Electronic throttle control
- Electronic throttle control
Electronic throttle control (ETC) is an automobile technology which severs the mechanical link between the accelerator pedal and the throttle. Most automobiles already use a throttle position sensor (TPS) to provide input to traction control, antilock brakes, fuel injection, and other systems, but use a bowden cable to directly connect the pedal with the throttle. An ETC-equipped vehicle has no such cable. Instead, the electronic control unit (ECU) determines the required throttle position by calculations from data measured by other sensors such as an accelerator pedal position sensor, engine speed sensor, vehicle speed sensor etc. The electric motor within the ETC is then driven to the required position via a closed-loop control algorithm within the ECU.
The benefits of ETC are largely unnoticed by most drivers because the aim is to make the vehicle power-train characteristics seamlessly consistent irrespective of prevailing conditions, such as engine temperature, altitude, accessory loads etc. The ETC is also working 'behind the scenes' to dramatically improve the ease with which the driver can execute gear changes and deal with the dramatic torque changes associated with rapid accelerations and decelerations.
Contrary to popular beliefFact|date=June 2008, except in concert with other technologies such as gasoline direct injection, ETC provides only a very limited benefit in areas such as air-fuel ratio control, exhaust emissions and fuel consumption reduction. ETC however makes it much easier to integrate features to the vehicle such as cruise control, traction control, stability control and others that require torque management, since the throttle can be moved irrespective of the position of the driver's accelerator pedal. A criticism of the very early ETC implementations was that they were "overruling" driver decisions. Nowadays, the vast majority of drivers have no idea how much intervention is happening.
Much of the engineering involved with drive-by-wire technologies including ETC deals with failure and fault management. Most ETC systems have sensor and controller redundancy, even as complex as independent microprocessors with independently written software within a control module whose calculations are compared to check for possible errors and faults.
Anti-lock braking (ABS) is a similar safety critical technology, whilst not completely 'by-wire', it has the ability to electronically intervene contrary to the driver's demand. Such technology has recently been extended to other vehicle systems to include features like brake assist and electronic steering control, but these systems are much less common, also requiring careful design to ensure appropriate back-up and fail-safe modes.
See also
* Drive-by-wire
* Brake-by-wire
Wikimedia Foundation.
2010.
Look at other dictionaries:
Electronic stability control — (ESC) is a computerized technology [1][2] that may potentially improve the safety of a vehicle s stability by detecting and minimizing skids.[3] When ESC detects loss of steering control, it automatically applies the brakes to help steer the… … Wikipedia
Electronic speed control — An electronic speed control or ESC is a device mounted onboard an electrically powered radio control model in order to vary its drive motor s speed, its direction and even to act as a dynamic brake in certain controllers.An ESC can be a stand… … Wikipedia
electronic engine control — An electronic fuel control for gas turbine engines. It sends out metered fuel to the engine for all flight conditions by sensing various parameters, such as the throttle position, engine RPM, atmospheric conditions, speed, and height. EEC… … Aviation dictionary
electronic air control valve — (EACV) A valve used in fuel injection system, usually computer controlled, that controls the amount of air bypassing the throttle during idle. The more air that bypasses the throttle, the higher the idle speed … Dictionary of automotive terms
Throttle — A throttle is the mechanism by which the flow of a fluid is managed by constriction or obstruction. An engine s power can be increased or decreased by the restriction of inlet gases ( i.e., by the use of a throttle). The term throttle has come to … Wikipedia
Throttle body — In a fuel injection engine, the throttle body is the part of the air intake system that controls the amount of air flowing into the engine, in response to driver input. While the accelerator is often called a gas pedal , it would be more accurate … Wikipedia
Electronic instrument cluster — Digital dash redirects here. For the business tool, see Dashboard (disambiguation). In an automobile, an electronic instrument cluster, digital instrument panel or digital dash for short, is a set of instrumentation, including the speedometer,… … Wikipedia
Cruise control — For the software build framework, see CruiseControl. Cruise control mounted on a 2000 Jeep Grand Cherokee Steering Wheel Cruise control (sometimes known as speed control or autocruise) is a system that automatically controls the speed of a motor… … Wikipedia
Mobile Electronic Certified Professional — Mobile Electronics Certified Professional or MECP is a certification program for installation technicians of mobile electronics and aftermarket automotive equipment. Overview MECP is the only nationally recognized program that certifies mobile… … Wikipedia
throttle position sensor — (TPS) A potentiometric fuel injection switch with two contacts for the two end positions of the throttle valve, which sends a signal to the electronic control unit when the throttle valve is closed (idle) or wide open (full load). The sensor… … Dictionary of automotive terms
