Analysis of Effect on Change Rate of Wheel Cylinder Pressure for Electro-Hydraulic Brake System of Electric Vehicle

2012 ◽  
Vol 209-211 ◽  
pp. 2094-2099
Author(s):  
Xiu Yuan Xing ◽  
Ze Chang Sun ◽  
Meng Wang
Keyword(s):  
Electric Vehicle ◽  
Pressure Change ◽  
Brake System ◽  
Impact Factors ◽  
Cylinder Pressure ◽  
Change Rate ◽  
Hydraulic Brake ◽  
Brake Pressure ◽  
New Type ◽  
The Impact

Based on a new type of electro-hydraulic brake system of electric vehicle, the operating principle was studied. A model of hydraulic brake system and corresponding control strategy were built with the co-simulation platform of AMESim and MATLAB. The impact factors of brake pressure change rate were analyzed theoretically. The influences of the main hydraulic parameters were analyzed through simulation, such as volume of brake fluid, type of pipe, ABS valve and brake clearance. The results provide a theoretical basis for the accurate control of wheel cylinder pressure.

Collaborative control of a dual electro-hydraulic regenerative brake system for a rear-wheel-drive electric vehicle

2018 ◽  
Vol 233 (4) ◽  
pp. 1035-1046 ◽  
Author(s):  
Jonathan Nadeau ◽  
Philippe Micheau ◽  
Maxime Boisvert
Keyword(s):  
Electric Vehicle ◽  
Energy Recovery ◽  
Rear Wheel ◽  
Brake System ◽  
Force Distribution ◽  
Hydraulic Brake ◽  
Brake Pressure ◽  
Wheel Drive ◽  
Brake Force ◽  
Brake Force Distribution

Within the field of electric vehicles, the cooperative control of a dual electro-hydraulic regenerative brake system using the foot brake pedal as the sole input of driver brake requests is a challenging control problem, especially when the electro-hydraulic brake system features on/off solenoid valves which are widely used in the automotive industry. This type of hydraulic actuator is hard to use to perform a fine brake pressure regulation. Thus, this paper focuses on the implementation of a novel controller design for a dual electro-hydraulic regenerative brake system featuring on/off solenoid valves which track an “ideal” brake force distribution. As an improvement to a standard brake force distribution, it can provide the reach of the maximum braking adherence and can improve the energy recovery of a rear-wheel-drive electric vehicle. This improvement in energy recovery is possible with the complete substitution of the rear hydraulic brake force with a regenerative brake force until the reach of the electric powertrain constraints. It is done by performing a proper brake pressure fine regulation through the proposed variable structure control of the on/off solenoid valves provided by the hydraulic platform of the vehicle stability system. Through road tests, the tracking feasibility of the proposed brake force distribution with the mechatronic system developed is validated.

Master cylinder pressure reduction logic for cooperative work between electro-hydraulic brake system and anti-lock braking system based on speed servo system

2020 ◽  
Vol 234 (13) ◽  
pp. 3042-3055
Author(s):  
Lu Xiong ◽  
Wei Han ◽  
Zhuoping Yu ◽  
Jian Lin ◽  
Songyun Xu
Keyword(s):  
Feedback Control ◽  
Closed Loop ◽  
Servo System ◽  
Brake System ◽  
Extreme Condition ◽  
Pressure Reduction ◽  
Cylinder Pressure ◽  
Master Cylinder ◽  
Braking System ◽  
Hydraulic Brake

As one feasible solution of brake-by-wire systems, electro-hydraulic brake system has been made available into production recently. Electro-hydraulic brake system must work cooperatively with the hydraulic control unit of anti-lock braking system. Due to the mechanical configuration involving electric motor + reduction gear, the electro-hydraulic brake system could be stiffer in contrast to a conventional vacuum booster. That is to say, higher pressure peaks and pressure oscillation could occur during an active anti-lock braking system control. Actually, however, electro-hydraulic brake system and anti-lock braking system are produced by different suppliers considering brake systems already in production. Limited signals and operations of anti-lock braking system could be provided to the supplier of electro-hydraulic brake system. In this work, a master cylinder pressure reduction logic is designed based on speed servo system for active pressure modulation of electro-hydraulic brake system under the anti-lock braking system–triggered situation. The pressure reduction logic comprises of model-based friction compensation, feedforward and double closed-loop feedback control. The pressure closed-loop is designed as the outer loop, and the motor rotation speed closed-loop is drawn into the inner loop of feedback control. The effectiveness of the proposed controller is validated by vehicle experiment in typical braking situations. The results show that the controller remains stable against parameter uncertainties in extreme condition such as low temperature and mismatch of friction model. In contrast to the previous methods, the comparison results display the improved dynamic cooperative performance of electro-hydraulic brake system and anti-lock braking system and robustness.

scholarly journals Influence of Selected Parameters and Different Methods of Implementing Vacuum Impregnation of Apple Tissue on Its Effectiveness

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 428
Author(s):  
Tomasz Guz ◽  
Leszek Rydzak ◽  
Marek Domin
Keyword(s):  
Relaxation Time ◽  
Viscosity Coefficient ◽  
Pressure Change ◽  
Vacuum Impregnation ◽  
Impregnation Method ◽  
Plant Materials ◽  
Change Rate ◽  
Time Relaxation ◽  
Maintenance Time ◽  
The Impact

The study provides comprehensive information on the vacuum impregnation process applied to plant materials. It aims (in traditional applications) to ensure impermeability and elimination of porosity of various materials. The process substantially accelerates mass transfer in the liquid–solid system. The study describes the course of the process and accompanying phenomena as well its effects on plant tissues. The aim of the investigations was to determine the impact of some impregnation parameters (pressure, pressure change rate, vacuum maintenance time, relaxation time, and the coefficient of impregnating liquid viscosity) and the mode of impregnation (wet, dry, cyclic wet) on the degree of filling the plant tissue with the impregnating solution. Jonagold apples were used as the study material. The investigations have revealed that changes in the vacuum impregnation parameters (vacuum maintenance time, relaxation time, pressure change rate in the system) and the impregnation method do not exert a significant impact on the effectiveness of the process as expressed by the degree of permeation of the impregnating solution into the tissue. The pressure value and the viscosity coefficient were the only parameters that had a significant effect on the impregnation yield.

Experimental design of control strategy based on brake pressure changes on wet and slippery surfaces of rough road for variable damper setting during braking with activated anti-lock brake system

2012 ◽  
Vol 226 (10) ◽  
pp. 1303-1324 ◽  
Author(s):  
Hakan Koylu ◽  
Ali Cinar
Keyword(s):  
Control Strategy ◽  
Electronic Control Unit ◽  
Control Unit ◽  
Pressure Change ◽  
Brake System ◽  
Damping Capacity ◽  
Passenger Cars ◽  
The Road ◽  
Brake Pressure ◽  
Braking Distance

In this study, the control strategy based on experimental study is established for a variable damper setting with activated anti-lock brake system. For this, anti-lock brake system braking tests have been conducted by using hard, medium–hard and soft dampers on a rough road which has wet and slippery surfaces. In anti-lock brake system tests, brake pressure has been measured. The brake pressure increasing and decreasing rates have been obtained using measured brake pressure. The control strategy has been designed by using threshold values acquired from these test results related to brake pressure. For this, firstly, the brake pressure change thresholds of damper providing the shortest braking distance are determined. Then, the damping capacity stage rules are designed by depending on the brake pressure thresholds corresponding to the road conditions. The control strategy performance has been evaluated during transitions between wet and slippery roads. The results show that this control strategy is effectively applied to passenger cars without any change in electronic control unit configuration of anti-lock brake system. For this control strategy, it is considerably important that the damper setting to provide the shortest braking distance is detected.

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