Dynamic braking

About: Dynamic braking is a research topic. Over the lifetime, 3472 publications have been published within this topic receiving 34897 citations. The topic is also known as: Rheostatic brake.

Improvement of drivability and fuel economy with a hybrid antiskid braking system in hybrid electric vehicles

Abstract: When braking on wet roads, Antilock Braking System (ABS) control can be triggered because the available brake torque is not sufficient. When the ABS system is active, for a hybrid electric vehicle, the regenerative brake is switched off to safeguard the normal ABS function. When the ABS control is terminated, it would be favorable to reactivate the regenerative brake. However, recurring cycles from ABS to motor regenerative braking could occur. This condition is felt to be unpleasant by the driver and has adverse effects on driving stability. In this paper, a novel hybrid antiskid braking system using fuzzy logic is proposed for a hybrid electric vehicle that has a regenerative braking system operatively connected to an electric traction motor and a separate hydraulic braking system. This control strategy and the method for coordination between regenerative and hydraulic braking are developed. The motor regenerative braking controller is designed. Control of regenerative and hydraulic braking force distribution is investigated. The simulation and experimental results show that vehicle braking performance and fuel economy can be improved and the proposed control strategy and method are effective and robust.

Braking device for elevator winding machine and elevator using the braking device

Abstract: A braking device for an elevator winding machine generates a braking force by contacting a rotary body driven by a rotary shaft of the winding machine with a brake section supported through the intermediary of an elastic body. The elastic body has a nonlinear elastic characteristic so that a starting shock to the passengers in the elevator car is prevented and the braking torque detecting accuracy is improved.

Steering drift and wheel movement during braking: Static and dynamic measurements:

Abstract: This paper reports on an experimental investigation into braking-related steering drift in motor vehicles, and follows on from a previous paper by the authors in which it was concluded that braking can cause changes in wheel alignment that in turn affect the toe-steer characteristics of each wheel and therefore the straight-line stability of the vehicle during braking. Changes in suspension geometry during braking, their magnitude and the relationships between the braking forces and the suspension geometry and compliance are further investigated in an experimental study of wheel movement arising from compliance in the front suspension and the steering system of a passenger car during braking. Using a kinematic and compliance (K&C) test rig, movement of the front wheels and the suspension subframe, together with corresponding changes in suspension and steering geometry under simulated braking conditions, have been measured and compared with dynamic measurements of the centre points of the front whe...

Process and arrangement for constant speedkeeping through actuation of a motor vehicle's braking system

Abstract: The invention relates to a process and arrangement designed, through braking, to keep constant the speed of a motor-vehicle when travelling on downhill slopes. With the aim of producing simple actuation and deactuation of the constant speedkeeping function, the invention is characterized principally in that the constant speedkeeping function commences upon actuation of a driver-activated brake control (17). In connection with this, the lowest vehicle speed is stored as a target value within the memory of a control unit (1). The actual vehicle speed is then regulated towards the target value through activation of the vehicle brakes (4). Only once an ordinary driver-activated control (19) is activated, is the specified regulation towards the target value suspended.

Multiple-Railcar High-Speed Train Subject to Braking

Abstract: The dynamic response of a high-speed multiple-railcar train experiencing deceleration under braking condition over a straight track is investigated using the moving element method. Possible sliding of train wheels over the rails is accounted for. The train is assumed to comprise a locomotive as the leading railcar and several passenger railcars connected to each other through train couplers. Each railcar is modeled as a 15-DOF system of interconnected car body, two bogies and four wheels. The rail is modeled as an Euler–Bernoulli beam resting on a two-parameter elastic damped foundation. The train and rails are coupled through normal and tangential wheel–rail contact forces. The effects of various parameters, such as braking torque, coupler stiffness, coupler gap, wheel load, wheel–rail contact condition, initial train speed and partial failure in braking mechanism on the dynamic response of the train subject to braking are investigated. It is found that there is significant interaction between neighboring railcars when the braking torque is applied between the optimal and critical torques. The former is the torque that would result in the smallest braking distance with no occurrence of wheel sliding and the latter is the smallest torque to cause wheel sliding in all four wheels.