12-01-2011, 12:06 AM
STABILITY OF VEHICLE BY ACTIVE GEOMETRICALLY CONTROL SUSPENSION
PRESENTED BY
NIJU K.PONNAPPAN
PRESENTED BY
NIJU K.PONNAPPAN
ENHANCEMENT OF VEHICLE STABILITY BY ACTIVE GEOMETRY.ppt (Size: 426.5 KB / Downloads: 142)
seminar paper:
http://www.mediafire?753pvj5vo8hzeq6
INTRODUCTION
NEED OF HIGH PERFORMANCE SUSPENSION
CONVENTIONAL SUSPENSION SYSTEMS
SLOW ACTIVE SUSPENSION SYSTEM
4 WS
AGCS OVERVIEW
The kinematics arrangement suspension link changes toe angle, which of the is largely affecting running stability, as the running condition changes.
AGCS system is a device to optimise the toe-in value
AGCS system consist of actuator, control lever (these are mounted on rear suspension) and an ECU.
The sensory part consist of a speed sensor,steering angle sensor and steering rate sensor.
The ECU varies the actuator stroke according to the feed back.
This produces an optimum Toe-in value of rear outside wheel.
COMPARISON
CONTROL LOGIC
The objective was to maximise the positive effect of AGCS
The important aim to accomplish are:
To get a consistant handling characteristics at all speed.
Definition of different control maps with increasing AGCS application strokes with increasing lateral acceleration levels for better progressivity and natural effect on the handling response of the vehicle.
SIMULATION AND TEST RESULTS
Done using ADAMS full mode vehicle.
Step sheer input simulation
Vehicle speed 140 kmph
Steering wheel angle 50 degree
SINUSOIDAL INPUT SIMULATION
Vehicle speed 140kmph
CONCLUSIONS
(1) The AGCS system is applied on the rear suspension to regulate bump toe-in using the electric actuator which varies the geometry of assist link, and enables to improve road grip and extend the slipping point.
(2) Because the control direction is perpendicular to the acting load in regulating wheel toe-in, the system is inherently more efficient than conventional systems that control in the same direction as the acting load.
(3) AGCS system has superior handling performance when compared to the conventional system in step input simulation results and subjective tests.
REFERENCES
Català, A. (2004). Dry Handling Tuning of AGCS Systems with IDIADA Technical Reports SC 050507-1. Spain.
Lee, U. K. (1994). Suspension System for Vehicle. Patent No. U.S. 5,577,771. USA.
Lee, U. K. (1996). Vehicle Suspension System for a Steerable Wheel. Patent No. U.S. 5,700,025. USA.
Mechanical dynamic Inc(2002) ADAMS car users guide.
AUTO CAR INDIA September edition 2005
International automobile journal.
www.wikipedia.com