Numerical control system signal processing methods dial handwheel

手轮的工作原理, 针对其在数控系统应用中表盘手轮存在的问题, 设计了一种结构严谨的表盘手轮鉴相电路和滤波电路,">Abstract : This paper analyzes the working principle of the dial handwheel , numerical control system for its application in the dial hand wheel problems , the design of a structured dial handwheel phase and filter circuit ,
Effectively eliminates signal interference dial hand wheel , hand wheel correctly record the dial pulse signal , and in practice has achieved good results.
Keywords: hand wheel , phase , to shake, CNC system, dial hand wheel

Foreword in the NC system , the cutter micro workpiece on the knife , table follower , machine datum correction of these features is usually done by hand wheel operation to achieve this functionality to the machine operator to bring a lot of convenience , CNC machine tools in making hand wheel is used widely . But handwheel slightly swaying in time , prone to jitter, causing the output pulses are not allowed, cause the machine to malfunction, ranging from causing workpiece scrap , heavy endanger the safety of the operator , so in the machining process, precision and reliability is particularly important. The author in the actual application of numerical control system , summarize, tested a structured dial handwheel signal processing methods .
A handwheel handwheel works , also known as manual pulse generator, which is essentially an incremental encoder is a photoelectric position control components. Figure 1 shows the working principle diagram of the handwheel , the rotation of the handwheel , with the grating disk and the speed of rotation of the rotary shaft , after the detection of components from the light emitting device, the size of the angle it turned into the position and orientation comprising the pulse sequence information in the program can be driven under the control of CNC machine tool axis. Handwheel rotate a scale having a phase difference of 90b , A, B signals , dial handwheel signals. Positive rotation , A phase B, 90b, reverses , B phase leads A phase 90b.
2 signal processing handwheel handwheel output signal processing circuit of discrete components , ASIC , microcontroller , programmable logic devices and so are many implementations. But for multi-axis CNC system , if it is done using discrete components including signal including a series of hand wheel encoder signal , you will need more components , resulting in structural complexity , power consumption increases, decreased stability and other shortcomings. Now often used complex programmable logic device CPLD to implement the handwheel signals Kam phase filtering function. Dial handwheel handwheel signals gives the signal processing circuit structure , which consists of a phase , debounce circuit , delay circuit, 16 reversible counter , the output buffer and the data bus composition. The following functions for each part of the circuit to be described.
2.11 phase circuit schematic phase circuit is to get the hand wheel rotation direction , resulting in the counter direction signal . Shows the working principle of the hand wheel in each signal cycle , A pulse signal pulse and the B signal difference 90b.
2.12 handwheel signal phase , debounce circuitry designed to eliminate interference due to various factors which led handwheel output pulse with clutter , to ensure the reliability and validity of the output signal , the counter counts must be performed before treatment to shake . Generally use two methods to improve the ability to filter out clutter : First, when using the Schmitt trigger input stage , by the waveform shaping by the Schmitt trigger on the ability to filter out clutter ; second is to use multi-level extension the method to accomplish the filtering function . Similarly , the phase commonly used methods may be used : D flip-flop and a gate circuit to achieve. These methods are relatively simple to implement , but the anti-interference ability . Dial signal based on the above analysis, the hand wheel , the hand wheel in order to better achieve the phase discriminator signal filtering work , we use the state machine plus sign determination method . In practical work through trial and error, that the use of this method to achieve phase handwheel debounce work , the effect is better than ever . The hand wheel from the dial signal shows: rotating a scale ideal situation A, B and the signal combination from four states , when the positive rpm , BA status is : 00y 01y 11y 10; when is reversed , BA status is : 00y 10y11y 01. For convenience , so that S1 = 00, S2 = 01, S4 = 11, S3 = 10, dial handwheel handwheel signals given state transition diagram , dial handwheel signals FP and FN as the corresponding forward and reverse state flag , when completed the previous state to the next state transition , the corresponding position 1. If the signal is transferred dial hand wheel or the reverse state transition diagram for the completion four states , with 1 pulse output, the Q = 1, and provides positive rotation , the direction signal D = 1, then anti- D = 0. The following will illustrate the handwheel signals breakdown state transition diagram and using CPLD implementation illustrate dial handwheel signal design process.
When the current state is S1 :
( 1 ) If the previous state is S1, set forward flag FP = 0001, FN = 0001, then Q = 0;
( 2 ) If the previous state of S3, and FP = 1111, then Q = 1, D = 1, the hand wheel forward a scale ;
( 3 ) If the previous state of S2, and FN = 1111, then Q = 1, D = 0, reversing a handwheel scale ;
( 4 ) If the previous state is S4, this state to the inactive state , the reset FP = 0001, FN = 0001, Q = 0, there is interference signal handwheel over, do not count .
S2 is the current state is :
( 1) If a previous state is S4, and FN = 0111, then set FN = 1111, FP cleared handwheel completion signal S2 from the S4 state to state transitions , the middle part of a cycle of the process , the hand wheel scale has not occurred change , Q = 0;
( 2) If a previous state is S1, and FP = 0001, then set FP = 0011, FN is cleared , the handwheel completion signal from S1 to S2 state transition state , the results above;
( 3 ) If the previous state of S3, this state to the inactive state , the reset FP = 0001, FN = 0001, Q = 0, there is interference signal handwheel over, do not count .
When the current state is S4 :
( 1) If a previous state is S3, and FN = 0011, then set FN = 0111, FP cleared handwheel completion signal from S3 to S4 state transition , the middle part of a cycle of the process , the hand wheel scale has not occurred change , Q = 0;
( 2) If a previous state is S2, and FP = 0011, then set FP = 0111, FN is cleared , the handwheel completion signal state from state S2 to S4 conversion process are in the middle of a cycle , the hand wheel scale has not occurred change , Q = 0;
( 3 ) If the previous state of S1, this state to the inactive state , the reset FP = 0001, FN = 0001, Q = 0, there is interference signal handwheel over, do not count .
S3, the current state is :
( 1) If a previous state is S1, and FN = 0001, then set FN = 0011, FP cleared handwheel completion signal from S1 to S3 state of the conversion state , is in the middle of a cycle process , the hand wheel scale has not occurred change , Q = 0;
( 2) If a previous state is S4, and FP = 0111, then set FP = 1111, FN is cleared , the completion signal from the handwheel to the S3 state S4 state conversion process are in the middle of a cycle , the hand wheel scale has not occurred change , Q = 0;
( 3 ) If the previous state of S2, this state to the inactive state , the reset FP = 0001, FN = 0001, Q = 0, there is interference signal handwheel over, do not count .
2.13 dial handwheel signal delay circuit working principle known by the reversible counter , the count before the first determine the direction in which you can use the D flip-flop so that the direction of the handwheel pulse signal lag than one clock cycle.
Conclusions This paper proposed and implemented based on wavelet packet decomposition and SVM diamond pen passive state identification , dial handwheel signals results showed that:
( 1 ) Dresser process acoustic emission signals are more sensitive to the passivation of diamond pen , diamond pen can be used to determine the passive state , and adjust or replace the diamond pen .
( 2 ) Identification of the diamond pen passivated , wheel dressing focus on the acoustic emission signal is high-frequency part , three-layer wavelet packet decomposition of the energy extracted for each frequency band , can effectively eliminate the noise effects and to reflect the feature quantity of Grinding Wheel .
( 3 ) using the radial basis kernel SVM passivation identified, the dial handwheel signal sample size is not the case still get a good recognition results than using BP network has a higher recognition rate. In summary, based on wavelet packet decomposition and SVM method for diamond pen passivation methods are better than the traditional effect , this method has some mechanical fault diagnosis field application prospects . Therefore , glazing robot workspace volume V = P360 (R2m ax - R2m in) (H1m ax - H1m in) (bmax - bm in)
Summary typical sanitary ceramics products glazing process and dial hand wheel signal process requirements, determine the design principles of the robot after glazing , the following conclusions :
( 1 ) Glazing of five degrees of freedom robot joint type robot ;
( 2 ) According to the typical sanitary ceramics products ( ie, one-piece toilet various sizes are selected corresponding limit ) , the dial handwheel signals can determine the structure of each part of the robot glazing dimensions ;
( 3 ) the actual design glazing robot structure size , you should also consider the robot's operation margin ;
( 4 ) the robot work space glazing is formed by four circular arc area of ​​the closed figure , and then multiplied by the distance along the y axis .
2.14 16 reversible counter 16 is the role of reversible counter records the displacement of positive and negative direction handwheel pulses ; to the direction of the phase after the signal as forward, reverse discrimination counts to filtered , pure signal delay count pulse. Buffer output buffer 215 is to prevent the internal signal and the external bus conflict , to protect the external bus.
3 Conclusion In this paper, the signal processing dial handwheel to introduce the concept of a state machine , effectively eliminating the handwheel slightly swaying caused when the signal jitter to provide accurate reversible counter direction signal and count pulses to obtain the correct numerical control system to ensure handwheel count. I have used this method to achieve a HDL language , and in the numerical control system using the hand wheel operation is accurate, made ​​good use of effects. This method is also very versatile , can be used to signal the dial handwheel incremental encoder and encoder signal processing.