Browsing by Author "Schmidt, Ece Guran"

Now showing 1 - 6 of 6

Citation - WoS: 1
Citation - Scopus: 2
C-3 : configurable CAN FD controller: architecture, design and hardware implementation
(Ieee, 2017) Afsin, Mehmet Ertug; Schmidt, Klaus Werner; Schmidt, Ece Guran
CAN FD (Controller Area Network with Flexible Data Rate) is a new standard which provides a fast data rate while preserving the compatibility with CAN. In this paper, we propose the C-3 (Configurable CAN FD Controller) IP core architecture, which is compatible with the non-ISO CAN FD standard. C-3 supports up to 96 transmit and receive buffers. The transmit buffers are organized as mailboxes with CAN ID prioritization in frame transmission. A separate filter mask that can be configured by the user exists for each receive buffer. Different from existing CAN/CAN FD controllers, the numbers and sizes of transmit and receive buffers of C-3 can be configured at run time. To this end, C-3 enables the best use of a single controller hardware for different applications and enables improving the real-time communication performance. C-3 communicates with the host device over SPI without any specific interface requirements using the protocol that is developed in the scope of this paper. C-3 is implemented on an FPGA Evaluation Board and its functionality is verified at a data rate of 2 Mbps.
Citation - WoS: 2
Citation - Scopus: 6
Controller area network with priority queues and FIFO queues: improved schedulability analysis and message set extension
(inderscience Enterprises Ltd, 2016) Schmidt, Klaus Werner; Alkan, Burak; Schmidt, Ece Guran; Karani, Duygu Culum; Karakaya, Utku; 17337
Controller area network (CAN) enables communication of electronic control units (ECUs) via messages using priority-based arbitration, which requires the implementation of priority queues (PQs) in the ECU device driver. Nevertheless, it is possible that not all ECUs on a CAN support PQs but use FIFO queues (FQs) instead. In this case, the classical CAN scheduling model with PQs is not suitable for the computation of message worst-case responsetimes (WCRTs) that are essential for verifying the correct vehicle operation. This paper considers an existing scheduling model for CAN with both PQs and FQs. First, an improved algorithm for speeding up the WCRT computation is proposed. Second, the practical case where an existing CAN message set is extended by new messages is addressed. An original algorithm for assigning priorities to new messages while keeping the priority order of existing messages is developed. Both algorithms are evaluated by computational experiments.
Citation - WoS: 15
Citation - Scopus: 17
Distributed real-time protocols for industrial control systems: framework and examples
(Ieee Computer Soc, 2012) Schmidt, Klaus Werner; Schmidt, Ece Guran; 17337
The automation of today's large-scale industrial systems relies on the operation of distributed controller devices that perform local computations and exchange information via communication networks. The subject of this paper is the development of a family of shared-medium industrial communication protocols that support the transmission of real-time (RT) and nonreal-time (nRT) data among distributed controller devices. Different from existing protocols, we suggest to incorporate information that is available from the control application in the protocol definition. As a result, our protocols dynamically change the bandwidth allocation on the shared medium according to the instantaneous communication requirements while ensuring hard RT guarantees. Following the recent developments in industrial automation, our protocols can be realized as software layers on top of low-cost conventional Ethernet.
Citation - WoS: 1
Citation - Scopus: 1
Improved load distribution for controller area network
(Ieee, 2017) Batur, Ahmet; Schmidt, Klaus Werner; Schmidt, Ece Guran
The main requirement for the design of the controller are network (CAN) is to guarantee that each message response time is smaller than their specified deadline. In practical in-vehicle applications, messages on CAN are released with offsets in order to avoid message bursts that lead to undesirably large response times. In this paper, new algorithms for the choice of suitable message offsets are developed and it is shown that these algorithms outperform existing algorithms.
Citation - WoS: 6
Citation - Scopus: 7
Modeling distributed real-time systems in TIOA and UPPAAL
(Assoc Computing Machinery, 2016) Kartal, Yusuf Bora; Schmidt, Ece Guran; Schmidt, Klaus Werner; 17337
The mission- and life-critical properties of distributed real-time systems require concurrent modeling, analysis, and formal verification in the design stage. The timed input/output automata (TIOA) framework and the UPPAAL software package are two widely used modeling and verification tools for this purpose. To this end, we develop the algorithm TUConvert for converting distributed TIOA models to UPPAAL behavioral models and formally prove its correctness. We demonstrate the applicability of our algorithm by the formal verification of a distributed real-time industrial communication protocol that is modeled by TIOA.
Citation - WoS: 2
Citation - Scopus: 4
Offset assignment on controller area network: improved algorithms and computational evaluation
(Ieee, 2017) Batur, Ahmet; Schmidt, Klaus Werner; Schmidt, Ece Guran
The basic requirement for the design of the Controller Area Network (CAN) for in-vehicle communication is to guarantee that the worst-case response time (WCRT) of each message is smaller than their specified deadline. In addition, it is desired to achieve small WCRTs that leave sufficient slack to the message deadline. In order to address the specified objectives, the idea of offset scheduling has been introduced. In this setting, messages on CAN are released with offsets in order to avoid message bursts that lead to undesirably large response times. In order to use offset scheduling efficiently, it is required to assign a suitable offset to each message. To this end, a load distribution (LD) algorithm is proposed in the existing literature. The main contribution of this paper is the development of new algorithms for offset assignment on CAN. Evaluating different example scenarios, the paper shows that the proposed algorithms outperform the existing LD algorithm in most of the cases.