Transcript Design and Prototype Build of the Interfaces of a Steer

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 SubSystem
Microcontroller SubSystem
Rack-and-Pinion SubSystem
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 Process


Functional Decomposition
Function Concept-Mapping
Evaluation Process




Feasibility Testing
Go/No-Go Screening
Decision Matrices
Failure Mode Effects Analysis (FMEA)
Final Concept

Motor to Rack-and-Pinion Interface


Motor to Motor Interface


Stackable Sensors / Shaft
Sensor to Rack and Pinion Interface


Gear Train
Sensor to Sensor Interface


Gear Train
Direct Shaft
Motor
Controllers
Metal Stand
Position
Sensors
Motor
Motor
Stacked /
Shaft
Rack
Gear Train
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 Requirements
Max deflection of 12.7mm
Max stress of 450MPa
Stand Analysis Results
Max 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
Sensors
Hollow-angle sensors


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

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.