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Idle speed

About: Idle speed is a research topic. Over the lifetime, 2012 publications have been published within this topic receiving 14108 citations.


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Patent
06 Feb 1995
TL;DR: In this paper, a driver-operated gear ratio selector lever is used to adjust the level of the driver-selected clutch actuation in response to an engine speed error signal (E) derived from a comparison of current engine speed and a reference speed signal (Vr) generated by the control unit.
Abstract: A clutch control system for the automatic control of a motor vehicle clutch (14) which connects an engine (10) with a gearbox (12) under the control of a driver-operated gear ratio selector lever (24). The control system including an electronic control unit (36) which controls initial clutch take-up on starting of the vehicle, clutch re-engagement following each ratio change, disengagement on movement of the gear selector lever to change the operative ratio of the gearbox, and clutch disengagement on the coming to rest of the vehicle. The level of clutch engagement is controlled in response to an engine speed error signal (E) derived from a comparison of current engine speed (Ve) and a reference speed signal (Vr) generated by the control unit, the error signal being compared with a current clutch position signal (Vc) to produce a clutch actuation signal (Vce). The reference signal for initial clutch take-up is derived from one of the following references on a highest-wins basis: a reference signal proportional to the current throttle position (Va'), a reference signal proportional to the current engine idle speed (Vir), or a floating reference signal (Vfr) equal to a recorded engine speed plus an offset.

219 citations

Proceedings ArticleDOI
22 May 1989
TL;DR: In this paper, an electric direct-drive gearless starter-generator was designed and built for an aircraft engine application, based on a switched-reluctance motor, which was chosen for its simplicity, robustness, high speed capability, and efficiency.
Abstract: An electric direct-drive gearless starter-generator has been designed and built for an aircraft engine application. The system is based on a switched-reluctance motor, which was chosen for its simplicity, robustness, high-speed capability, and efficiency. The overall system configuration and the design of the switched-reluctance motor and its solid-state power converter are described. When operating as engine starter, the motor produces torque to spin the engine up to its light-off speed. Following light-off, the motor continues to produce torque to assist the engine in accelerating to idle speed. When the engine is running, the machine generates electrical power to supply engine and vehicle loads up to a peak operating speed of 50000 r/min. Key issues in the machine design are reliability, high speed, power density, and cost. Test results have verified that the system can meet the torque and generated-power requirements over its entire operating range. >

154 citations

Patent
14 May 2004
TL;DR: In this paper, a diesel compression engine and an electric machine are coupled to rotate the engine during cold engine cranking in a staged manner, including a first stage where the engine is cranked to a first speed below the resonant speed of the coupled engine and electric machine combination for a first duration and thereafter cranked up to a second speed above the resonance speed for a second duration.
Abstract: A powertrain includes a diesel compression engine and an electric machine operatively coupled thereto and effective to rotate the engine during engine cranking. Cold engine cranking is accomplished in a staged manner including a first stage wherein the engine is cranked to a first speed below the resonant speed of the coupled engine and electric machine combination for a first duration and thereafter cranked to a second speed above the resonant speed for a second duration. Transition out of cranking at the first and second speeds is accomplished when relative combustion stability is demonstrated. Cranking at the first or second speed is aborted when excessive crank times or if low battery voltages are observed. A third stage is included wherein the engine is cranked to a third speed below the engine idle speed. Transition out of cranking at the third speed is accomplished when relative combustion stability is demonstrated, whereafter normal engine control takes over.

153 citations

Journal ArticleDOI
TL;DR: A model predictive control strategy for regulating the engine speed to the idle speed set-point by actuating the electronic throttle and the spark timing and an MPC controller is developed that performs better than an existing baseline controller in the vehicle, is robust to changes in operating conditions, and to different types of disturbances.
Abstract: Idle speed control is a landmark application of feedback control in automotive vehicles that continues to be of significant interest to automotive industry practitioners, since improved idle performance and robustness translate into better fuel economy, emissions and drivability. In this paper, we develop a model predictive control (MPC) strategy for regulating the engine speed to the idle speed set-point by actuating the electronic throttle and the spark timing. The MPC controller coordinates the two actuators according to a specified cost function, while explicitly taking into account constraints on the control and requirements on the acceptable engine speed range, e.g., to avoid engine stalls. Following a process proposed here for the implementation of MPC in automotive applications, an MPC controller is obtained with excellent performance and robustness as demonstrated in actual vehicle tests. In particular, the MPC controller performs better than an existing baseline controller in the vehicle, is robust to changes in operating conditions, and to different types of disturbances. It is also shown that the MPC computational complexity is well within the capability of production electronic control unit and that the improved performance achieved by the MPC controller can translate into fuel economy improvements.

138 citations

Patent
29 Apr 1996
TL;DR: In this paper, a fluid operated clutch is incorporated between the engine and the gearing so that the motor/generators can drive the PTO shafts independently of the engine, and the main pump fluid output can be directed to engage the clutch when the engine input is desired.
Abstract: A power transmission has an internal combustion engine and motor/generators which are combined through a summing planetary gearing. The planetary gearing cooperates with downstream gearing to provide a hybrid power transmission. A plurality of auxiliary or power take-off (PTO) shafts are included to permit the operation of auxiliary devices, such as main hydraulic pumps, air conditioners or power steering pumps. A fluid operated clutch is incorporated between the engine and the gearing so that the motor/generators can drive the PTO shafts independently of the engine. The main pump fluid output can be directed to engage the clutch when the engine input is desired. The motor/generators are controlled to provide output speed resulting in one member of the gearing being driven at a speed equal to the idle speed of the engine, such that the clutch can be synchronously engaged.

135 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202114
202049
201953
201856
201753
201659