Communication servo electric machinery and machines and tools of report of drive dc servo have good timing performance, in 90 age reaching at the beginning of 80 time, in the circumstance that asks timing performance is higher, the application of system of timing of dc servo electric machinery holds dominant position all the time. But the defect that its put in a few solid to have however, namely: ● brush and commutator are easy wear away, maintain troublesome ● structure complex, production difficulty, cost is high and communication servo electric machinery does not have afore-mentioned defect. Fall in similar volume especially, the output power that exchanges servo electric machinery raises 70% of 10% ～ than dc machine, and accessible rotate speed is higher than dc machine. Accordingly, people is seeking plan of timing of alternating current machine to replace the plan of dc machine timing all the time. The key with transducer implementation pressure regulating frequency conversion is inverter control end obtains a requirement to control weaveform (like SPWM wave) . The implementation means with ● undee control (the control means of electric machinery timing) phasic control; Arrowy quantitative change changes control; PWM control; Field control; The implementation plan of servo of feed of closed circuit of ● of servo of feed of closed circuit, half closed circuit is classification and diagnostic imitate system, numeric system. Imitate system: Characteristic: Interference rejection capability is strong, won't bring about deadly misoperation because of peak value error commonly. Appearance of usable and groovy instrument (oscillograph, avometer) read directly take news, hold the fundamental condition that the system works at any time easily. Difficult to depart of a confusion of voices of weak signal letter, control precision rise be restricted. Get easily around 0 o'clock the influence of temperature drift, make the position controls generation drift error. The structure of adjuster of the position, speed and parameter adjust difficulty, the ability that gets used to laden change is poorer. Imitate system this kind of intrinsic defect, make it satisfies requirement of pilot of servo of high accuracy position very hard, already was replaced by digital servo place gradually at present. Numeric system: Feature: This kind of system is to point to at least control of its position annulus and adjust use a number to control a technology, accession buy statement and feedback signal are imitate signal converts no longer digital signal (signal of logistic n pulse) system. Characteristic: How to grow what can count word information through increasing, will satisfy the control precision of the requirement. To logistic report the following drift, noise does not grant part of the day should, fixed position precision can get assuring adequately at 0 o'clock. Undertake easily modification to its structure and parameter (ask according to control) , and undertake with the computer data is exchanged easily. When noise peak value is more than logistic n, what logarithm occupies is the most exalted with lowest interference makes mistake the program is identical, this kind of mistake may cause the harm with deadly system. The digital circuit of deferent data asks to have very broad frequency band. Go up in order to assure pulse, drop the edge has enough abrupt degree. Restrain interference, prevent data to make mistake, it is the key with digital servo successful design. Form: In this system, the control of positional closed circuit and adjust operation is main by deviation tally (it is reversible tally commonly) finish with D/A. Flexible poor: The system is formed by hardware completely, make its each adjuster parameter is adjusted in Electromechanical couplet after deciding, originally to come down surely, not easy change, the positional servo with this pair of laden inertia not big change (control like feed of lathe tool carrier) , the control property that can acquire satisfaction points to. And older to certain and laden inertia system, it is very difficult inside whole range (laden inertia changes) the control result that achieves satisfaction. 0 float will affect precision: This kind of system relies on D/A, the digital quantity that exports positional adjustment is changed into imitate voltage to make speed command signal. Offer speed servo unit, accordingly, its zero shift will affect fixed position precision. The positional control of this kind of system uses half software of ● servo soft hardware composition, speed control still uses imitate means, if plan institute shows,the system comprises: Characteristic: Interference rejection capability is strong, won't bring about deadly misoperation because of peak value error commonly. Appearance of usable and groovy instrument (oscillograph, avometer) read directly take news, hold the fundamental condition that the system works at any time easily. Difficult to depart of a confusion of voices of weak signal letter, control precision rise be restricted. Get easily around 0 o'clock the influence of temperature drift, make the position controls generation drift error. The structure of adjuster of the position, speed and parameter adjust difficulty, the ability that gets used to laden change is poorer. Imitate system this kind of intrinsic defect, make it satisfies requirement of pilot of servo of high accuracy position very hard, already was replaced by digital servo place gradually at present. Numeric system: Feature: This kind of system is to point to at least control of its position annulus and adjust use a number to control a technology, accession buy statement and feedback signal are imitate signal converts no longer digital signal (signal of logistic n pulse) system. Characteristic: How to grow what can count word information through increasing, will satisfy the control precision of the requirement. To logistic report the following drift, noise does not grant part of the day should, fixed position precision can get assuring adequately at 0 o'clock. Undertake easily modification to its structure and parameter (ask according to control) , and undertake with the computer data is exchanged easily. When noise peak value is more than logistic n, what logarithm occupies is the most exalted with lowest interference makes mistake the program is identical, this kind of mistake may cause the harm with deadly system. The digital circuit of deferent data asks to have very broad frequency band. Go up in order to assure pulse, drop the edge has enough abrupt degree. Restrain interference, prevent data to make mistake, it is the key with digital servo successful design. Form: In this system, the control of positional closed circuit and adjust operation is main by deviation tally (it is reversible tally commonly) finish with D/A. Flexible poor: The system is formed by hardware completely, make its each adjuster parameter is adjusted in Electromechanical couplet after deciding, originally to come down surely, not easy change, the positional servo with this pair of laden inertia not big change (control like feed of lathe tool carrier) , the control property that can acquire satisfaction points to. And older to certain and laden inertia system, it is very difficult inside whole range (laden inertia changes) the control result that achieves satisfaction. 0 float will affect precision: This kind of system relies on D/A, the digital quantity that exports positional adjustment is changed into imitate voltage to make speed command signal. Offer speed servo unit, accordingly, its zero shift will affect fixed position precision. The positional control of this kind of system uses half software of ● servo soft hardware composition, speed control still uses imitate means, if plan institute shows,the system comprises: Positional pilot software can come true by the CPU of NC device now, also can come true by the CPU that takes oneself on positional control plate. Positional pilot adjusts operation part comes true by software, added flexibility: (1) the parameter of adjuster can be revised through undertaking, set; (2) adjust algorithm can use more complex algorithm, in order to improve control performance (change structure, change gain) ; (3) can increase a lot of auxiliary functions (breakdown is diagnosed, pulse equivalent commutation) ; (4) zero shift can undertake compensating through software; Because this is planted,speed unit of the system still is imitate model, the problem that exists in complete hardware system was not solved apparently, the core parameter that is like it (speed, electric current) the digit with converter of the D/A in positional annulus still is fixed. Accordingly hard generous of be used to of load of give attention to two or morethings changes. Nevertheless, because use software to adopt measure of a few compensation, this makes the positional control precision of servo of half software position and control function want prep above complete hardware positional servo. Control of the personal computer position in the graph, speed can be only personal computer already, can be double personal computer (one is positional control, another is speed control) . The personal computer in passing a system constant by sheet piece machine will form. As a result of the application of personal computer, make systematic control more quick, its characteristic is: The structure of adjuster of the position, speed and parameter can press working environment to undertake switch automatically, the made ability that gets used to laden change increases significantly, application optimizes theory to still can make the parameter automation of adjuster, make system but the execution with different drive is mechanical, generalization rate rises greatly. The others is the same as half software system. The output of this kind of system is changed into imitate voltage to serve as voltaic instruction to send toward annulus of imitate electric current through D/A, such, the zero shift that imitate measures can make voltaic instruction produces little change only, general the moment that this kind of change can't produce drive servo electric machinery to move, also won't control precision to produce undesirable effect to the position. Still secure as a result of the structure of voltaic annulus and parameter, still cannot control strategy through personal computer change so, in order to achieve idealer control result. Because this system work is reliable, the structure is compact, control function also narrates two kinds of systems before excel, make it is in since 80 time metaphase hand in, dominant position was held gradually in the product of dc position servo, make the first selection plan of positional servo. Since servo of position of word of ● total number is born with software position servo oneself, replace the job of hardware at present as far as possible with software, in order to reduce cost, improve performance. As the electronic semiconductor device that can use logistic n control to be connected directly -- power transistor, power field leads the commercialization that should be in charge of, and high-powered sheet piece the occurrence of machine, make the implementation of servo of position of total number word becomes reality. All control of the system adjust finish by software entirely, the wide modulation of arteries and veins that outputs logistic n directly finally controls amplifier of transistor of signal drive power, undertake controlling to servo electric machinery, the position that finish controls the job. All software of adjuster changes the new-style control method such as a lot of control thoughts in making control theory and method, for example: Rash club control, from adaptive control, change parameter control, change control of system of structural control, nerve network control, ambiguous control, expert is waited a moment. Be optimized automatically and diagnose automatically of breakdown what still can finish parameter etc, make the system controls function to be able to get rising further. CNC Milling