对一种全新的拥塞控制协议XCP(eXplicit Control Protocol)进行了研究。在分析传统TCP的拥塞控制机制不足的基础上,对XCP协议的拥塞头格式进行了剖析,给出了基于XCP协议实现拥塞控制的基本原理。最后通过对比实验,验证了XCP协议在拥塞...对一种全新的拥塞控制协议XCP(eXplicit Control Protocol)进行了研究。在分析传统TCP的拥塞控制机制不足的基础上,对XCP协议的拥塞头格式进行了剖析,给出了基于XCP协议实现拥塞控制的基本原理。最后通过对比实验,验证了XCP协议在拥塞控制性能上比传统的TCP协议更优越。展开更多
随着汽车电子技术的发展,ECU的功能越来越多,它们之间需要相互传递的信息量也逐渐增大。XCP协议的高效性、稳定性和移植性恰好能满足其传输需求。此外CAN总线仍在汽车总线领域占有不可动摇的地位。文章介绍了XCP on CAN的主要协议内容,...随着汽车电子技术的发展,ECU的功能越来越多,它们之间需要相互传递的信息量也逐渐增大。XCP协议的高效性、稳定性和移植性恰好能满足其传输需求。此外CAN总线仍在汽车总线领域占有不可动摇的地位。文章介绍了XCP on CAN的主要协议内容,并且研究其在CAN总线上的寻址工作原理。展开更多
The rising number of electronic control units （ECUs） in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the ...The rising number of electronic control units （ECUs） in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the explicit calibration protocol （XCP） and J1939 communication protocol to satisfy the need of calibrating multiple ECUs simultaneously. The messages in the controller area network （CAN） are defined in the J1939 protocol. Each CAN node can get its own calibration messages and information from other ECUs, and block other messages by qualifying the CAN messages with priority, source or destination address. The data field of the calibration message is designed with the XCP, with CAN acting as the transport layer. The calibration sessions are setup with the event-triggered XCP driver in the master node and the responding XCP driver in the slave nodes. Mirroring calibration variables from ROM to RAM enables the user to calibrate ECUs online. The application example shows that the multi-ECU calibration system can calibrate multiple ECUs simultaneously, and the main program can also accomplish its calculation and send commands to the actuators in time. By the multi-ECU calibration system, the calibration effort and time can be reduced and the variables in ECU can get a better match with the variables of other ECUs.展开更多
文摘The rising number of electronic control units （ECUs） in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the explicit calibration protocol （XCP） and J1939 communication protocol to satisfy the need of calibrating multiple ECUs simultaneously. The messages in the controller area network （CAN） are defined in the J1939 protocol. Each CAN node can get its own calibration messages and information from other ECUs, and block other messages by qualifying the CAN messages with priority, source or destination address. The data field of the calibration message is designed with the XCP, with CAN acting as the transport layer. The calibration sessions are setup with the event-triggered XCP driver in the master node and the responding XCP driver in the slave nodes. Mirroring calibration variables from ROM to RAM enables the user to calibrate ECUs online. The application example shows that the multi-ECU calibration system can calibrate multiple ECUs simultaneously, and the main program can also accomplish its calculation and send commands to the actuators in time. By the multi-ECU calibration system, the calibration effort and time can be reduced and the variables in ECU can get a better match with the variables of other ECUs.
