design and prototype build of the interfaces of a steer-by-wire assembly javier angulo alan...
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Design and Prototype Build of the Interfaces of a Steer-By-Wire Assembly
Javier Angulo
Alan Benedict, Team Leader
Amber Russell, Team Manager
Kurush Savabi
Dr. Sohel Anwar, Faculty Advisor & Sponsor
Dr. Hazim El-Mounayri, Course Instructor
Overview
• Purpose & Objective
• Requirements & Targets
• Concept Generation & Evaluation
• Product Generation & Evaluation
• Conclusions & Recommendations
Introduction
Overall Purpose:
Create a steer-by-wire system parallel to that of an automobile for use in laboratory
Introduction (continued)
Driver Interface Sub-System
Microcontroller Sub-System
Rack-and-Pinion Sub-System
Overall Steer-By-Wire System
Objectives of Design
Objectives: Design of an interface between a standard automotive
rack-and-pinion steering assembly and electric motors.
Design of an interface between the same rack-and-pinion steering assembly and angle position sensors
Design of a stand to support the entire system and provide reaction forces to rack
Requirements and Targets
Functionality and safety Benchmark Visteon-GM Sequel
Requirements and Targets (continued)
Concept Development & Evaluation
Development ProcessDevelopment Process Functional Decomposition Function Concept-Mapping
Evaluation ProcessEvaluation Process Feasibility Testing Go/No-Go Screening Decision Matrices Failure Mode Effects Analysis (FMEA)
Final Concept
Motor to Rack-and-Pinion Interface Gear Train
Motor to Motor Interface Gear Train
Sensor to Sensor Interface Stackable Sensors / Shaft
Sensor to Rack and Pinion Interface Direct Shaft
Metal Stand Position Sensors
Stacked / Shaft
Rack
Motor
Motor Controllers
Gear Train
Motor
Pinion 1 Pinion 2
Product Generation & Evaluation
Motors Requirements Torque of 52 Nm at 67 rpm Torque of 20.8 Nm at 133 rpm Input voltage of <60 VDC
Selected Motor Specifications Torque of 52 Nm at 67 rpm Torque of 20.8 Nm at 127.4 rpm Input voltage of 75 VDC
Product Generation & Evaluation
Motor Interfaces Enables redundancy Allows for maintenance
Product Generation & Evaluation
Stand RequirementsMax deflection of 12.7mm
Max stress of 450MPa
Stand Analysis ResultsMax deflection of 1.83E-4mm
Max stress of 89.1MPa (Dynamic)
FOS 3 to 5 (267.3MPa to 445.5MPa)
Product Generation & Evaluation
Springs Spring Requirements of 102 kN/m Selected Spring Specifications of 83 kN/m Force of 6876 N (to simulate dynamic loading)
Maximum Stress = 104.6 MPa Yield Strength of Plate = 250 MPa
Product Generation & Evaluation
SensorsHollow-angle sensors Ease of interface Zero backlash Lack of availability Lower accuracy Requires less space
Conventional Potentiometers Meet accuracy requirement Readily available Cost efficient Requires gear train interface (backlash)
Final Design
Final Design (continued)
Engineering Requirements
Questions
For further questions, please feel free to ask the design team or refer to the project report. Thank you.
References
Cesiel, Daugherty, Gaunt, “Development of a Steer-by-Wire System for the GM Sequel”, SAE Technical Paper Series, 2006-01-1173.
David G. Ullman, “The mechanical design process”, Third edition, McGrawHill, 2003, USA.
“Delphi Non-Contact Multi-Turn Rotary Position Sensor”, Delphi, www.delphi.com.
“Electric Power Assisted Steering”, Visteon, 2005.
Matweb, www.matweb.com. March 2007.
Miller, Duane K., P.E., Use “Undermatching Weld Metal Where Advantageous: Practical Ideas for the Design Professional”, Welding Innovation, Vol. XIV, No. 1, 1997.
Parker Motion, www.parkermotion.com. April 2007.
Roy Mech, www.roymech.co.uk/useful_tables/form/weld_strength
“Sensors for Position Measurement: Single-turn/Multi-turn Steering-angle Sensor”, Hella International, www.hella.com.