文献翻译矿井提升机精确测速的微机实现Word下载.docx

1、1 To the microcomputer measured that the fast installment request To the microcomputer measured the fast installment the general request is: Resolution is strong, the precision is high, as far as possible short examination time. 1.1 resolution When carries on the rotational speed examination with th

2、e microcomputer, the resolution with changes was measured that the rotational speed which a survey meter digit corresponds the change quantity expressed. Supposes the rotational speed when become n2 by n1 causes the survey meter value to change a character, represents the resolution with Q:The resol

3、ution size and systems control precision relations are really big, the Q value is smaller, resolution is stronger, systems control precision is higher, it is measures the fast installment an important target.1.2 measured that fast precision Measured the fast precision is refers to measures the fast

4、installment to the actual tachometric survey precise degree. If with n represents the observed value and the actual value difference, n represents the actual rotational speed, % represent the measuring error which expressed with the relative value, thenObviously, % is smaller, measured that the fast

5、 precision is higher; systems control precision will be also higher. The measuring error % sizes decided that in measured the fast parts manufacture precision, and with measured the fast method concerns.1.3 examination time The examination time is refers to between two time rotational speed sampling

6、 the time-gap. The examination times length the control performance influence is very big to the system, if the examination time is very long, then the system will realize the stable fast response with difficulty. The examination time is shorter, is more advantageous regarding systems control perfor

7、mances improvement.2 The microcomputer measured that fast general method By the electro-optical type revolving encoder and elevators axis solid joint, the elevator retransmits the certain amount every time （1080） the signal impulse, takes down the pulse number by the counter, and gives computer proc

8、essing to realize the microcomputer to measure fast. Commonly used measured that the fast method mainly has the following two kinds.2.1 The M law measures fastThe M law measured that fast is reads the pulse integer which in the equal time-gap the revolving encoder sends out to figure out the rotatio

9、nal speed. The pulse number which sends out in the same time internal rotation encoder is different; the observed value is not same. The M law measured that fast schematic diagram as shown in Figure 1.By the counter the pulse counting which transmits to the revolving encoder, timer every other time

10、T sends out an interrupt request to CPU, extracts corresponding according to the counting values size the rotational speed. The revolving encoder retransmits pulse 1080 every time, altogether has m pulse in the T time, then the rotational speed is:This kind measured that the fast method is by the co

11、unting value m size reflection rotational speed height, thus is called the M law to measure fast.（1） Resolution May result in according to the resolution definition by type （3）:Obviously, the M law measured fast when the resolution has nothing to do with the speed size, concerns with rotational spee

12、d sampling period T.（2） measured that fast precision When measures using the revolving encoder fast, its measuring error decided that concerns in encoders manufacture precision and with the rotational speed size. Supposes between the revolving encoder two neighboring pulses the angular deviations ar

13、e. p%, an examination cycles counting value is m, then the measuring error is:The rotational speed is lower, m is smaller, the measuring error is bigger, measured that the fast precision is lower. Along with the RPM drop measured that the fast precision reduces is the M law measures a fast shortcomi

14、ng.（3） Examines the time: Is equal to survey cycle T.2. 2 T law measured that fast T law measured fast is determines between the revolving encoder two output pulses the time interval to calculate the rotational speed to measure the fast method. The time survey carries on the counting by a counter to

15、 the known frequencys clock pulse to obtain, the T law measured that fast schematic diagram as shown in Figure 2.The revolving encoder outputs a pulse through the microcomputer connection sends out an interrupt to CPU, after the CPU response, to read out the counting value every time from the counte

16、r, then figures out the rotational speed by the counting value. Supposes the clock rate is f, counting values between two pulses are m, then rotational speed n is:May see, the T law measured that fast is just the opposite with the M law. Rotational speed higher survey meter value m is smaller.Suppos

17、es, because the rotational speed counting value becomes m-1 by m, according to resolution definition:By type （7）, Q value size and rotational speed related, the rotational speed is smaller, m is bigger, Q is smaller, measured that the fast installment resolution is stronger. The T law measured that

18、the fast merit lies in the low speed section to have the strong resolution to the rotational speed, thus may enhance the low speed the control performance.（2） Measures the fast precisionMeasuring error is equal to the angular deviations between the revolving encoder two pulses p %, namely measuring

19、error:It only decided that in encoders manufacture precision, with is measured the rotational speed to have nothing to do with, it compared to the M law measured that the fast precision must miss.（3） examines the time: Because the revolving encoder retransmits 1080 pulses every time, therefore betwe

20、en two pulses time intervals are:Type （9） indicated that the T law measured the fast examination time changes along with the rotational speed.3 Mine pit elevator to tachometric surveys request The mine pit elevators movement process is a periodic process. Generally elevators promotion cycle includin

21、g the acceleration, the constant speed, the deceleration, crawling, stops five stages. In five stages, elevators running rate has the very wide difference. Below gives the Anhui Province some ore elevator movement the speed chart, see Figure 3. May see by the speed chart, in the acceleration leg and

22、 the deceleration section elevators speed is one process which changes unceasingly according to certain acceleration or the retarded velocity, constant speed Duan Yijiao the high running rate movement, the crawling section speed relative says must be much slower, only then 0.4m/s, generally speaking

23、, the elevator movement process is a speed the process which changes unceasingly in the wide range, if wants to realize the microcomputer to measure accurately fast, then measured that the fast method must satisfy in the high speed and compares the low speed section to be able the correct measuremen

24、t request.In order to safeguard the elevator movement the high security, in elevators each kind of protection, has the constant speed section too fast protection and the deceleration section too fast protection, the constant speed section running rate like surpasses highest rotational speed Vm 15%,

25、elevator safety arrestment; In deceleration section movement, if determines the speed to surpass given value 10%, also will implement the safety arrestment. Therefore, to reflect in the elevator movement accurately the speed condition, realizes the control system security, reliably, to move continuo

26、usly, requests the speed which the microcomputer determines to be accurate, can satisfy certain precision.4 The elevator measured precisely fast M/T law By above may know, elevators velocity measurement request has the high precision, can reflect in the elevator movement accurately the actual rotati

27、onal speed. The fore-mentioned M law measures fast, low speed Duan Cesu the precision is quite low; The T law measures fast, low speed section rotational speed resolution is strong, but it measured that the fast precision is also much worse than the M law, they use in the elevator measuring the fast

28、 insufficient ideal; But M/T measured that the fast principle synthesizes two methods the merits, both may the low speed section reliable surveying fast, and also has the high resolution in the high speed section, adapted the elevator to the velocity measurement request. The M /T principle measured

29、that the fast principle sees Figure 4.And T0 by a timer fixed time, examination cycle T had finished after T0, the pulse generator outputs first pulse decided that namely T=T0+T, m1 is the pulse number which in the T time the encoder sends out, m2 is in cyclical T to the clock pulse counting value. The rotational speed expression is:A in the formula f clock pulse frequency; the 1080yi encoder retr