Heavy commercial vehicles and buses. Emergency braking on a defined path. Test method for trajectory measurement

2017 ◽  
Keyword(s):  
Test Method ◽  
Commercial Vehicles ◽  
Emergency Braking ◽  
Trajectory Measurement

scholarly journals Study on Theoretical Model and Test Method of Vertical Vibration of Elevator Traction System

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Qifeng Peng ◽  
Aihua Jiang ◽  
Hong Yuan ◽  
Guojian Huang ◽  
Shan He ◽  
...  
Keyword(s):  
Steel Wire ◽  
Reference Value ◽  
Vibration Characteristics ◽  
Test Method ◽  
Normal Operation ◽  
Analysis Model ◽  
Vibration Equation ◽  
Emergency Braking ◽  
Operation Conditions ◽  
Traction System

In order to study the dynamic characteristics of the elevator, the response characteristics of the elevator under normal operation and emergency braking conditions are analyzed. In this paper, the centralized mass discretization model is used to study the vibration characteristics of the elevator traction system under the external excitation. Firstly, the vibration equation of the elevator multi-degrees-of-freedom (abbreviated as DOF) system is established. Then, the vibration characteristics of the three DOF system are analyzed, and the natural frequencies and modes are obtained. The free vibration equation and forced vibration equation are obtained, and the theoretical solutions are obtained. Finally, the test method proposed in this paper is used to test the normal operation and emergency braking of the elevator. The test results show that, under normal operation conditions, the measured speed and distance errors are not more than 4.2%, the up running distance measured by the elevator is larger than the actual value, while the down running distance is smaller than the actual value; under emergency braking condition, because the steel wire rope can only bear the pulling force, the peak acceleration fluctuation in the up emergency braking process is large, while the down emergency braking acceleration fluctuation is small. Therefore, the elevator vibration analysis model and the vibration test method proposed in this paper can be used for the analysis of elevator dynamic performance, which has great reference value for the safety performance research of the elevator traction system.

Development of Fuel Consumption Test Method Standards for Heavy-Duty Commercial Vehicles in China

2011 ◽  
Author(s):  
Tianlei Zheng ◽  
Yuefu Jin ◽  
Zhao Wang ◽  
Michael Wang ◽  
Freda Fung ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Test Method ◽  
Heavy Duty ◽  
Commercial Vehicles

scholarly journals Selection of vehicles for fleet of transport company on the basis of observation of their operational reliability

2021 ◽  
Vol 23 (1) ◽  
pp. 184-194
Author(s):  
Tadeusz Dziubak ◽  
Tadeusz Wysocki ◽  
Sebastian Dziubak
Keyword(s):  
Quantitative Analysis ◽  
Urban Area ◽  
Quantitative Evaluation ◽  
Operational Reliability ◽  
Test Method ◽  
Commercial Vehicles ◽  
Reliability Indices ◽  
Failure Frequency ◽  
Selection For ◽  
Selection Of

The exploitation reliability of the contemporary light commercial vehicles of four makes is subject to a quantitative analysis in the article. The issue concerning the quantitative evaluation of the operational reliability of the fleet of the commercial vehicles in the transport company and their selection for this fleet is not very numerously described in the literature. For the purposes of evaluating the operational reliability, results of monitoring failures of 115 vehicles during their several years of exploitation in the similar conditions in the urban area and its surroundings were used. A proposed test method uses the relative quantitative measures of the operational reliability indices targeted at the mileage of vehicles and frequency of the failures. The aforementioned enabled to identify the make of the vehicles, which during exploitation was characterized by the lowest failure frequency and thus reliability. This, in turn, allowed for a favorable selection of the vehicles within the next years of the operation of the company. The results of the study confirmed the possibility of using the proposed method to evaluate the operational reliability of the commercial vehicles in any transport company.

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