Active Suspension System. Josh Rose, Xander Serrurier, Rhydon Vassay, Chase Ramseyer Advisor: Steven Gutschlag 4/27/2017

Transcription

1 Active Suspension System Josh Rose, Xander Serrurier, Rhydon Vassay, Chase Ramseyer Advisor: Steven Gutschlag 4/27/2017

2 Outline 1. Project Summary 2. Previous Work 3. Functional Description 4. System Block Diagram 5. Work Completed/Results 6. Future Work 7. Questions 2

3 Project Summary Suspension Systems Purpose Used to support the chassis of a vehicle on its axles Used to prevent chassis movements caused by road imperfections to the car s passengers Primary types Passive Active Hybrid (semi-active) 3

4 Project Summary Suspension Systems Suspension system type Passive suspension system Semi-active suspension system Active suspension system Regulatory element General shock absorber Adjustable damping Hydraulic system or Servo motor system Action principle Damping constant Damping continuously adjustable Adjust the force between wheel and vehicle body Control method No Hydraulic Electronics or fluid control Bandwidth Unknown Up to 20Hz > 15Hz Energy consumption Zero Minimal Significant Lateral dynamics control Poor Moderate Good Vertical dynamics control Poor Moderate Good Cost Lowest Middle Highest 4

5 Project Summary Objectives Redesign existing active suspension system Design/implement safety measures Design power electronics to operate existing hardware Develop rudimentary control software 5

6 Project Summary ACTSS Overview Real-time disturbance minimization Applications Cars, tractors, off-road vehicles Chassis suspension Cab/seat suspension 6

7 Project Summary Previous Work Developed power electronics H-bridge Snubber circuits Isolation circuits Developed proportional control system Disturbance cancelled: 75% with load 87.5% without load 7

8 Previous Work Hardware Specifications EMAC Micropac MHz on-board crystal Separate LCD/keypad interfaces 8 10-bit ADC channels 24 digital IO 3 EIA-232 serial ports Programmed in Assembly 8

9 Previous Work Hardware Specifications MSK4227 H-Bridge 200V, 20A rating (Tc = 25 C) 20µA logic input current 1µs minimum switching dead time required Direct-mounted heatsink with forced convection 9

10 Previous Work Hardware Specifications 4N25 Optical Isolator 5V supply voltage 10mA enable current Max 70V output 50mA output current 2µs switching speed 5000V isolation voltage 10

11 Previous Work Hardware Specifications IDC EC2-H Electric Cylinder 160V DC, 12A 3600N max thrust 930mm/sec max no load speed 1 in/ 27.2ms 5.0N-m max torque 11

12 Previous Work Hardware Specifications Position Sensors (P1613) Light duty potentiometer 2 in bidirectional travel 2K Ohms 3-Phase Motor (4Z394) Camshaft (VPLE-212) 1in displacement 12

13 Current Hardware List Atmel ATmega 128 Microcontroller Personal extensive experience Code development in embedded C 6MHz on-board crystal 8 10-bit ADC channels 53 digital IO channels 2 serial ports 13

14 Current Hardware List 6N137 Optical Isolator 5V supply voltage 15mA enable current Logic-level output 50mA output current 10Mega-Baud switching speed 5300V isolation voltage 14

15 Functional Description System Overview 15

16 System Block Diagrams Subsystem Overview PWM Actuator PWM Motor Upper Position Sensor Linear Actuator Power Electronics Lower Position Sensor Microcontroller ADC Keypad LCD Em_Stop Upper Platform 16

17 System Block Diagrams Conceptual Flow Chart 17

18 System Block Diagrams H-Bridge Overview NC NC V+ V+ B0 +VCC B0 +VB A0 HINA A0 LINA BV- HINB BV- LINB AV- COM AV- COM 18

19 Work Completed/Results H-Bridge Isolation 19

20 Work Completed/Results H-Bridge With Isolation HINA LINA Gate Drive Circuit LINB HINB 20

21 Work Completed/Results H-Bridge Testing H-bridge output (e.g. A0) Optical Isolator output Switching Signal (From Function Generator) 21

22 Work Completed/Results Testing the Potentiometer 22

23 Work Completed/Results Voltage Regulator Circuits 23

24 Work Completed/Results Snubber Circuit 24

25 Work Completed/Results PSpice Simulations 25

26 Work Completed/Results PSpice Simulations Load Current 26

27 Work Completed/Results PSpice Simulations Load Voltage 27

28 Work Completed/Results Software PWM creation Timer/count match interrupt Feedback ADC interrupt User interface Keypad LCD External interrupts 28

29 Software PWM Creation Timer/counter 1 Fast PWM mode Output compare OCCR1A OCCR1B 29

30 Software Feedback (ADC) ADC interrupt Indicates conversion complete Calculation Input from potentiometer Determines position based on voltage 30

31 Software User Interface Run with control system Run without control system Manually extend/retract actuator 31

32 Results Simulations 32

33 Results Simulations 33

34 Results Safety Design Physical isolation Reduced reaction time Heat dissipation Emergency control Limit switches Emergency stop 34

35 Results Safety Design 35

36 Parts List Part Description Quantity Cost ($) Supplier Purchased Microcontroller and Development Board Waveshare Y Keypad Vetco Y LCD Display Ebay Y Atmega128 Programmer Mouser Y MSK4227 H-Bridge 1 Unavailable MSK N PS21A79 Replacement H-Bridge Digikey Y 6N137 Optical Isolator Mouser N IDC Electric Cylinder EC2H Linear Actuator Amazon N Maurey Linear Motion Sensor P1613 Position Sensor Process Industrial Surplus Corp N Maxi-Torq 4z394 3-Phase Motor Amazon N Camshaft Motion Industries N Atmega128A Dev Kit Keypad LCD (HD44780) AVR Dragon VPLE

37 Parts List Part Description Quantity Cost ($) Supplier Purchased ADXL335 Accelerometer Digikey Y Emergency Stop Newark Y HEV2AN-P-DC24V Power Relay Newark Y MY4N-D2-DC24 4 Pole Relay Digikey N Enclosure Amazon Y LM317 Voltage Regulator Digikey N 7805 Voltage Regulator Digikey N 7815 Voltage Regulator Digikey N Cooling Fan Digikey N NBF EE80251S2-000U-999 Total Cost $

38 Division of Labor Task Worked on by Completed Research All Yes Software Development Xander, Chase Yes Test Actuator Rhydon, Josh Yes Test H-Bridge All Yes Test Position Sensors Josh, Rhydon Yes Snubber Circuit Design Rhydon, Josh Yes PSpice Simulations Josh Yes Develop Rudimentary Control System Xander, Chase Testing Safety Design Chase, Josh Yes Assemble System All Yes Run Test Cases on System All Testing Documentation All Yes 38

39 Future Work Design/mount additional physical safety measures Front shield Top shield Develop a more complex position-based control scheme Design and implement an acceleration-based control system using an accelerometer 39

40 References Previous Senior Projects: Patrice Jackson and Shawn Downey (2003) Blake Boe and Tyson Richards (2006) Research Papers [1] W.K.N. Anakwa. Development and Control of a Prototype Pneumatic Active Suspension System. Bradley University, IL, Oct [2] Q. Zhou. Research and Simulation on New Active Suspension Control System. Lehigh University, PA,

41 Questions?

42 Regulator Power Calculations P12V = 2.328W P15V = 0.030W P5V = 0.114W TJ = PRJA + TA T12V =

43 Actuator Motion 43