XY Table Ballscrew Drive System

Situating frameworks in machine devices of late demands for tall exactness and self altering component to be actualized into the framework in arrange to maintain against different unsettling influence powers. The unsettling influence powers are within the frame of both cutting powers and grinding powers. The point of this paper is to propose a controller specifically Nonlinear Corresponding Fundamentally Subordinate (NPID) to control the position of the framework. The following blunder will be compensated by the NPID controller. The following execution of NPID controller is compared with routine PID controller. The degree of strength of both controllers is quantified based on lessening within the amplitudes of cutting constrain sounds utilizing Quick Fourier Change. It is clear that the normal following execution result of NPID controller exceed the PID controller approximately 8 % to 40 % way better. The finalize plan of NPID controller do give brighter prospect for machining application such as processing prepare. The execution of NPID controller will offer adaptability since the controller are an versatile sort of controller in which it can naturally alter for superior esteem of pick up based on the mistake created from the framework. At last, it is prescribed that in arrange to extemporize assist the NPID controller, control originator may inserted any sort of include on highlights like dead zone compensator and following differentiator into the controller to make strides the following execution. In machine apparatuses application, there are a few controllers have been utilized for the reason of controlling the position of the framework specifically PID controller, Cascade Controller , Sliding Mode Controller and Fluffy Rationale controller to title a number of. The ordinary PID controller offers a coordinate approach to get favored result. All things considered, as the controller confronting diverse sorts of unsettling influence from distinctive sort of unsettling influence source, PID controller tend to face difficulties to control the position and to supply great transitory execution . Typically due to the fix value of corresponding pick up, Kp, Fundamentally pick up, Ki, and Subsidiary pick up, Kd . Hypothetically, those pick up values ought to be shifts when the unsettling influence values are shifted. At that point, the thought of pick up planning controller come in to fathom those issue but it includes a muddled and tiring work. It is since it requires the control creator to physically tuned those pick up values appropriately. A more modern approach like Sliding Mode Control, Fluffy rationale control and other sort of versatile control are able to correct the issue of a framework with changing stack unsettling influence. Shockingly, those present day controllers are not favored in genuine mechanical application due to the complexity and common sense issues. As a result, PID controller is still important and a favored choice in industry much obliged to its useful straightforwardness, taken a toll reasonableness and effectiveness to function. In this paper, the PID controller that intaglio with self tuned nonlinear pick up (known as NPID) is proposed and tried to control the position and following of XY table ballscrew drive framework. The self tuned nonlinear pick up is utilized to compensate the nonlinearity as well as to correct the deficiency in ordinary PID controller. This control methodology is considered since of its basic detailing however it is proficient to fulfill the work that's unfit to be gotten by direct conventional PID controller.

Self-tuned Nonlinear PID (NPID) controller is chosen to control the position of the system. The system identification process has been done in [7]. Basically, the plant is an XY table ballscrew drive system. The transfer function of the plant is as follows:

where Y is the position of the table in millimeter and U is the input voltage signal in volt. The design stages of NPID controller can be divided into 3 parts. The steps namely are : • Stage 1 : Overview on NPID equations and formulae. • Stage 2 : Guidelines to obtain parameters of NPID controller. • Stage 3 : Stability test for NPID controller. In general the suggested nonlinear PID (NPID) controller is developed by a sector bounded nonlinear gain, K(e) that is integrated in series (cascade) with PID controller. Fig. 1 illustrates the block diagram of the NPID control system. The parameters of the traditional PID controller are acquired based on previous work [1] which is based on the desired gain and phase margin. The self tuned gain adjustment, K(e) behave as a nonlinear function of error, e(t) which is bounded in the sector 0 ≤ K(e) ≤ K(emax) as pointed out in (2) and (3). These can be classified as the range of available choice for the nonlinear gain, K(e). The output formed from this nonlinear function is acknowledged as scaled error, fe and the equation of fe is presented in (4). Alternatively, the overall equation of NPID controller can be viewed as in (5).

Figure 1. Block diagram of the NPID controlled system