E- 579Mechatronics Modeling and SimulationTerm Project - “ Steer By Wire”InstructorDr. Shuvra Das Divesh Mittal
Contents • Introduction • System level modeling • Bond graph model • SBW control • Results and Discussion • Limitations and Future work • References E-579 - Steer By Wire system
Introduction and Significance • By wire system is getting popular because of its efficient and accurate operations. • There are still few concerns and issues. • Idea here is to model simple steer by wire system and see if we can replicate the results from existing hydraulic steering system. • This is simple model to understand, idea needs to be extended in order to get more close to real world. E-579 - Steer By Wire system
Problem Definition • Understand and prepare system level model of Steer By Wire (SBW) system. • Making the suitable assumptions to break down whole system into simple energy storage or dissipating elements. • Convert above information into bond graph model and simulate it on 20-SimTM. • Plot wheel angle and validate it with similar results from other references. E-579 - Steer By Wire system
Steer By Wire System [“Embedded Steer-by-Wire System Development”, Embedded World, 17-19 February 2004, Nuremberg, Germany] E-579 - Steer By Wire system
Steer by Wire Reference: http://www.Howstuffworks.com E-579 - Steer By Wire system
Introduction • System level modeling • Bond graph model • SBW control • Results and Discussion • Limitations and Future work • References E-579 - Steer By Wire system
Steering Wheel Motor Steering Actuator (Motor) System Level Model SBW Controller Subsystem Front Wheel Subsystem Steering Wheel Subsystem • Control Unit • Reactive torque • Control Path Torque Sensor Rack / Pinion Gear Steering Angle Sensor Tie rod Tire-Wheel subsystem Steering Column E-579 - Steer By Wire system
Modeling of SBW • SBW system is composed of steering subsystem, controller and tire subsystem. • Model subsystems with the help of major components. • Each component is a combination of capacitive/inertia/resistor elements and is connected to other components with either a transformer / gyrator elements or series / parallel junction. E-579 - Steer By Wire system
Block Diagram Torque Input Control Unit DC Motor Rack /pinion gear Tire/wheel assembly E-579 - Steer By Wire system
Introduction • System level modeling • Bond graph model • SBW control • Results and Discussion • Limitations and Future work • References E-579 - Steer By Wire system
Manual Rack and pinion steering system Steering wheel/ column Rack and pinion / tire assembly E-579 - Steer By Wire system
Without feedback/No control Front wheel actuator motor Rack/Pinion, tie rod and tire asembly Steering wheel E-579 - Steer By Wire system
Data[3] E-579 - Steer By Wire system
Front wheel angle E-579 - Steer By Wire system
Validation Result from reference [1] E-579 - Steer By Wire system
Front wheel angle Vs steering wheel angle 1.70 400 E-579 - Steer By Wire system
Steering subsystem E-579 - Steer By Wire system
Introduction • System level modeling • Bond graph model • SBW control • Results and Discussion • Limitations and Future work • References E-579 - Steer By Wire system
SBW Controller • Steering wheel Motor Controller • Front wheel actuator motor controller E-579 - Steer By Wire system
Controller SBW controller [3] E-579 - Steer By Wire system
Steering Motor Controller • Generates reactive torque. • Easy to drive at low speed and vice versa. • Reactive torque is function of velocity E-579 - Steer By Wire system
Gain factor for Steering control Gain for steering motor actuator [3] E-579 - Steer By Wire system
Feed forward control Bicycle model for steering behavior [3] E-579 - Steer By Wire system
Steering Torque Controller E-579 - Steer By Wire system
Reaction Torque Control E-579 - Steer By Wire system
Introduction • System level modeling • Bond graph model • SBW control • Results and Discussion • Limitations and Future work • References E-579 - Steer By Wire system
Results • Steer by wire was modeled using bond graph technology. • Controller for SBW improves maneuverability and handling. • Reactive torque can be controlled using torque control mechanism. E-579 - Steer By Wire system
Proposed Time line VS Achievement Mapping E-579 - Steer By Wire system
Introduction • System level modeling • Bond graph model • SBW control • Results and Discussion • Limitations and Future work • References E-579 - Steer By Wire system
Limitations and Future Work • Torque control mapping for steering motor. • Front wheel motor voltage control. • Importing Matlab file for lookup tables. E-579 - Steer By Wire system
References • Srihari Vijaykumar ,”Analysis of an electric power assisted steering system using bond graphs”, SAE paper 2003-01-0586. • Srihari Vijaykumar ,” Application of bond graph technique to the design of passenger car steering system”, SAE paper 2002-01-0617. • Se-Wook Oh,” The development of an advanced control method for the steer-by-wire system to improve the vehicle maneuverability and stability”, SAE paper 2003-01-0578 E-579 - Steer By Wire system
Questions ?? E-579 - Steer By Wire system
