With the increase of the number and the complexity of city-bus ECUs (Electronic Control Units), point-to-point link method in traditional city-bus has caused the problems of information exchange, reliability and maintenance. In this paper, we defined the conception of CBIICS (City-Bus Information Integrated Control System) and constructed CBIICS framework with high speed CAN bus and low speed CAN bus so as to share information between different ECUs. In order to provide consistent control and status data in V mode-based CBIICS development process, we designed SAE J1939 communication database to implement ECU, message and signal management and query. According to the electrical devices of an actual city-bus, we finally designed and implemented city-bus lamp control experiment system based on SAE J1939 protocol.

For intelligence brakes in the electronic pneumatic brake system of commercial vehicles, the pressure change rate is used as the key control parameter and evaluation index. This can improve the brake safety, stability, and ride comfort of the vehicle. The real-time detection of the brake pressure change rate for commercial vehicles is the premise for realizing the accurate control of brake pressure change rate. Based on Poiseuille’s law, an efficient measurement method of brake pressure change rate is proposed for commercial vehicles, and a new measuring device with an isothermal container and laminar flow resistance tube as the core components is designed. Through thermal insulation performance tests, flow resistance tests and measurement accuracy tests, combined with simulations, the effects of structural parameters and copper wire filling density on the performance of the isothermal container are analyzed, and these key parameters are optimized to improve the thermal insulation performance. A tubular laminar flow resistance tube composed of 304 stainless steel capillaries in parallel is designed. The influence mechanism of core parameters such as the number, radius, and length of laminar flow channels on its performance is studied, and the optimal parameter array is selected to optimize its performance. The experimental platform for measuring brake pressure change rate is constructed. By comparing the measurement curve of brake pressure change rate under simulation and experiment, the correctness and effectiveness of the pressure change rate measurement principle and the key components for electronically controlled pneumatic brakes of commercial vehicles are verified to meet engineering requirements.

With the increase of the number and the complexity of city-bus ECUs (electronic control units), it needs to design city-bus information integrated control system for sharing information and implementing correlative, real-time control between these ECUs. Before city-bus information integrated control system development, it is necessary to simulate and analyse system performance. In this paper, we established CAN model with layered modeling method. According to CAN layered architecture, we implemented CAN model including physical layer model, MAC (Medium Access Control) sublayer model, LLC (logic link control) sublayer model and application layer model. For evaluating CAN network performance of city-bus information integrated control system, we defined message response time, network load and message repetition times as evaluation parameters. According to different message generation time, constant(15) condition and uniform_int(20, 50) condition, we finally simulated and analysed the network performance for city-bus information integrated control system. According to SAE J1939 protocol requirement, we concluded that all the messages satisfied with the system realtime requirement.

The pressure change rate (PCR) of the brake chamber is the key control parameter and evaluation index in the pneumatic braking system for intelligent braking. The PCR threshold value of commercial vehicle brake chambers for braking comfort is analyzed. The PCR measurement method based on a laminar flow resistance tube is proposed, and the PCR test system is designed. The simulation model of a PCR test system for commercial vehicle brake chambers is presented. By analyzing the simulation and experimental results, it is validated that the PCR test system of commercial vehicle brake chambers has the function of measuring PCR in real time. Finally, according to the MSA (Measurement System Analysis) evaluation method, the performance of the PCR test system for commercial vehicle brake chambers is analyzed, and the correctness and applicability of the test system are verified.

Mechanical testing can elucidate the relationship between material structure and guide the manufacturing process, yet the existing molding process apparatus often lacks sufficient integration of testing conditions, making it challenging to meet the demands of composite working environments. In this study, we developed a comprehensive set of molding test equipment capable of accommodating multiple mechanical load combinations to ascertain the elastic–plastic deformation behavior during the molding process. The testing apparatus comprises components for tension, torsion, and bending, and, through a modular structural design and an integrated communication network, it facilitates multi-mechanical load operations and multi-physical quantity control. This system enables the execution of molding tests under five distinct single or composite loading conditions and allows for the real-time collection of data pertaining to six physical quantities. We conducted test verification using the material from the permanent magnet traction motor stator coil of the China railway high-speed moving train (CR450). The results indicate that the comparative analysis error for individual tests remains within 7%, thereby ensuring the validity of the measurement data. Notably, in the stretching–bending composite condition tests, we observed a decrease in bending force and an increase in bending rebound following tensile loading. In the torsion–bending tests, both the bending force and rebound amount remained largely unchanged after torque application. This device offers valuable insights and mechanical testing support for the development of complex molding process apparatus for both metallic and non-metallic materials.