| Unmanned car, as the combination of modern high-technology and car technology, is the mainstream of the future car industry. Generally speaking, it utilizes certain supervising technology such as vehicle-mounted sensor,global positioning system,laser scanner and radar to perceive the information such as surrounding environment, position of the car, obstacles in the way. After analyzing, classifying and judging, the information can serve to direct the driving of the car, making it move safely, correctly on the road. Research about this kind of products has begun abroad since 1970's and now has come to practical usage. However, today's research about unmanned car focus more on the exploration of the one that drives on express high way or in city environment but less on that in some particular situations.This new designed unmanned touring car is specially applied to wild animal zoos. With large space, long touring route and freely-raised animals in it, tourists are seldom required to visit the zoo by foot or cycling but using a touring car. What's more, without any other vehicles and passengers, the road condition is comparatively better and cars there drive slowly (about 7km/h) and steadily for viewing. Thus, auto-touring cars have no need to function in many aspects and no high driving technique is required. In short, their costs are low but worthwhile to be explored.Given that roads in the zoo undulate little and obstacles are few, touring cars even do not have to be stopped suddenly or started frequently. Above that, few instant starts, sudden accelerations or climbing with certain weight are needed and it requires no high Instantaneous power,no quick dynamic response, etc. As indicated, BLDCM suits the driving system of the electric-powered car most as it is featured by its big power density, high efficiency, quick response, small inertia and volume.Considering that roads in the zoo are also flat and short, cars there always drive slowly and steadily even just like driving with rated load。So, to use two 600w BLDCM to start the car in the way of double-front wheel Shaft drive can make our starting machine simple, light, cheap and easy to be maintained.Apart from that, the auto-touring car is a kind of spot-detecting cars. It can take its passengers circling automatically along a closed route and stop when it reaches to the parking spots which are designed beforehand. In the wild animal zoo, there may be some animals appearing suddenly in the way, so the car should also have the ability to stop whenever it meets obstacles. Accordingly, to adopt the most advanced, low-exhausting, high speed, Chip hardware resource-rich, high performance-price ratio ATMEGA16 microcontroller from AVR series as the control system of this touring car is the best choice. Ranked as the most advanced series of microcontroller , it is particularly designed for battery-powered, portable and motor-started.These designs indicate that we can install a spring contact switch under the seat and diffuse reflection type infrared sensor under the base of the car. Besides, another two sets of infrared sensors are fixed in the tail of the proceeding car and at the head of the following car a set of infrared receiver and two ultrasonic sensors are added.Meanwhile, as the cars are orderly circling the route, it's better to lay a black line in the middle of the route which can help the car to detect and stop automatically at the parking spots which are marked by another black line vertical to the straight one.When the passengers get on the car, the spring switch under the seat is on and the signal is delivered to the microcontroller which directs the car to start and function. During the driving, the microcontroller keeps on reading the 3 signals from the infrared sensor to alternate the speed, making the touring-car turning left or right to follow the route and keep along with the black line all the time.At the same time, the microcontroller continually reads out the signals from the long-distance ultrasonic distance measurement sensor and the obstacle-detecting infrared sensor in the proceeding car. When the ultrasonic distance measurement sensor find out obstacles but infrared sensor receives no infra-red signal from the proceeding car, the microcontroller then take the obstacle as an animal and immediately make the car stop at a long distance. When the infrared sensors receives signals, the microcontroller then take it as a car and turn to the low speed until the distance from the proceeding car reaches to the limited one. After that, it stops the car nearby.When the car arrives at the parking spot and meets the horizontal black line, all the 3 spotting infrared sensor act together. Then the microcontroller makes the car stop to let the passengers down. Sometimes other parking cars may be there, and then it will stop to wait for a position. After the parking cars move away, they go forward. If there are no passengers, the microcontroller will make the car move slowly until it gets to the horizontal line or meet the distance limit with the proceeding car; if passengers are all on, it will neglect the line and move forward after no obstacles are found.The touring cars are powered by battery, and they move slowly with no danger of being crashed by other force. Thus, in order to save the energy and continue a longer distance, the lighter its weight, the better. The best solution is to wisely choose the material of the outfit. Nowadays, aluminum alloy material and other compound materials are frequently applied but the costs are always too high. As a result, with the aim to reduce the cost under the preconditions of safety, we use engineering Plastics to make the outfit.As a touring car, its outlook should be a modern and amicable one. And the streamline appearance, with a gentle curve and simple design, reduces the cost and the difficulties of producing while remaining attractive.The car height should be as low as possible to help to lay down the center of the gravity and move steadily while at the same time appearing to be nice-looking. Besides, no window is installed in the car to enlarge the horizon and lighten the weight. Meanwhile, it's designed to hold 4 people with 2 rows of seats in it to make it smaller. And last, since it is a non-human driving car, no steering wheel but a transparent sunshade ceiling is needed.In addition, unmanned touring cars are situated in a colorful natural environment, but the environment is usually dominated by low-purity natural colors. Therefore, the main color of touring cars is supposed to be various high- brightness,low-purity color alignments of gray, pink and gem-like blue to make touring cars easily recognizable and not too bright at the same time, hence less or no irritation to animals in the zoo.
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