Design and Experimental Validation of a Virtual Vehicle Control Concept for Testing Hybrid Vehicles Using a Hydrostatic Dynamometer

2014 ◽  
Author(s):  
Zhekang Du ◽  
Perry Y. Li ◽  
Kai Loon Cheong ◽  
Thomas R. Chase
Keyword(s):  
Hybrid Vehicle ◽  
Hybrid Vehicles ◽  
The Road ◽  
Hydraulic Hybrid ◽  
Virtual Vehicle ◽  
Control Concept ◽  
Hydraulic Hybrid Vehicle ◽  
The Difference ◽  
On The Road ◽  
And Control

An approach to control a hydrostatic dynamometer for the Hardware-In-the-Loop (HIL) testing of hybrid vehicles has been developed and experimentally tested. The hydrostatic dynamometer used, which is capable of regeneration, was specifically designed and built in-house to evaluate the fuel economy and control strategy of a hydraulic hybrid vehicle. The control challenge comes from the inertia of the dynamometer being only 3% of that of the actual vehicle so that the dynamometer must apply, in addition to any drag torques, acceleration/deceleration torques related to the difference in inertias. To avoid estimating the acceleration which would be a non-causal operation, a virtual vehicle concept is introduced. The virtual vehicle model generates a reference speed profile which represents the behavior of the actual vehicle if driven on the road. The dynamometer control problem becomes one of enabling the actual vehicle-dyno shaft to track the speed of the virtual vehicle, instead of directly applying a desired torque. A feedback/feedforward controller was designed based upon an experimentally validated dynamic model of the dynamometer. The approach was successfully tested on a power-split hydraulic hybrid vehicle with acceptable speed and torque tracking performance.

Virtual Vehicle Control Concept for Hydrostatic Dynamometer Control1

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Zhekang Du ◽  
Tan Cheng ◽  
Perry Y. Li ◽  
Kai Loon Cheong ◽  
Thomas R. Chase
Keyword(s):  
Low Cost ◽  
Hybrid Vehicle ◽  
Vehicle Speed ◽  
The Road ◽  
Hydraulic Hybrid ◽  
Virtual Vehicle ◽  
Control Concept ◽  
Acceleration And Deceleration ◽  
Hydraulic Hybrid Vehicle ◽  
On The Road

An approach for controlling a hydrostatic dynamometer for the hardware-in-the-loop (HIL) testing of hybrid vehicles is proposed and experimentally evaluated. The hydrostatic dynamometer, which is capable of absorbing and regenerating power, was specifically designed and built in-house to evaluate the fuel economy and control strategy of a hydraulic hybrid vehicle being developed. Unlike a chassis dynamometer whose inertia is similar to the inertia of the vehicle being tested, the inertia of this hydrostatic dynamometer is only 3% of the actual vehicle. While this makes the system low cost, compact, and flexible for testing vehicles with different weights and drag characteristics, control challenges result. In particular, the dynamometer must apply, in addition to the torques to mimic the wind and road drag, also the torques to mimic the acceleration and deceleration of the missing inertia. To avoid estimating the acceleration and deceleration, which would be a noncausal operation, a virtual vehicle concept is introduced. The virtual vehicle model generates, in response to the applied vehicle torque, a reference speed profile which represents the behavior of the actual vehicle if driven on the road. This reformulates the dynamometer control problem into one of enabling the actual vehicle dynamometer shaft to track the speed of the virtual vehicle, instead of directly applying a desired torque. To track the virtual vehicle speed, a controller with feedforward and feedback components is designed using an experimentally validated dynamic model of the dynamometer. The approach has been successfully tested on a power-split hydraulic hybrid vehicle with acceptable virtual vehicle speed and dynamometer torque tracking performance.

scholarly journals Different Rule-based Control Schemes for a Series Hydraulic Hybrid Vehicle

2016 ◽  
Vol 3 (1) ◽  
pp. 101
Author(s):  
Tri-Vien Vu
Keyword(s):  
Fuel Economy ◽  
Hybrid Vehicle ◽  
Power Source ◽  
Rule Based ◽  
Conventional Vehicle ◽  
Hydraulic Hybrid ◽  
Short Period ◽  
Control Schemes ◽  
Hydraulic Hybrid Vehicle ◽  
The Difference

In a hybrid hydraulic vehicle, the hydraulic accumulator is used as the secondary power source in addition to the engine to propel the vehicle. Since the accumulator is a passive power source, it will be only used to compensate the difference between the power demand and the power delivery by the engine. Obviously, the main energy consumption is the engine. Hence a straightforward strategy to improve the fuel economy is to reduce the engine operating period. In contrast, because of the low energy density characteristic, the accumulator can only afford the required power in a short period. As a consequence, the hydraulic hybrid vehicle has been concluded only suitable for start-stop-and-go driving pattern. This paper present different rule-based control schemes for a 3.5- ton series hydraulic hybrid truck. The simulation results indicate that by applying suitable control scheme, the proposed series hydraulic hybrid system offers improvements of fuel economy for both urban and highway driving condition. The improvement is of 42.67% and 36.56% for urban and highway driving conditions, respectively in comparison with the corresponding conventional vehicle.

Predictive Energy Management for Parallel Hydraulic Hybrid Passenger Vehicle

2010 ◽  
Author(s):  
Timothy O. Deppen ◽  
Andrew G. Alleyne ◽  
Kim A. Stelson ◽  
Jonathan J. Meyer
Keyword(s):  
Energy Management ◽  
Hybrid Vehicle ◽  
Management Problem ◽  
Transfer Energy ◽  
Hybrid Powertrain ◽  
Engine Torque ◽  
Engine Simulation ◽  
Hydraulic Hybrid ◽  
Displacement Pump ◽  
Hydraulic Hybrid Vehicle

In this paper, a model predictive control (MPC) approach is presented for solving the energy management problem in a parallel hydraulic hybrid vehicle. The hydraulic hybrid vehicle uses variable displacement pump/motors to transfer energy between the mechanical and hydraulic domains and a high pressure accumulator for energy storage. A model of the parallel hydraulic hybrid powertrain is presented which utilizes the Simscape/Simhydraulics toolboxes of Matlab. These toolboxes allow for a concise description of the relevant powertrain dynamics. The proposed MPC regulates the engine torque and pump/motor displacement in order to track a desired velocity profile while maintaining desired engine conditions. In addition, logic is applied to the MPC to prevent high frequency cycling of the engine. Simulation results demonstrate the capability of the proposed control strategy to track both a desired engine torque and vehicle velocity.

Determination of Resistance to Abrasive Wear. VIII. Influence of Softeners in Tests with the Akron-Croydon and Du Pont Machines

1949 ◽  
Vol 22 (1) ◽  
pp. 259-262
Author(s):  
J. F. Morley
Keyword(s):  
Unit Area ◽  
Published Data ◽  
The Road ◽  
Abrasive Surface ◽  
Abrasive Power ◽  
The Difference ◽  
On The Road ◽  
The Right ◽  
Abrasion Testing

Abstract These experiments indicate that softeners can influence abrasion resistance, as measured by laboratory machines, in some manner other than by altering the stress-strain properties of the rubber. One possible explanation is that the softener acts as a lubricant to the abrasive surface. Since this surface, in laboratory abrasion-testing machines, is relatively small, and comes repeatedly into contact with the rubber under test, it seems possible that it may become coated with a thin layer of softener that reduces its abrasive power. It would be interesting in this connection to try an abrasive machine in which a long continuous strip of abrasive material was used, no part of it being used more than once, so as to eliminate or minimize this lubricating effect. The fact that the effect of the softener is more pronounced on the du Pont than on the Akron-Croydon machine lends support to the lubrication hypothesis, because on the former machine the rate of wear per unit area of abrasive is much greater. Thus in the present tests the volume of rubber abraded per hr. per sq. cm. of abrasive surface ranges from 0.03 to 0.11 cc. on the du Pont machine and from 0.0035 to 0.0045 cc. on the Akron-Croydon machine. On the other hand, if the softener acts as a lubricant, it would be expected to reduce considerably the friction between the abrasive and the rubber and hence the energy used in dragging the rubber over the abrasive surface. The energy figures given in the right-hand columns of Tables 1 and 3, however, show that there is relatively little variation between the different rubbers. As a test of the lubrication hypothesis, it would be of interest to vary the conditions of test so that approximately the same amount of rubber per unit area of abrasive is abraded in a given time on both machines; this should show whether the phenomena observed under the present test conditions are due solely to the difference in rate of wear or to an inherent difference in the type of wear on the two machines. This could most conveniently be done by considerably reducing the load on the du Pont machine. In the original work on this machine the load was standardized at 8 pounds, but no figures are quoted to show how abrasion loss varies with the load. As an addition to the present investigation, it is proposed to examine the effect of this variation with special reference to rubbers containing various amounts and types of softener. Published data on the influence of softeners on the road wear of tire rubbers do not indicate anything like such large effects as are shown by the du Pont machine. This throws some doubt on the value of this machine for testing tire tread rubbers, a conclusion which is confirmed by information obtained from other workers.

Sign in / Sign up

Export Citation Format

Share Document