Seamless Shifting Control Based on Power Balance Method in Emergency Braking Condition

2021 ◽  
Author(s):  
Zhenghong Lu ◽  
Jian Song ◽  
Liangyao Yu
Keyword(s):  
Energy Recovery ◽  
Control Method ◽  
Reducing Power ◽  
Control Flow ◽  
Balance Method ◽  
Regenerative Braking ◽  
Power Balance ◽  
Emergency Braking ◽  
Total Energy Balance ◽  
Drive Motor

Abstract Implementation of multi-speed transmission for battery electric vehicle (BEV) is considered as one of effective methods in improving dynamic capability, reducing power consumption and downsizing the powertrain. Considering two trends of automotive technology, advanced driving assistance system (ADAS) and BEV electric powertrain, equipped with a two-speed transmission, can enhance the performance of automatic emergency braking systems (AEBS). When downshift operation is executed during regenerative braking, the multi-speed transmission in first gear can provide adequate brake force capacity for hard braking requirement, improving efficiency of energy recovery of drive motor as well as eliminating the dynamic lag of active braking booster. To ensure both the braking command and downshift requirement, a seamless clutch-to-clutch shifting control strategy based on power balance method is developed by analyzing the frictional work of two friction clutches inside the gear box and the transformation process of kinetic energy of rotational mechanical elements. To maintain the total energy balance of the powertrain as the control objective, the active power compensation of the drive motor during shifting fills the energy gap of the whole transmission system. With the estimation of clutches’ friction torque and shifting stage analyzer, optimal drive motor torque command can be numerically solved and a complete shifting control flow is designed in this study. Simulation results demonstrate the effectiveness of proposed control method in achieving seamless downshifting during regenerative braking, enhancing AEBS performance and improving energy recovery efficiency.

Skid Control of Small Electric Vehicles with In-Wheel Motors (Effect of ABS and Regenerative Brake Timing Control on Emergency Braking)

2015 ◽  
Vol 789-790 ◽  
pp. 927-931
Author(s):  
Mohamad Heerwan bin Peeie ◽  
Hirohiko Ogino ◽  
Yoshio Yamamoto
Keyword(s):  
Electric Vehicles ◽  
Control Method ◽  
Brake System ◽  
Regenerative Braking ◽  
Timing Control ◽  
Safety Device ◽  
Hydraulic Unit ◽  
Emergency Braking ◽  
Hydraulic Brake ◽  
Space Limitation

This paper presents an active safety device for skid control of small electric vehicles with in-wheel motors. Due to the space limitation on the driving tire, a mechanical brake system was installed rather than hydraulic brake system. For the same reason, anti-lock brake system (ABS) that is a basic skid control method cannot be installed on the driving tire. During braking on icy road or emergency braking, the tire will be locked and the vehicle is skidding. To prevent tire lock-up and vehicle from skidding, we proposed the combination of ABS and regenerative brake timing control. The hydraulic unit of ABS is installed on the non-driving tire while the in-wheel motors on the driving tire will be an actuator of ABS to control the regenerative braking force. The performance of the ABS and regenerative brake timing control on the emergency braking situation is measured by the simulation. The simulation result shows that the combination of ABS and regenerative brake timing control can prevent tire lock-up and vehicle from skidding.

scholarly journals Segmented Power Supply Preset Control Method of High-Speed Rail Contactless Traction Power Supply System considering Regenerative Braking Energy Recovery

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Ruoqiong Li ◽  
Junjie Wang ◽  
Xuan Zhao ◽  
Xin Li
Keyword(s):  
Power Supply ◽  
Energy Recovery ◽  
High Speed ◽  
Control Method ◽  
Regenerative Braking ◽  
High Speed Rail ◽  
Traction Power Supply System ◽  
Traction Power Supply ◽  
Braking Energy Recovery ◽  
Traction Power

For high-speed rail with high energy consumption, the recovery and utilization of regenerative braking energy is essential to improve the energy consumption of high-speed rail. As a technical link, the energy bidirectional feed inductively coupled power transfer (ICPT) system can realize the regenerative braking energy recovery of the contactless traction power supply system. Furthermore, considering that the braking energy of the high-speed rail is the largest when entering the station during the whole line operation, the braking section of the station is mainly considered. This paper proposes a preset control method for segmented power supply of the energy bidirectional feed ICPT system considering regenerative braking energy recovery. By establishing the steady-state mathematical model of the bidirectional ICPT system, the influence of the internal phase-shift angles φ1 and φ2 and the external phase-shift angle γ on the operating state of the system is analyzed. To realize system synchronization under the operation of EMUs, a train braking model is established through force analysis, and a power preset controller is designed to realize the synchronous control of the power flow of the bilateral system. According to the braking process of the train entering the station, the switching control method of the segment coil under the different conditions of the single train entering the station and the multitrain entering the station is proposed to ensure the reliability and flexibility of the train power supply. The simulation results of the 350 kW ICPT system simulation model show that the system can operate stably when the power transmission simulation is switched, and the transmission efficiency can reach 89%, which proves the feasibility of the control method. Energy-saving estimates show that a single train can recover about 200–300 kWh of electric energy during single braking. The comparison with the measured data verifies the accuracy of the modeling in this paper.

scholarly journals Potential for Energy Recovery of Unpowered Configurations Using Power Balance Method Computations

2021 ◽  
pp. 1-11
Author(s):  
Ngonidzashe E. Mutangara ◽  
Lelanie Smith ◽  
Kenneth J. Craig ◽  
Drewan S. Sanders
Keyword(s):  
Energy Recovery ◽  
Balance Method ◽  
Power Balance

Time-Optimal Coordination Control for the Gear-Shifting Process in Electric-Driven Mechanical Transmission (Dog Clutch) without Impacts

2020 ◽  
Vol 9 (2) ◽  
pp. 155-168
Author(s):  
Ziwang Lu ◽  
◽  
Guangyu Tian ◽  
Keyword(s):  
Control Strategy ◽  
Position Control ◽  
Control Method ◽  
Synchronization Control ◽  
Mechanical Transmission ◽  
Coordination Control ◽  
Optimal Position ◽  
Drive Motor ◽  
Time Optimal ◽  
Optimal Coordination

Torque interruption and shift jerk are the two main issues that occur during the gear-shifting process of electric-driven mechanical transmission. Herein, a time-optimal coordination control strategy between the the drive motor and the shift motor is proposed to eliminate the impacts between the sleeve and the gear ring. To determine the optimal control law, first, a gear-shifting dynamic model is constructed to capture the drive motor and shift motor dynamics. Next, the time-optimal dual synchronization control for the drive motor and the time-optimal position control for the shift motor are designed. Moreover, a switched control for the shift motor between a bang-off-bang control and a receding horizon control (RHC) law is derived to match the time-optimal dual synchronization control strategy of the drive motor. Finally, two case studies are conducted to validate the bang-off-bang control and RHC. In addition, the method to obtain the appropriate parameters of the drive motor and shift motor is analyzed according to the coordination control method.

Dual-position excitation technique in flow control over an airfoil at low speeds

2018 ◽  
Vol 30 (9) ◽  
pp. 4141-4154
Author(s):  
Abbas Ebrahimi ◽  
Majid Hajipour ◽  
Kamran Ghamkhar
Keyword(s):  
Flow Control ◽  
Shear Layer ◽  
Control Method ◽  
Lift Coefficient ◽  
Shear Layers ◽  
Control Flow ◽  
Plasma Actuators ◽  
Dbd Plasma ◽  
Surface Shear ◽  
Content Type

PurposeThe purpose of this paper is to control flow separation over a NACA 4415 airfoil by applying unsteady forces to the separated shear layers using dielectric barrier discharge (DBD) plasma actuators. This novel flow control method is studied under conditions which the airfoil angle of attack is 18°, and Reynolds number based on chord length is 5.5 × 105.Design/methodology/approachLarge eddy simulation of the turbulent flow is used to capture vortical structures through the airfoil wake. Power spectral density analysis of the baseline flow indicates dominant natural frequencies associated with “shear layer mode” and “wake mode.” The wake mode frequency is used simultaneously to excite separated shear layers at both the upper surface and the trailing edge of the airfoil (dual-position excitation), and it is also used singly to excite the upper surface shear layer (single-position excitation).FindingsBased on the results, actuations manipulate the shear layers instabilities and change the wake patterns considerably. It is revealed that in the single-position excitation case, the vortices shed from the upper surface shear layer are more coherent than the dual-position excitation case. The maximum value of lift coefficient and lift-to-drag ratio is achieved, respectively, by single-position excitation as well as dual-position excitation.Originality/valueThe paper contributes to the understanding and progress of DBD plasma actuators for flow control applications. Further, this research could be a beneficial solution for the promising design of advanced low speed flying vehicles.

Measurement Method Research on Inertial Parameters of Motor Assembly

2013 ◽  
Vol 437 ◽  
pp. 663-668
Author(s):  
Ling Sun ◽  
Peng Yu ◽  
Tong Zhang
Keyword(s):  
Measurement Method ◽  
Center Of Mass ◽  
Moment Of Inertia ◽  
Balance Method ◽  
Test Error ◽  
Inertial Parameters ◽  
Drive Motor ◽  
Weight Method ◽  
Mass Position

Inertial parameters of the motor assembly include its mass, CM (center of mass) position, moment of inertia and product of inertia. Taking one vehicle drive motor as the research object, its mass and CM position are measured by using weight method and moment balance method respectively. Its moment of inertia and product of inertia are measured by using three-wire pendulum. On the basis of analyzing the test error, this paper proposed specific measures to reduce the test error.

Experimental Investigation of Hydraulic-Pneumatic Regenerative Braking System

2015 ◽  
Author(s):  
A. G. Agwu Nnanna ◽  
Erik Rolfs ◽  
James Taylor ◽  
Karla Ariadny Freitas Ferreira
Keyword(s):  
Experimental Investigation ◽  
Kinetic Energy ◽  
Power Output ◽  
Energy Recovery ◽  
Scale Model ◽  
Regenerative Braking ◽  
Gear Pump ◽  
Braking System ◽  
Light Duty ◽  
Overall Efficiency

Design and development of energy efficient vehicles is of paramount importance to the automobile industry. Energy efficiency can be enhanced through recovery of the kinetic energy lost in the form of waste heat during braking. The kinetic energy could be converted into a reusable energy source and aid in acceleration, hence the braking system would contribute to improving the overall efficiency of a vehicle. Hydraulic-Pneumatic Regenerative Braking (HPRB) systems are a hybrid drive system that works in tandem with a vehicle’s engine and drivetrain to improve efficiency and fuel-economy. A HPRB system functions by recovering the energy typically lost to heat during vehicle braking, and storing this energy as a reusable source that can propel a vehicle from a stop. The major advantages of a HPRB system are that a vehicle would not require its engine to run during braking to stop, nor would the engine be required to accelerate the vehicle initially from a stop. The benefit realized by this system is an increase in fuel-efficiency, reduced vehicle emissions, and overall financial savings. An HPRB system aids in slowing a vehicle by creating a drag on the driveline as it recovers and stores energy during braking. Therefore, HPRB system operation reduces wear by minimizing the amount of work performed by the brake pads and rotors. An experimental investigation of Hydraulic-Pneumatic Regenerative Braking (HPRB) system was conducted to measure the system’s overall efficiency and available power output. The HPRB in this study is a 1/10th lab-scale model of a light-duty four wheel vehicle. The design/size was based on a 3500 lbs light-duty four wheel vehicle with an estimated passenger weight of 500 lbs. It was assumed that the vehicle can accelerate from 0–15 mph in 2 seconds. The aim of this work is to examine the effect of heat losses due to irreversibility on energy recovery. The experimental facility consisted of a hydraulic pump, two hydraulic-pneumatic accumulators, solenoid and relief valves, and data acquisition system. The HPRB system did not include any driveline components necessary to attach this system onto a vehicle’s chassis rather an electric motor was used to drive the pump and simulate the power input to the system from a spinning drive shaft. Pressure transducers, Hall effects sensor, and thermocouples were installed at suction and discharge sections of the hydraulic and pneumatic components to measure hydrodynamic and thermos-physical properties. The measured data were used to determine the system’s energy recovery and power delivery efficiency. Results showed that the HPRB system is capable of recovering 47% of the energy input to the system during charging, and 64% efficient in power output during discharging with an input and output of 0.33 and 0.21 horsepower respectively. Inefficiencies during operation were attributed to heat generation from the gear pump but especially due to the piston accumulator, where heat loss attributed to a 12% reduction in energy potential alone.

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