Controller Area Network Protocol Research Articles

Using DSP Algorithms for CRC in a CAN Controller

A controller area network (CAN) controller is an integral part of an electronic control unit, particularly in an advanced driver assistance system application, and its characteristics should always be advantageous in all aspects of functionality especially in real time application. The cost should be low, while maintaining the functionality and reliability of the technology. However, a CAN protocol implementing serial operation results in slow throughput, especially in a cyclical redundancy checking (CRC) unit. In this paper, digital signal processing (DSP) algorithms are implemented, namely pipelining, unfolding, and retiming the CAN controller in the CRC unit, particularly for the encoder and decoder sections. It must attain a feasible iteration bound, a critical path that is appropriate for a CAN system, and must obtain a superior design of a high-speed parallel circuit for the CRC unit in order to have a faster transmission rate. The source code for the encoder and decoder was formulated in the Verilog hardware description language.

FPGA Implementation of Manchester Line Encoding for Frame Length Compression Scheme in CAN(Controller Area Network) Controller

CAN(Controller Area Network) is now getting popular because of its expanding applications especially in automotive industry. CAN protocol uses NRZ(Non Return to Zero) line encoding. Long NRZ messages may cause problems in receivers such as clock drift means that if there are no edges, receivers lose tracks of bits. As a solutions, stuff bits are extra bits added to force transitions regardless of data. However, stuff bits cause jitters during transmission and due to this extra frame for stuff bits, it reduces the frame rate of the controller. In this paper, a frame length compression scheme to improve the features of CAN controller is presented. Modified Manchester Line Encoding is implemented in this CAN controller. The proposed scheme is synthesized on the Xilinx Virtex-5 FPGA by using Verilog HDL. The simulation results shows that the Modified Manchester Line Encoding is better than the original Line NRZ encoding technique in terms of clock synchronization and frame length compression in CAN communications.

Improved Automotive CAN Protocol Based on Payload Reduction and Selective Bit Stuffing

In this research paper, the implementation strategies of automotive controller area network protocol are investigated and the short messaging scheme with selective bit stuffing method to improve the effective utilization of its bandwidth has been proposed. There would be a sharp decrease in the performance of traditional CAN protocol because of considerable increase in the number of ECUs (Electronic Control Units) and infotainment gadgets connected in the vehicle architecture. The demand for safety, emission, diagnostics and comfort norms has steeply increased the number of messages in the 250 Kbps CAN network as the computational power of ECUs has gone up. To overcome this problem, the short CAN method has been proposed and the work is benchmarked with SAEJ1939 Heavy commercial vehicle CAN standard. The Matlab Simulink based short CAN has been modeled and the performance of the proposed system has evaluated using virtual instrument cluster. Experimental results have shown that compared to the traditional CAN, the proposed method has reduced the worst case response time of CAN extended frame from 160 μ sec to 144 μ sec. Selective bit stuffing technique has reduced the impact of bit stuffing over the payload and improved the utilization factor for the CAN bus without affecting the CAN message ID properties. The proposed algorithm has been modeled and simulated using CAN Matlab model Simulink and it has been verified using virtual CAN tool and real time CAN bus hardware.

Security-Aware Design Methodology and Optimization for Automotive Systems

In this article, we address both security and safety requirements and solve security-aware design problems for the controller area network (CAN) protocol and time division multiple access (TDMA)-based protocols. To provide insights and guidelines for other similar security problems with limited resources and strict timing constraints, we propose a general security-aware design methodology to address security with other design constraints in a holistic framework and optimize design objectives. The security-aware design methodology is further applied to solve a security-aware design problem for vehicle-to-vehicle (V2V) communications with dedicated short-range communication (DSRC) technology. Experimental results demonstrate the effectiveness of our approaches in system design without violating design constraints and indicate that it is necessary to consider security together with other metrics during design stages.

Battery Management through PLC-CAN Communication

This article presents a new method allowing data exchanges between a Battery Management System (BMS) and the application’s Energy Management System (EMS). The proposed solution is based on the Power Line Communication (PLC) technology and harnesses the versatility of the well-known Controller Area Network (CAN) protocol. This new PLC-CAN communication system is depicted in the context of the management of a distributed battery pack composed of several batteries connected in a star topology. Limits of the system are exposed, arising from the trade-off between the carrier frequency and the length of the power cables. A theoretical approach through simulation is proposed and shows the feasibility of the PLC-CAN system. Measurements realized on an experimental setup confirm the validity of this new physical medium for the CAN protocol.

Node-based scheduling method for easy migration from CAN to FlexRay in in-vehicle networking systems

As vehicles become more intelligent, in-vehicle networking (IVN) systems such as controller area network (CAN) are essential for the convenience and safety of drivers. To expand the applicability of IVN systems, attention is currently being focused on chassis networking systems that require increased network capacity and real-time capabilities. FlexRay was developed to replace CAN protocol in chassis networking systems, to remedy the shortage of transmission capacity and unsatisfactory real-time transmission delay of conventional CAN. However, FlexRay network systems require a complex scheduling method, which is a barrier to their implementation as chassis networking systems. In particular, if we want to migrate from a CAN network to a FlexRay network using the well-defined CAN message database, which has been specifically constructed for chassis networking systems by automotive vendors, a new type of scheduling method is necessary to reduce scheduling efforts during the software development process. This paper presents a node-based scheduling method for easy migration from a CAN network to a FlexRay network system. To demonstrate the feasibility of the technique, its performance is evaluated in terms of various software complexity indices.

Adaptive Fault Diagnosis Algorithm for Controller Area Network

A controller area network (CAN)-based distributed system may develop faults at run-time. These faults need to be detected and diagnosed. This paper proposes a new algorithm named adaptive fault diagnosis algorithm for CAN (AFDCAN). It is designed for low-cost resource-constrained distributed embedded systems. The proposed algorithm detects all faulty nodes on the CAN. It allows new node entry and reentry of repaired faulty nodes during a diagnostic cycle. AFDCAN is found to provide high fault tolerance and to ensure reliable communication. It uses single-channel communication deploying the bus-based standard CAN protocol. A hardware implementation of the proposed algorithm has been used to obtain the results. The results show that the proposed algorithm diagnoses all faults in the system. Analysis of the proposed algorithm proves that the algorithm uses a definite and bounded number of testing rounds and messages to complete one diagnostic cycle.

Integrating mixed transmission and practical limitations with the worst-case response-time analysis for Controller Area Network

The existing worst-case response-time analysis for Controller Area Network (CAN) calculates upper bounds on the response times of messages that are queued for transmission either periodically or sporadically. However, it does not support the analysis of mixed messages. These messages do not exhibit a periodic activation pattern and can be queued for transmission both periodically and sporadically. They are implemented by several higher-level protocols based on CAN that are used in the automotive industry. We extend the existing analysis to support worst-case response-time calculations for periodic and sporadic as well as mixed messages. Moreover, we integrate the effect of hardware and software limitations in the CAN controllers and device drivers such as abortable and non-abortable transmit buffers with the extended analysis. The extended analysis is applicable to any higher-level protocol for CAN that uses periodic, sporadic and mixed transmission modes.

Time domain analysis of the physical wiring for a star-like topology in high-speed controller area networks

The high-speed controller area network protocol supports a linear wiring topology. However, owing to productivity and cost concerns, actual networks in automotive applications may be configured in a star-like topology using joint connectors, with multiple stubs diverging from one point on the main bus; this type of configuration may lead to increased signal reflection and requires careful design of the physical wiring. In this study, the time response in a star-like joint-connector-based controller area network bus topology is analysed, and design guidelines for the physical wiring are presented. The effects of the number of stubs connected to a joint connector on the signal transmission are described and evaluated through experiments. Then, the time response through a joint connector with a diverse number of stubs is estimated, which gives a timing reference for designing the physical wiring in a star-like bus topology. Additionally, the effects of reflection between adjacent joint connectors are analysed together with the distance between joint connectors to ensure that no propagation delay degradation occurs.

Marcapasos transitorio a través de bolsa pericárdica

The existing worst-case response-time analysis for Controller Area Network (CAN) calculates upper bounds on the response times of messages that are queued for transmission either periodically or sporadically. However, it does not support the analysis of mixed messages. These messages do not exhibit a periodic activation pattern and can be queued for transmission both periodically and sporadically. They are implemented by several higher-level protocols based on CAN that are used in the automotive industry. We extend the existing analysis to support worst-case response-time calculations for periodic and sporadic as well as mixed messages. Moreover, we integrate the effect of hardware and software limitations in the CAN controllers and device drivers such as abortable and non-abortable transmit buffers with the extended analysis. The extended analysis is applicable to any higher-level protocol for CAN that uses periodic, sporadic and mixed transmission modes.

내부 궤환 제어 구조를 갖는 시스템의 네트워크형 분산 제어

In this paper, an idea of a network type distributed control of a system with inner loop control structure will be considered. Generally, in case of a control system with inner loop control structure, it is not easy to implement circuits and programming. Using network type distributed control structure, it will show how it is better than before. CAN(Controller Area Network) protocol which has been known that it has a high reliability on the signal in the various network protocols is used. Also, Arago’s Disk System which has a inner loop control stucture is made to validate effectiveness of the proposed method.

A Practical Wireless Attack on the Connected Car and Security Protocol for In-Vehicle CAN

Vehicle-IT convergence technology is a rapidly rising paradigm of modern vehicles, in which an electronic control unit (ECU) is used to control the vehicle electrical systems, and the controller area network (CAN), an in-vehicle network, is commonly used to construct an efficient network of ECUs. Unfortunately, security issues have not been treated properly in CAN, although CAN control messages could be life-critical. With the appearance of the connected car environment, in-vehicle networks (e.g., CAN) are now connected to external networks (e.g., 3G/4G mobile networks), enabling an adversary to perform a long-range wireless attack using CAN vulnerabilities. In this paper we show that a long-range wireless attack is physically possible using a real vehicle and malicious smartphone application in a connected car environment. We also propose a security protocol for CAN as a countermeasure designed in accordance with current CAN specifications. We evaluate the feasibility of the proposed security protocol using CANoe software and a DSP-F28335 microcontroller. Our results show that the proposed security protocol is more efficient than existing security protocols with respect to authentication delay and communication load.

Extending Worst Case Response-Time Analysis for Mixed Messages in Controller Area Network With Priority and FIFO Queues

The existing worst case response-time analysis for controller area network (CAN) with nodes implementing priority and First In First Out (FIFO) queues does not support mixed messages. It assumes that a message is queued for transmission either periodically or sporadically. However, a message can also be queued both periodically and sporadically using mixed transmission mode implemented by several higher level protocols for CAN that are used in the automotive industry. We extend the existing analysis for CAN to support any higher level protocol for CAN that uses periodic, sporadic, and mixed transmission of messages in the systems where some nodes implement priority queues, whereas others implement FIFO queues. In order to provide a proof of concept, we implement the extended analysis in a free tool, conduct an automotive-application case study, and perform comparative evaluation of the extended analysis with the existing analysis.

Automobile Control System using Controller Area Network

rapid development in electronics industries is making the automobile industries smarter day by day. More number of electronics subsystems are being integrated in the modern automobile which increases the wiring among the overall system, cost and reduces the system reliability. To overcome this problem of complex wiring, cost, system reliability and data interchange among different electronics subsystem, an automobile control system is designed using controller area network protocol. This paper describes the control system design using three nodes in the simulation tool. The simulation setup of CAN bus control system contains the software flowchart, the database and the experimental graphs which is obtained during data transfer between nodes. The system comprises of the engine ignition, speed, headlight and the hazard-light. The software part of the automobile control system is designed and sharing of data is fully realized among the node.

Performance Evaluation of Wireless Controller Area Network (WCAN) Using Token Frame Scheme

In this paper, a proposed new wireless protocol so-called wireless controller area network is introduced. WCAN is an adaptation of its wired cousin, controller area network protocol. The proposed WCAN uses token frame scheme in providing channel access to nodes in the system. This token frame method follows the example used in wireless token ring protocol which is a wireless network protocol that reduces the number of retransmissions as a result of collisions. This scheme based on CAN protocol allows nodes to share a common broadcast channel by taking turns in transmitting upon receiving the token frame that circulates around the network for a specified amount of time. The token frame allows nodes to access the network one at a time, giving `fair' chance to all nodes instead of competing against one another. This method provides high throughput in a bounded latency environment. The proposed WCAN protocol has been developed and simulated by means of QualNet simulator. The performances of this proposed protocol are evaluated from the perspective of throughput, end-to-end delay and packet delivery ratio, and are compared against the IEEE 802.11 protocol. Simulation results show that the proposed WCAN outperforms IEEE 802.11 based protocol by 62.5 % in terms of throughput with increasing network size. Also, it shows an improvement of 6 % compared to IEEE 802.11 standard at a higher data interval rate.

Design and implementation of a UPnP-can gateway for automotive environments

In this paper, we propose a universal plug and play (UPnP) — controller area network (CAN) gateway system using UPnP middleware for interoperability between external smart devices and an in-vehicle network. The proposed gateway consists of a UPnP communication device, a CAN communication device, and a device translator layer. In-vehicle devices are not usually IP-based, so we implemented an in-vehicle device manager in the UPnP communication device which is in the gateway. We developed a vehicle simulator to produce real vehicular data for performance analysis. The CAN communication device transmits and receives real-time vehicle data between the real vehicular simulator and external devices through the UPnP. The device translator layer configures a message frame for enabling seamless data input and output between the CAN and UPnP protocols. After implementation, we generated an internal-external service request and tested the result. Finally, we confirmed the service request and operation between external devices and the internal vehicular device. Additionally, for a variety of external device numbers and communication environments, we demonstrated the gateway performance by measuring the round trip time (RTT) for overall service implementation.

Designing a Reliable and Application Specific Controller Area Network Protocol for Intra-Communication of an Embedded System

By utilizing a CAN (Controller Area Network) bus, point to point wiring is substituted by a shared medium. This is done by adding hardware (embedded systems) to each control unit that uses CAN protocol. The main purpose of this study is communication software protocol design and implementation based on CAN protocol (on CAN) for intra-communication in a micro satellite that can be used for intra-communication of other embedded systems. This protocol is designed in the application layer and is conformed to MAC and PHY layers of CAN protocol.

Distributed Control to Ensure Proportional Load Sharing and Improve Voltage Regulation in Low-Voltage DC Microgrids

DC microgrids are gaining popularity due to high efficiency, high reliability, and easy interconnection of renewable sources as compared to the ac system. Control objectives of dc microgrid are: 1) to ensure equal load sharing (in per unit) among sources; and 2) to maintain low-voltage regulation of the system. Conventional droop controllers are not effective in achieving both the aforementioned objectives simultaneously. Reasons for this are identified to be the error in nominal voltages and load distribution. Though centralized controller achieves these objectives, it requires high-speed communication and offers less reliability due to single point of failure. To address these limitations, this paper proposes a new decentralized controller for dc microgrid. Key advantages are high reliability, low-voltage regulation, and equal load sharing, utilizing low-bandwidth communication. To evaluate the dynamic performance, mathematical model of the scheme is derived. Stability of the system is evaluated by eigenvalue analysis. The effectiveness of the scheme is verified through a detailed simulation study. To confirm the viability of the scheme, experimental studies are carried out on a laboratory prototype developed for this purpose. Controller area network protocol is utilized to achieve communication between the sources.

Experimental Study on Communication Delay of Powertrain System of Plug-In Hybrid Electric Vehicles

In order to contrast and analyze the real-time performance of the powertrain system of a plug-in hybrid electric vehicle, a mathematical model of the system delay is established under the circumstances that the transmission adopts the CAN (controller area network) protocol and the TTCAN (time-triggered CAN) protocol, respectively, and the interior of the controller adopts the foreground-background mode and the OSEK mode respectively. In addition, an experimental platform is developed to test communication delays of messages under 4 different implementation models. The 4 models are testing under the CAN protocol while the controller interior adopts the foreground-background mode; testing under the CAN protocol while the controller interior adopts the OSEK mode; testing under the TTCAN protocol while the controller interior adopts the foreground-background mode, and testing under the TTCAN protocol while the controller interior adopts the OSEK mode. The theoretical and testing results indicate that the communication delay of the OSEK mode is a little longer than the one of the foreground-background mode. Moreover, compared with the CAN protocol, the periodic message has a better real-time performance under the TTCAN protocol, while the nonperiodic message has a worse one.

Developing a Novel Shared-Clock Scheduling Protocol for Highly-Predictable Distributed Real-Time Embedded Systems

The Controller Area Network (CAN) protocol is widely used in the development of distributed real-time embedded systems. It has previously been shown that a Shared-Clock (S-C) scheduling algorithm can be used along with CAN protocol to implement time-triggered network architectures. Previous work in this area has led to the development of four S-C scheduling protocols called TTC-SCC1, TTC-SCC2, TTC-SCC3 and TTC-SCC4 schedulers. This paper first reviews the four schedulers. Second, the paper provides a more general model for the TTC-SCC2 scheduler. Third, the limitations of the various S-C schedulers are discussed and an alternative S-C scheduling protocol is developed; which is referred to as TTC-SCC5 scheduler. The five schedulers are then evaluated and compared against a number of criteria including jitter behavior and resource requirements for practical implementation on low-cost embedded microcontrollers. The results presented in the paper show that the TTC-SCC5 scheduler is advantageous over the others since it integrates their key features while maintaining low implementation costs.