近代倒車雷達與車用網路之設計與應用

Abstract

本論文主要探討在近代汽車產業中開發的倒車雷達技術--PAS (Parking Assistance System，停車助手系統)和汽車網路CAN (Controller Area Network)兩者之結合並應用於現今的汽車產業中。利用MYSON公司提供的倒車雷達實驗公板 (CS8960 PAS EV BOARD)及Single CAN Controllers (MCU_CS8961)，透過實驗室自行製作的實驗電路板 (CS8961 test BOARD)，來撰寫韌體程式去控制MCU_CS8960及MCU_CS8961這兩顆Micro-controller。在應用中，我們讓倒車雷達實驗公板上的Sensor發出超音波，在偵測到待測物後產生一個回波，並透過MCU_CS8960中所嵌入的8051核心中的外部中斷及計時中斷計算待測物的距離，再以UART的訊號格式傳給MCU_CS8961，並使MCU_CS8961 將所測到的待測物距離，以CAN的訊號格式傳到CAN BUS網路上，並實際傳送到SAAB 95 SID (System Information Display)上去顯示，同時，倒車雷達實驗公板上也會發出警示聲響，警示用路人。 在本論文的貢獻上為我們修改了倒車雷達實驗公板上的放大電路，使其可以得到最好的訊號╱雜訊比，並使用一根塑膠水管當作我們的待測物（高約1.6公尺，直徑約為7公分），使其可以精確地量測到此待測物於2.5公尺處，若將待測物更換為一片木板，更可以將量測的距離擴大到8公尺遠。

The main purpose of this thesis is to explore the techniques of combing PAS (Parking Assistance System) and CAN (Controller Area Network) for modern automobiles. With the MYSON provided PAS mother board (CS8960 PAS EV BOARD) and Single CAN Controllers (MCU_CS8961), we design the test board, which is called “CS8961 test BOARD”. The firmware program is also designed to control the micro-controllers, MCU_CS8960 and MCU_CS8961. In our implementation, we let the sensors of CS8960 PAS EV BOARD to generate the ultrasonic signal first. When the ultrasonic signal is touched the obstacle, we will get a feedback signal. Then we use the external interrupt and timer interrupt in MCU_CS8960 to find the distance between the PAS sensor and the obstacle. After we get the distance, we send the distance in ASCII code using UART protocol to the MCU_CS8961. Finally, we use MCU_CS8961 to translate the data protocol of distance into CAN protocol and transmit it to the CAN bus. In addition to the above implementation, we also utilize the SAAB 95 SID (System Information System) as the display unit in CAN BUS. The CS8960 PAS EV BOARD will also sound the buzzer for warning purpose. The contribution of this thesis is we modify the amplifier circuit of PAS mother board. And we can get the best Signal/Noise ratio after modify the circuit. We use a plastic tube as the obstacle which high approximately 1.6 meters and the diameter about 7 centimeters. Then we can measure the obstacle precisely at 2.5 meters. If we change the obstacle as a wood plank, and we can measure the obstacle precisely at 8 meters.