Hydraulic Power Pump Test Procedure

1986 ◽  
Author(s):  
Keyword(s):  
Test Procedure ◽  
Hydraulic Power ◽  
Pump Test

Research on Design Methods and Experiments of the Electro-Hydraulic Power Steering Pump

2014 ◽  
Vol 986-987 ◽  
pp. 1125-1128 ◽  
Author(s):  
Yong Chen ◽  
Jing Jing Xia
Keyword(s):  
Design Method ◽  
Subsequent Development ◽  
Steering System ◽  
Hydraulic Power ◽  
Power Steering ◽  
Electronic Control System ◽  
Hydraulic Steering ◽  
Test Platform ◽  
Pump Test ◽  
Hydraulic Power Steering

In order to improve the performance of vehicle steering system and reduce the system energy consumption, the structure and operation principle of an electro-hydraulic power steering (EHPS) system with a electro-hydraulic steering pump are described, on this basis, with the function requirement of steering system, and by using vehicle design and fluid drive theory, the design method of this electro-hydraulic steering pump and its matching with the vehicle are presented. Through building electro-hydraulic steering pump test platform to test its performance parameters, the results prove the correctness and effectiveness of this kind of design method, provide the basis for subsequent development of the electronic control system.

Benefits from Computerized Adaptive Testing as Seen in Simulation Studies

1999 ◽  
Vol 15 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Lutz F. Hornke
Keyword(s):  
Measurement Error ◽  
Computerized Adaptive Testing ◽  
Test Procedure ◽  
Adaptive Testing ◽  
Parameter Estimates ◽  
Simulation Studies ◽  
Computerized Adaptive Test ◽  
Item Banks ◽  
Item Parameters ◽  
General Reliability

Summary: Item parameters for several hundreds of items were estimated based on empirical data from several thousands of subjects. The logistic one-parameter (1PL) and two-parameter (2PL) model estimates were evaluated. However, model fit showed that only a subset of items complied sufficiently, so that the remaining ones were assembled in well-fitting item banks. In several simulation studies 5000 simulated responses were generated in accordance with a computerized adaptive test procedure along with person parameters. A general reliability of .80 or a standard error of measurement of .44 was used as a stopping rule to end CAT testing. We also recorded how often each item was used by all simulees. Person-parameter estimates based on CAT correlated higher than .90 with true values simulated. For all 1PL fitting item banks most simulees used more than 20 items but less than 30 items to reach the pre-set level of measurement error. However, testing based on item banks that complied to the 2PL revealed that, on average, only 10 items were sufficient to end testing at the same measurement error level. Both clearly demonstrate the precision and economy of computerized adaptive testing. Empirical evaluations from everyday uses will show whether these trends will hold up in practice. If so, CAT will become possible and reasonable with some 150 well-calibrated 2PL items.

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