By: Mark Bright and Mike Donaldson Advisor: Dr. Gary Dempsey

 Project Goal  System Applications  Thermal Plant Overview  Engine Side  Thermal Side

The goal of our Engine Control Workstation is to simulate thermal environments that are found in liquid-based cooling systems. With this system we created several different control methods via MATLAB and Simulink working together to control both the engine and thermal transient and steady state responses.

Car Application PC Application The overall goal of this project is to protect the motor with varying loads with minimum energy usage

Engine Side Circuitry Thermal Side Circuitry

Engine DSP Board Thermal DSP Board

Generator Thermistor Flowmeter Pump Pittman Motor Cooling Blocks

Thermal Comparison Pittman Motor  Tmax = 311 deg F  Thermal impedance 75.9 deg F/watt  (2.9 A)^2 * (3.91 ohm) = 36 watts  36W * (75.9 deg F/watt) = 2732 deg F

Engine Side Goals Engine Control:  Minimize C-code and execution time  Learn Auto-Code generation platform of Simulink/DSP interface  Design software for PWM generation and velocity calculation from rotary encoder.  Design closed-loop controllers for velocity and acceleration control.

 32 bit Processor  150 MHz Clock  16 A/D Channels  12 PWM Digital I/O Channels  128K on-chip Flash Memory  9 Ports Total  3.3v Supply  Interfaced to PC by serial port  Inputs and output go through level- shifter IC (5v to 3.3v / 3.3v to 5v)

User Interaction: Set RPM and Gain System DesignSimulink Model MATLAB GUI Code Composer Auto Code Generated C Code TI 2812 DSP Board PWM Output to Drive Motor

 Both encoder channels from the Pittman motor are offset from each other  Pulses are wired into the DSP board Port 8 – pins 6 and 7  2 counts can be obtained per period for each channel – 4 times as many counts  Allows for Steady State Error of ± 5 RPM  Simulink codes this as inner shaft RPM, which must be converted to outer shaft RPM – 5.9:1 gear ratio  Drag QEP Block into Simulink diagram to implement

 Data sent to GUI is set here  Model is used to generate Code Composer C code  P, PI, and FF Control Implemented

 Data sent to GUI is set here  Model is used to generate Code Composer C code  P, PI, and FF Control Implemented

 Data sent to GUI is set here  Model is used to generate Code Composer C code  P, PI, and FF Control Implemented

 Data sent to GUI is set here  Model is used to generate Code Composer C code  P, PI, and FF Control Implemented

 Data sent to GUI is set here  Model is used to generate Code Composer C code  P, PI, and FF Control Implemented

 Data sent to GUI is set here  Model is used to generate Code Composer C code  P, PI, and FF Control Implemented Desired RPM Actual RPM Controller Output PWM Duty Cycle

 Simulation model started where the 2008 mini project left off  Bilinear Transform converted analog controllers to digital controllers  P, PI, and FF Control Implemented

Gp = ______________ (s/146+1)(s/776+1) ______________ (s/146+1) (s/1460+1)17.1 FF=Gp = 17.1

Simulation:  596 RPM input  FF Output is 17 RPM  Impulse duration was 2mS Actual:  596 RPM input  FF Output is 17 RPM  As expected from simulation

 100 RPM Step Input  FF Control decreases response time by 20 mS  Less overshoot  Smaller time to first peak FF Compensation PI Control Only RPM vs Time (ms) plot

 Start, Type “guide” in MATLAB  GUI can be designed here with many components  Once designed, MATLAB creates an.m file and.fig file MATLAB GUI Design

 GUI created in MATLAB and interfaced to Simulink Model  Plots Motor RPM, PWM Duty Cycle, Transient Response, and both PI and Feed Forward Controller Output  User can input desired RPM: 0 to 834 RPM  Optimal controller gains loaded at startup, but user can control both the gain and type of control  GUI updates in real time

numMsgsOchan1 = r.msgcount('ochan1'); if (numMsgsOchan1) speed = r.readmsg('ochan1', 'int32'); end numMsgsOchan2 = r.msgcount('ochan2'); if (numMsgsOchan2) pid = r.readmsg('ochan2', 'int32'); end numMsgsOchan3 = r.msgcount('ochan3'); if (numMsgsOchan3) RPM = r.readmsg('ochan3', 'int32'); end numMsgsOchan4 = r.msgcount('ochan4'); if (numMsgsOchan4) PI_Out = r.readmsg('ochan4', 'int32'); end numMsgsOchan5 = r.msgcount('ochan5'); if (numMsgsOchan5) FFOut = r.readmsg('ochan5', 'int32'); end

if ((numMsgsOchan1 ~=0) && (numMsgsOchan2 ~= 0) && (numMsgsOchan3 ~= 0) && (numMsgsOchan4 ~= 0) && (numMsgsOchan5 ~= 0)) axes(handles.axes3); plot(handles.axes3,x_axis1, RPM); title(handles.axes3,'Measured speed of the Motor'); xlabel(handles.axes3,'t (s)'); ylabel(handles.axes3,'Speed (RPM)'); grid(handles.axes3,'on'); axis(handles.axes3,[ ]); axes(handles.axes4); cycle = double(pid); plot(handles.axes4,x_axis1, cycle); title(handles.axes4,'Duty Cycle of the PWM Waveform'); xlabel(handles.axes4,'t (s)'); ylabel(handles.axes4,'Duty Cycle (%) '); grid(handles.axes4,'on'); axis(handles.axes4,[ ]);

 Acceleration Control ◦ Adjustable Feed Forward control with different types of input commands: combos of ramps, steps, and parabolic. Load changes can simulate hills and different road conditions.  CAN Bus Interface ◦ Use the DSP board’s CAN bus to send data between the boards. This would allow for a main GUI to control both sides of the system.  Data Logging Feature ◦ Allow for a user to tune controllers and compare results. Could implement a new EE431 / 432 homework or design project around the system.  Set Control Points for Thermal and Engine Response ◦ Set desired temperature for a change in the coolant as well as a engine RPM governor based on load conditions

Hardware Interfacing

 Variable Resistance  Anti-aliasing filter

 Use PWM to drive Pump/Fan  Interface from digital to analog  Average Voltage seen by the device

 Opto-Isolator  TIP120 choice  Design for 3A Opto-Isolator

 LPF to ‘DC’ the PWM  Ideal Op Amp theory  Input = Pump Opto-Isolator

DSP/Simulink Data-Logging

 Conversion of A/D Value to Temperature  Excel Trendline Simulink Data-Logging

 Conversion of A/D Value to Temperature  Excel Trendline Simulink Data-Logging

 Conversion of A/D Value to Temperature  Excel Trendline Simulink Data-Logging

 Conversion of A/D Value to Temperature  Excel Trendline Simulink Data-Logging

Simulink Data-Logging cont.  Datatype conversions  Function auto-code generated

Simulink Data-Logging cont.  Datatype conversions  Function auto-code generated

Logging The Data

Model vs. Actual

Final Simulink Model

Thermal Model

Noise Addition

Anti-Aliasing Hardware

Software Conversion

Energy Management

Power Consumption

Heat Addition

Final Simulink Auto-Code Block

Controller Types  Bang – Bang  Improved Bang Bang  P Control  PI Control

Bang – Bang Control 300 Watts/ Min

Improved Bang-Bang Control 211 Watts / Min

P Control 62 Watts / Min

PI Control 143 Watts / Min

Thermal Efficiency (Degrees F/Watts) Pump PWM% Fan PWM%

Further Thermal Development  Supervisory Control  Further improvement by utilizing Pump and Fan cooling efficiencies  Faster PID Control  Use of more temperature sensors  Use of CAN bus

 Nick Schmidt ◦ Case Assembly ◦ Hardware Assembly  Dr. Dempsey ◦ Case Assembly ◦ Hardware Assembly

P Control – Crossover Freq  Plant Wc is at 899 rad/sec  P Control System Wc was at 164 rad/sec  Gain =.08  Phase Margin with P control: ◦ 115 Gp = __________________ (s/146+1)(s/776+1) 17.1

 Gp(s) =K * 1/(Tc(s)+1) * e^-(s)Td  Pump/Plant ◦ K = (-.8 degrees F / 6.4 V) ◦ Tc = 20 ◦ Td = 6  Fan/Plant ◦ K = (-9.6 degrees F / 13V) ◦ Tc = 12 ◦ Td = 15

 P-Pump ◦ Wc =.148 radians PM = 105 GM =22.1dB  P-Fan ◦ Wc = ? PM = undefined GM =29.4dB  PI-Pump ◦ Wc =.39 radians PM = -139 GM =16.1dB  P-Pump ◦ Wc =.0966 radians PM = -48 GM =-15.92dB

Reading the data  OCHAN’s allow for data to be outputted to: ◦ GUI ◦ Workspace

H-Bridge Servo Amplifier  PWM Brush Type Servo Amplifer – Model 10A8DD  Protected for over- voltage and over- current  DC Supply Voltage: v  Peak Current: ±10A  Maximum Continuous Current: ±6A

Active Load

Conversions (A/D to Temp, PWM% to Watts

Energy Management

Heat Addition

Power

Thermal

Noise

Software Conversion

Opto-Isolator 4N25

LMC6482 Op-Amp

TIP 120 Power Amp

MC Volt regulator

SN74.. Level-shifter

Flowmeter Graph