| Braking performance is an important indicator of the vehicle safety performance, which is directly related to traffic safety. With the improvement and development of China highway road quality and the increasing of vehicle speed, the people for the vehicle braking performance requirements are also rising. Currently, anti-force roller brake tester and platform brake tester are widely used in motor vehicle testing agency for testing vehicle braking performance.Vehicle detection and diagnosis of intelligent direction group has been completed more than 20 sets of equipment from different manufacturers for the motor vehicle testing agency in the past three years, which are currently in the subject vehicle applications. Group in the installation, commissioning and testing practice, found some deficiencies of platform brake tester, the more prominent is the Jilin Institute of Metrology test found the following problems: Platform brake tester brake sensor force verification under no-load and load both cases, finding that when a load is applied to the measured braking force is a relatively large difference between the measured load is not applied braking force, that is, respectively in the load, the load applied to 0.5t and 1t load is applied, each measurement point data using different braking standard dynamometer measured. Thus the load plate brake tester test results influence more prominent. In addition, the tester usage is generally low, which was installed of the motor vehicle testing agency, according to testing by staff reflect the detection values of plate brake inspection station reproducibility is not good, resulting in platform brake tester idle and waste.To solve these problems, this paper analyzes the main deficiencies of the prior research platform brake tester itself flat structure, identify error factors platform brake tester test results impact and design improvements platform brake tester mechanical structure, in order to achieve reduction small test error, the purpose of improving the accuracy of the test and measurement performance. So this paper mainly studies the following aspects:1. First, the structure and working principle platform brake tester were analyzed by establishing mechanical model in automobile brake tester, and identify the impact of vehicle braking performance test results of the factor parameter; then focus for the existing its structure mechanics analysis to identify factors that affect it error test results, these factors are mainly the braking force sensor "push", "pull" force affected by the way, Effect of orientation-defining structure, brake sensor and brake platen height difference between the impact and influence of axle load sensor positions, set forth factors causes; Finally, a more reasonable design, targeted to reduce the measurement error, improve test accuracy, the theoretical basis for the platform brake tester mechanical system design.2. On the basis of an error analysis to determine the overall scheme platform brake tester mechanical systems, and design the platform brake tester and calibration mechanical structure by Catia software. The mechanical design includes an integral frame design, brake platen design, mechanical design axle load sensor is connected, and mechanical systems used in the load cell selection. Finally, in order to confirm whether the rigidity of the mechanical structure of the actual project needs, by using ANSYS software and Hypermesh software, according to the maximum actual load its stiffness checked, it was found by the deformation and stress distribution cloud structure mechanical structural stiffness is in line with the design requirements; for labeling device also conducted the same analysis, so as to optimize the design of the structure and static analysis was provided.3. The computer test system includes hardware and software system. The hardware includes signal conditioning modules, data acquisition card, photoelectric switch selection signal and anti-jamming design. Lab VIEW software with the software part of the test system for a simple design, the main test items for each vehicle braking performance test were tested software design, including user login system, braking performance test software design and testing of the system flow chart draw. |
PDF Full Text Request