Saturday, October 27, 2012

Labeling For Hardware and Software

Labeling for hardware and software
  • Labeling of hardware and software in order to make it clear and easy to understand during explanation to examiner.


          • motor
          • Signal output
          • Sensor
          • Dc motor
        • PID
        • Set point (knob or desired value)
        • Justify waveform (PWM, SENSOR, OUTPUT, ACTUAL OUTPUT)
        • Output value (SPEED, FREQUENCY, DUTY CYCLE)

Monday, October 15, 2012

Conclusion For The System


  • The objective of this project is to understand the PID controller and the tuning process for Industrial control system.  Labview Software is very powerful and one of SCADA system which can monitor and controlling the process.This project are develop the understanding in science and technology that provide a wide range scope of applications  of  high  performance  DC  motor   to drives  in  area  such  as  rolling  mills, chemical  process,  electric  trains,  robotic  manipulators  and  the  home  electric appliances require speed controllers  to perform  tasks. DC motors have speed control capabilities, which means  that  speed,  torque  and  even  direction  of  rotation  can  be changed at anytime to meet new condition.
  • By design the block diagram, we can understand about the function of it controller, system plant, final control element, sensor and set point. The  goals  of  this  project  are  to  design  and  implement  speed measurement  for  the  DC  motor  using  LabView. Labview is the software that useful for engineering in industries of Malaysia.  So, this assessment practices us to be general with control system in industrial
  • For the key finding, the PID controller in LabView used to compare the desire speed and actual speed. Then, it will send the signal to motor to make sure that it running in same speed as a desire speed.  The PID controller can be reduced the rise time since the motor start to running and follow the desire speed. It also eliminates the steady-state error by using integral controller and lastly it increase the stability of the system by using derivative control. The error is generated by disturbance that can make the speed of motor decreased because of the friction between slotted disc and optical encoder sensor. Finally, this project was successful constructed by using PID controller in LabView and to proved that this project is functioning is, the actual speed will follow the set point with having rise time, steady state error and stability.
  • system in labview is much batter when compared with the microcontroller in DC motor controller and the disadvantages of the labiew is too expensive to have DAQ card. Therefore, only big company and industry used Labview software as their monitor and controlling process in system. For example,company like Texas Instrument(the biggest semi conductor company).
  • We have some factors to be considered in our system, which is:
1)         PID cycle time
2)         Motor speed
3)         Encoder resolution
4)         PWM frequency
5)         Eliminates code tuning

6)         Maintains accurate PID timing



Wednesday, October 3, 2012

Analysis From Result


·         Discussion on result
             
  • On the LABVIEW software, the set point of desire speed is set and controlled by the knob. The range of the speed motor that can be process in this system is in 1200-2400 RPM. Thus, this range of speed is in the operation of 0-100% duty cycle on PWM. The actual measurement speed from the sensor will runs through the set point value but it will take certain time to ensure the system error running in no steady state error. 

  • The steady state error that controlled and corrected by PID algorithm is based on the operation with significant number of Kp, Ki and Kd. The manual tuning that been made for this project is Kp = 0.6, Ki = 0.05 and Kd = 0.04.  This number of gain has been set based on the manual tuning by try and error process and some calculation that have been done when the system is running.

  •   The results show that the motor can run by controlling the desire speed of the setpoint. The system can running accurately from the set point speed with no steady state error after a certain seconds. By injecting the output process from the PID controller to the PWM by controlling the duty cycle of the PWM, the motor will run with desire speed based on the voltage needed that equivalent to the desire set point speed that has been calculated by PID algorithm based on the current steady state error that occurred to the system.

  • However, there been a bit of non proportional measurement of 10% duty cycle with 20% duty cycle. The frequency output for 10% duty cycle is 45.94 Hz while 20% duty cycle produces 200.50 Hz. This attenuation of measurement is caused by the friction that consider as mechanical disturbance and this disturbance will produce error to the readings. It will occur to the system when the motor is running low speed because the force of rotation is low to encounter the friction force. Hence, the system will not produce an accurate output when running at low speed