數(shù)控車床主傳動(dòng)系統(tǒng)畢業(yè)設(shè)計(jì)外文翻譯-資料下載頁
2025-06-27 09:37本頁面
【正文】 enefit from the advanced processing power of the ‘240 include: Industrial motor drivesPower inverters and controllersAutomotive systems, such as electronic power steering , antilock brakes, and climate controlAppliance and HVAC blower/ pressor motor controlsPrinters, copiers, and other office productsTape drives, magnetic optical drives, and other mass storage productsRobotic and CNC milling machinesTo function as a system manager, a DSP must have robust onchip I/O and other peripherals. The event manager of the ‘240 is unlike any other available on a DSP . This applicationoptimized peripheral unit , coupled with the high performance DSP core, enables the use of advanced control techniques for highprecision and highefficiency full variablespeed control of all motor types. Include in the event manager are special pulsewidth modulation (PWM) generation functions, such as a programmable deadband function and a space vector PWM state machine for 3phase motors that provides stateoftheart maximum efficiency in the switching of power transistors.There independent up down timers, each with it’s own pare register, support the generation of asymmetric (noncentered) as well as symmetric (centered) PWM waveforms.OpenLoop and ClosedLoop ControlOpenloop Control SystemsThe word automatic implies that there is a certain amount of sophistication in the control system. By automatic, it generally means That the system is usually capable of adapting to a variety of operating conditions and is able to respond to a class of inputs satisfactorily . However , not any type of control system has the automatic feature. Usually , the automatic feature is achieved by feed.g the feedback structure, it is called an openloop system , which is the simplest and most economical type of control lies in the fact that one may not know the exact characteristics of the further ,which has a definite bearing on the indoor temperature. This alco points to an important disadvantage of the performance of an open loop control system, in that the system is not capable of adapting to variations in environmental conitions or to external disturbances. In the case of the furnace control, perhaps an experienced person can provide control for a certain desired temperature in the house。 but id the doors or windows are opened or closed intermittently during the operating period, the final temperature inside the house will not be accurately regulated by the openloop control.ClosedLoop Control SystemsWhat is missing in the openloop control system for more accurate and more adaptable control is a link or feedback from the output to the input of the system . In order to obtain more accurate bontrol, the controlled signal c(t) must be fed back and pared with the reference input , and an actuating signal proportional to the difference of the output and the input must be sent through the system to correct the error. A system with one or more feedback pat(s like that just described is called a closedloop system. human being are probably the most plex and sophisticated feedback control system in existence. A human being may be considered to be a control system with many inputs and outputs, capable of carrying out highly plex operations.To illustrate the human being as a feedback control system , let us consider that the objective is to reach for an object on aperform the task. The eyes serve as a sensing device which feeds back continuously the position of the hand . The distance between the hand and the object is the error , which is eventually brought to zero as the hand reacher the object. This is a typical example of closedloop control. However , if one is told to reach for the object and then is blindolded, one can only reach toward the object by estimating its exact position. It isAs anther illustrative example of a closedloop control system, shows the block diagram of the rudder control system ofThe basic alements and the bloca diagram of a closedloop control system are shown in fig. In general , the configuration of a feedback control system may not be constrained to that of fig amp。 . In plex systems there may be multitude of feedback loops and element blocks.第 頁 共 10 頁
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