超声波的优点很多，频率高、波长短、绕射现象小是它的主要特点，在方向性尤

Many of the advantages of ultrasonic high frequency, wave length, small diffraction phenomenon is its main characteristic, especially in directional and easy to obtain a higher concentration of acoustic energy. Therefore, in daily life in the region ranging ultrasonic ranging is more common. Such as underwater sonar and fishing on the military aspects of use is very wide, as well as to measure seabed topography and other transportation speedometer. <BR>This design is based on an ultrasonic obstacle avoidance SCM trolley. Ultrasonic detection module, the PWM pulse width speed design, digital display program is an important part of this design, part of this detailed description. Selection STC89C52 microcontroller as the control of this design by using ultrasonic sensors to detect whether there is an obstacle ahead, there are obstacles MCU will receive the last data transfer in order to carry out a series of backward turn left obstacle avoidance schemes. Trolley is to be driven by two DC motors. While using PWM system to control the speed of the advancing speed of the car, in order to achieve the turning function. It can automatically identify and implement steering functions when the car encounters an obstacle.

Although I'm not as brave as Tomberg, I think there are other ways. For example, take more of the mass transit. Or less air-to-air and more natural wind. After all, not everyone can do it like her. ...

Ultrasound has many advantages, such as high frequency, short wavelength and small diffraction. It is especially prominent in direction and easy to obtain concentrated acoustic energy. Therefore, in daily life ranging this area of ultrasonic ranging is relatively common. For example, underwater sonar is widely used in military and fishing, as well as traffic velocimeter for seabed geomorphology measurement.<BR>This design is a kind of ultrasonic obstacle avoidance car based on MCU control. Ultrasound detection module, PWM pulse width speed regulation design and digital tube display program are the important parts of this design. This part is introduced in detail. STC89C52 single chip computer is selected as the control core of this graduation project, and ultrasonic sensors are used to detect whether there are obstacles in front of the system. If there are obstacles, the single chip computer will receive the data transmitted in the past so as to make a series of obstacle avoidance plans. The car is driven by two DC motors. At the same time, PWM system is used to speed the car so as to control the speed of the car, so as to achieve the function of turning. When the car encounters obstacles, it can automatically recognize and realize the steering function.<BR>