Prapart Ukakimapurn

Digital Technique to Generate Variable and Multiple PWM Signals

In this paper, we present a digital technique to generate pulse width modulation (PWM) signal using counters, comparators, and latching circuits implemented by Verilog HDL program based on FPGA. The proposed technique can simultaneously generate variable and multiple PWM outputs with parallel processing. Setting each reference-input signal can independently and easily vary the pulse width of each generated signal. The FPGA-based implementation can minimize the size of hardware. The communication can be easily done via a personnel computer. Application example in the design of the proposed technique as the parallel processing is also included.

A simple technique to modeling and simulation four-axe robot-arm control

This paper presents modeling and real-time simulation programs that were developed for robot arm control. The technique analyzes the safety path, working area and step motion of robot. The implementation of experimental forward and inverse kinematics control method as Matlab m-files is described. The visualization and animation capabilities of Matlab provide a realistic perception of behavior of the test beds without robot or before send the command to robot. Control mode in manual and automatic by a joystick and library file via PC respectively.

The technique to generate firing signal of converter for linear dc output

The firing angle adjustment of ac-dc converter that adjust firing angle proportional to control signal. The dc output voltage is not linear. This paper presents the technique to generate the firing signal for ac-dc converter which has linear dc output voltage. This technique decoded the arccosine value as binary data and save in ROM, before compare with control signal. All digital circuits and ROM were constructed using field programmable gate array (FPGA) and Verilog Hardware Description Language (Verilog HDL) so that the proposed technique has small size and ease of implementation. The experimental results show the dc output voltage and output waveform that agree with the design. Moreover, this technique can be applied to multi-output for dual converter and 3- phase system.

A technique for mechanical adjustment of DC motor by virtual model

This paper presents a technique to adjust and improve mechanical responses of DC Motor. The proposed technique uses math model for simulation to observe the transience and steady state response in no-load condition. Information derived from the simulation results can be applied to compensate the mechanical loss, inertia, viscous friction by feeding electrical energy. The test results of the compensation technique in this research can adjust and improve the response of speed and torque under reasonable tests. Moreover, this technique can apply to virtual load for Dynamometer.