Research And Design Of Air Conditioning Controller Test System For Electric Vehicle

In the context of electrification,the proportion of electronic technology in electric vehicle is increasing.Air conditioning controller as the brain of air conditioning system for electric vehicle,the functions are becoming more and more complicated,and the degree of electrical complexity is becoming higher and higher.As a result,the test development cycle of air conditioning controller becomes longer,and the test difficulties become more prominent.Aiming at the problem that the circuit fault location of air conditioning controller is inaccurate and the strategy test is difficult to leave the real car,three key test techniques,namely the decision table,the basic path test and the directional graphic of fault propagation,are applied to the functional test,the strategy test and the circuit fault location of air conditioning controller respectively,and a reasonable test case is designed.The designed test system is combined with three test methods,and the test verification for the function test,the strategy test and the circuit fault location of air conditioning controller is realized.The main contents of this thesis are as follows:1.First,the key test technology of air conditioning controller for electric vehicle is researched.The principle of the air conditioning controller is analyzed,the decision table,the basic path test and the directional graphic of fault propagation in the test key technology theory are analyzed in detail,and the requirements of the test system are clarified.2.Secondly,according to the test key technology,the detailed test method of the air conditioning controller is designed.The decision table is used for the functional test of the air conditioning controller,and the design of 10 electrical function test cases is achieved.The basic path test is used for the strategy test,taking the heating strategy test as an example,the independent path set of the heating strategy program is determined,the designed test cases completely cover the execution of 9 independent paths in the heating strategy program.The directional graphic of fault propagation is used for the circuit fault location,and the result table of the fault location of each circuit module is obtained,which can accurately locate the circuit module faults of the 16 circuit fault sources of the air conditioning controller.3.Then according to the requirements of the test system,the hardware and software design of the air conditioning controller test system is completed.Including the design of the test system architecture,the design of test circuit board and its lower computer software,the design of the host computer interface and data processing program,the combination of the test system and three key test technologies is realized.4.Finally,the test environment is built,and the test system is verified and analyzed.Test and verify the 10 types of electrical functions of the air conditioning controller,select a heating strategy test case to verify the heating strategy test path,inject 4 types of circuit faults to verify the fault location,and the data obtained from the functional test,the strategy test and the circuit fault test are analyzed.The test results show that the test system can realize the test of the controller's 10 electrical functions.For the strategy test,the test case configured by the host computer can cover the corresponding program path in the heating strategy execution program.For the circuit fault location test,the test system can accurately locate the specific fault source in the 16 circuit modules.The test results verify that the designed test system proposed in this thesis meets the test requirements of the air conditioning controller in the function test,the strategy test and the circuit fault test.