Development of strategies for reducing the worst-case message response times on the Controller Area Network

Çelik, Vakkas
The controller area network (CAN) is the de-facto standard for in-vehicle communication. The growth of time-critical applications in modern cars leads to a considerable increase in the message tra c on CAN. Hence, it is essential to determine e cient message schedules on CAN that guarantee that all communicated messages meet their timing constraints. The aim of this thesis is to develop o set scheduling strategies that find feasible schedules for higher bus load levels compared to conventional CAN scheduling approaches. We formulate the o set scheduling as a constraint optimization problem that maximizes the sum of message slacks where slack is defined as the di erence between the deadline and the worst-case response time (WCRT) of a message. The constraint to ensure the feasibility of the schedules is keeping all slacks positive. In this respect we propose two heuristic o set scheduling algorithms which integrate an existing method for the WCRT analysis in the schedule computation. We apply our algorithms to various examples and compare the results with a well-known o set scheduling algorithm. The results show that our algorithms can generate feasible schedules at significantly high loads with run times shorter than 5 minutes.


A Frame packing method to improve the schedulability on CAN and CAN-FD /
Urul, Gökhan; Schmidt, Şenan Ece; Schmidt, Klaus Verner; Department of Electrical and Electronics Engineering (2015)
Controller Area Network (CAN) is the most widely used in-vehicle network. Today, vehicle applications can fill a CAN network's communication bandwidth to its limit. Hereby, the consumed bandwidth of an in-vehicle application depends on the efficiency of packing signal data into CAN message frames and on the suitability of the CAN message priority assignment such that all messages are schedulable. This thesis focuses on the problem of signal packing which is known to be and NP-hard problem. To this end, the ...
C³: configurable CAN FD controller: design, implementation and evaluation
Afşin, Mehmet Ertuğ; Schmidt, Şenan Ece; Schmidt, Klaus Werner; Department of Electrical and Electronics Engineering (2018)
CAN FD (Controller Area Network with Flexible Data Rate) is a new communication standard, compatible with CAN. Different from CAN, CAN FD switches to high data rate during data transmission and allows payloads up to 64 bytes. In this thesis, we propose C3: Configurable CAN FD Controller which features up to fully configurable 96 TX and 96 RX buffers organized as mailboxes. Each RX buffer has dedicated acceptance filters. The host MCU sees C3 as a memory mapped device and interfaces with it via SPI protocol ...
Controller area network with offset scheduling: improved offset assignment algorithms and computation of response time distributions
Batur, Ahmet; Schmidt, Klaus Werner; Schmidt, Şenan Ece; Department of Electrical and Electronics Engineering (2018)
The Controller Area Network (CAN) is the most widely-used in-vehicle communication bus in the automotive industry. CAN enables the exchange of data among different electronic control units (ECUs) of a vehicle via messages. The basic requirement for the design of CAN is to guarantee that the worst-case response time (WCRT) of each message is smaller than its specified deadline. Hereby, it is generally desired to achieve small WCRTs that leave sufficient slack to the message deadline. In addition, it has to b...
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Dynamic Distributed Dependable Real Time Ethernet Industrial Protocol (D3RIP) is a real time industrial communication protocol that runs over shared-medium Ethernet with COTS hardware. The protocol consists of an interface layer that enables time slotted communication and a coordination layer that guarantees collision avoidance and timely delivery of real time messages generated by the control application. At the current development stage, these two layers of the protocol are fully implemented and tested. T...
Computation of Response Time Distributions for Messages on the Controller Area Network
Batur, Ahmet; Schmidt, Şenan Ece; Schmidt, Klaus Verner (2018-08-23)
The response time of messages is an important parameter for the design of in-vehicle networks based on the controller area network (CAN). The message transmission on CAN is affected by several non-deterministic factors such as stuff bits that are added to CAN frames depending on the message payload or changing phases among the asynchronous CAN nodes because of clock drifts. The resulting probabilistic nature of message response times on CAN is captured by the response time distribution (RTD) that quantifies...
Citation Formats
V. Çelik, “Development of strategies for reducing the worst-case message response times on the Controller Area Network,” M.S. - Master of Science, Middle East Technical University, 2012.