21-02-2012, 12:21 PM
DRIVE-BY WIRE SYSTEMS
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Introduction and Background
For the past 25 years, by-wire systems have been used in the most advanced Flying machines known to man. Fly-by-wire is where each mechanism is controlled electronically. The mechanical linkages are removed and every movement is communicated through electric signals alone. The use of electronic motors to control movement has proven to be more responsive and a more efficient use of space and energy. Thus the by-wire control is now setting the stage for better, faster vehicles in the air and on land.
The Brakes-By-Wire
In future automobiles will serve as the vehicle for high speed applications. Therefore it was very important to make a vehicle that has a reliable and effective brake. As discussed in the background chapter, there are two ways that brakes can be electronically controlled: electrohydraulic braking and electromechanical braking. First, the car must be capable of being manually operated. So, one guideline was to make sure the hardware installed in the car does not interfere with the driver’s space. Secondly, the hardware must be installed in such a way that a person can drive the vehicle without having to move any components of the by-wire system. Thirdly, the by-wire system must be robust and durable. Actuators should not interfere with the driver’s space on the floor. In addition, since the actuator is mounted inside the vehicle, the actuator is protected from the elements.
Control of the Brakes System
This section will explain how the brake is controlled:-
a) The control architecture will be explained.
b) An overview of the software programs used will be presented.
c) All other control considerations such as calibration of the motor and motor feedback will be discussed.
The Steer-By-Wire
This section will focus on describing the steer-by-wire system in the drive by system. First recruitment of the steer-by-wire system must be reliable and responsive. The car Controller must consistently demonstrate complete control of the steering system. Also, a responsive vehicle will be able to change directions on Command. If the car is not responsive to controller inputs, vehicle control will be compromised and is not safe. The vehicle must also be accurately controlled Accuracy is a necessity especially for high speed applications and the heading of the vehicle must be reliable and accurate. Furthermore, accurate steering control will help ensure that the vehicle is safe.