940 pin 1 and pin 3 are respectively connected to the capacitor C2 and electrolytic capacitor C22 are grounded. the 2. The vehicle speed intelligent control system according to claim 1, characterized in that the single-chip microcomputer (4) is respectively connected with an ultrasonic sensor and an infrared sensor. the 3. The automobile speed intelligent control system according to claim 1, wherein the drive circuit comprises two BTS7960B chips connected in parallel, wherein PWM1 and PWM2 of each BTS7960B chip are connected to the single-chip microcomputer respectively; IN1 and IN2 are respectively connected to the power supply. the 4. The vehicle speed intelligent control system according to claim 3, characterized in that, the PWM1, PWM2 and IN1, IN2 of each BTS7960B chip are respectively connected to the pins of the BTS7970 control chip through resistors. the 5. The vehicle speed intelligent control system according to claim 3, characterized in that, the BTS7970 control chip is grounded after being connected to a resistor. the 6. The automobile speed intelligent control system according to claim 3, characterized in that, OUT1 and OUT2 of the BTS7970 control chip are respectively connected to the two ends of the motor; pin 7 is connected to the power supply voltage VCC7 and grounded after connecting the capacitor. the

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