【正文】 optical detectors, pv detector detect rate more than forty percent of figure limit, Don39。t require additional bias electric field and load resistance, no power consumption, having a high impedance. These characteristics of preparation and use of the focal plane array bring great benefits. (3) light emitting Schottky potential barrier detector: metal and semiconductor contact, typically include PtSi/Si structure and form was Schott potential barrier, infrared photon through Si layer for PtSi absorption, electronic Fermi level, obtain energy leap over left cavitation potential barrier into the Si substrate, PtSi layer of electronic was collected, plete infrared detection. Make full use of Si integration technology, facilitate production, with lower cost and good uniformity wait for an advantage, but make it mass (1024 x 1024 even greater) focal plane array to make up for the defect of quantum low efficiency. Have strict low temperature requirements. With this kind of detector, both at home and abroad has already produced as qualitative good thermography. Pt Si/Si structure made of FPA is the earliest IRFPA. Timing counting and traffic calculation Using MCS 51 internal timer/counter for timing, cooperate software delay realizes the timer. This method hardware cost saving, cut allows the reader in timer/counter use, disruptions and programming get exercise and improve. Computation formula is as follows: TC = M C Type in, M for counter touch value, the value and the counter working way concerned. For a traffic intersection, it can in the shortest possible time to achieve maximum 21traffic, even reached the best performance, we call in unit of time to achieve the maximum flow multienergy for cars. Use the equation: (traffic = traffic/time) to represent. Intersection traffic lights used to create the general thoughts Cross the road traffic is traffic laws of the silent mands, is drivers and pedestrians standards of behaviour. Cross the road traffic lights control is the guarantee of traffic safety and the roads of the key. At present, the domestic most cities are adopting automatic red and green lights, it has fixed red light green conversion interval, and automatic switching. They generally by transit and prohibit time control display, red yellow green lights and direction indicator three parts. In the traffic light transit and prohibit time control and display, usually either eastwest and southnorth direction every 50 seconds。 two Either according to the traffic rules, things direction 60 seconds, northsouth direction 40 seconds, time control are fixed. The traffic light time control and display, with a fixed time value in advance petrification in the SCM, every time only in certain period changing alternately. But, in fact, of different time vehicles is very plex circulation conditions, is highly nonlinear, random, also often be think influences. Adopt timing control often causing road effective application waste of time, there is less, the red light green direction vehicle direction vehicle backlog. It regardless of the current number of road traffic due to the actual situation of change, its biggest flaw is that when the road conditions change, cannot satisfy the driver and passersby39。s actual need, light person cause time wasted, the person that weigh directly lead to traffic jams, bring about urban traffic the decline in efficiency. At present, there is a use of fuzzy control technology control method of traffic lights. According to crossroads in both directions vehicle dynamic status, automatic judgment traffic lights to ensure maximum time intervals, traffic, reduce road traffic jams. But unlike timing control, can use digital display the current light color remaining time, so that the driver grasps his driving action, to stop in time or start. 22Figure 3 crossroads driveway shape figure Figure 4 for histograms, writes for north crossroads lamp, the right of the east crossroads lamp, underneath for south crossroads lamp, left for west crossroads lamp. Figure 5 shows the traffic rules for a state chart, set up separately for S1, S2, S3 S4, in this traffic lights, four state for a cycle, circular execution. Figure 4 vehicle histogram Please note that figure S2 state and S4 state, they in a given time interval in four directions can open to traffic, this state can within certain time to an even larger traffic, particularly high efficiency. Outer ring is the north for direction state circulation and inner circle is east for direction state cycle. 23Figure 5 vehicle state chart Based on the above the vehicle of a state chart, can list each intersection of logic table lamp, due to opposite of light of a state chart is same, so we only write adjacent intersections of light of logic table, According to the operation diagram can be seen, the adjacent intersections lamp their status in phase differences 180 176。. So ultimately just write a group of S1, S2, S3, S4 logic state list. As shown in table 3 shows: Table 3 traffic lights cycle logic table S1 state A(P17) B C D E F G H(P10)Logic values 0 0 1 0 1 0 0 0Displays a statusnorthsouth trafficS2 state A B C D E F G HLogic values 0 0 0 1 1 0 0 0Displays a statusnorthsouth left to trafficS3 state A B C D E F G Hlogical value 1 0 0 0 0 0 1 0Displays a statusEastwest throughS4 state A B C D E F G H24logical values 1 0 0 0 0 0 0 1Displays a statusEastwest left to trafficList of 1 representative lights (also represent logic 1), 0 represents the lamp (also represent logic 0), in accordance with the above, can send to the corresponding port logic values.