Analyzing and Controlling a Cruise Control System using MATLAB and Simulink

This Assignment assesses the following module Learning Outcomes (from Definitive Module Document):

• LO1: explore instrumentation techniques, standard control terminology and basic control strategies
• LO2: examine transducer selection criteria and operating principles and aero/auto/motorsport control applications;
• LO3: select appropriate transducers, actuators and instrumentation systems;
• LO5: setup open, feed forward and closed loop systems, tune PID controllers and simulate control systems using computers.

Note that, when the engine produces 500N of force (input), the car will reach a maximum speed of 11.1 m/s (25 mph). Using MATLAB and Simulink, you are required to identify and comment on the behaviour of the OPEN loop velocity response of the cruise control system. This will be achieved by conducting the Open Loop Step Response and Open Loop Nyquist Plot and, based on your understanding of control systems, comment on the stability of the Closed Loop system.

Following this, the cruise control system will be required to achieve the following characteristics:

• Overshoot less than 10%
• 95% settling time less than 7 seconds
• Steady-state error less than 0.1

Implement either a P, PI or PID controller to the velocity response in order to achieve the above characteristic requirements, displaying the Closed Loop step response in your report and critically analysing the suitability of the chosen controller with regards to the above characteristics.

You will also need to link in instrumentation panels from Simulink to show how the driver would see these responses in real-time and comment on these in the report. In addition, comment on the type of sensors that would be used in the vehicle in order to determine whether the desired velocity had been reached. School of Physics, Engineering and Computer Science

Finally, with the chosen controller implemented, produce a Nyquist Plot and, based on your understanding of control systems, comment on the stability of the system.

• The identified Overshoot, 95% Settling Time and Steady State Error of the Open Loop response of the vehicle before the implementation of a suitable controller, assuming an input force of 500N.
• The implementation of a P, PI or PID Controller, critically analysing the suitability of each controller and whether they would be suitable for the closed loop response of the vehicle, assuming an input force of 500N
• Included instrumentation panels, commenting on the suitability of these in the report.
• List and briefly discuss the instrumentation required to monitor the velocity of the vehicle.
• The Nyquist Plot of the controller-based system, commenting on the stability of the system given the Gain and Phase margin produced.

Marks awarded for:

• Identifying the correct values of the overshoot, settling time and steady state error of the Open Loop response of the vehicle before the implementation of a suitable controller, with these values indicated on the Step Response graph. (20%)
• A suitable implementation of a P, PI or PID Controller, critically analysing their suitability for the given characteristic requirements, commenting on the step response of the system once the controller has been implemented. (40%)
• Suitable instrumentation panels implemented in the Simulink diagram (10%)
• Suitable description of sensors expected to be found in the aircraft to enable this system to work in real-time (10%)
• Suitable comments on the stability of the new system, using values obtained from a new Nyquist Plot. (20%)