Scheduling the CAN Bus with Rate Monotonic Techniques

2011 ◽  
Vol 383-390 ◽  
pp. 4318-4322
Author(s):  
Zai Ping Chen ◽  
Yan Lei Guo

Controller Area Network (CAN) is widely used in real-time automobile control and is gaining wider acceptance as a standard for factory automation. This paper discusses the applicability of Rate Monotonic (RM) techniques to the scheduling of CAN messages. Rate Monotonic can guarantee higher network utilization, but it is difficult to implement in periodic data networks or local buses. The paper mainly analyzes the RM scheduling algorithm and then establishes the simulation model about the algorithm based on CAN bus, and analyzes the effect in this situation of experiment.

Author(s):  
Leena Das ◽  
Sourav Mohapatra ◽  
Durga Prasad Mohapatra

<p>Real-Time Monotonic algorithm (RMA) is a widely used static priority scheduling algorithm. For application of RMA at various systems, it is essential to determine the system’s feasibility first. The various existing algorithms perform the analysis by reducing the scheduling points in a given task set. In this paper we propose a schedubility test algorithm, which reduces the number of tasks to be analyzed instead of reducing the scheduling points of a given task. This significantly reduces the number of iterations taken to compute feasibility. This algorithm can be used along with the existing algorithms to effectively reduce the high complexities encountered in processing large task sets. We also extend our algorithm to multiprocessor environment and compare number of iterations with different number of processors. This paper then compares the proposed algorithm with existing algorithm. The expected results show that the proposed algorithm performs better than the existing algorithms.</p>


Author(s):  
Yingji Liu ◽  
Kan Zhao ◽  
Chen Ding ◽  
Yu Yao

Real-time remote monitoring and fault diagnosis for commercial buses has important significance in reducing the occurrence of potential accidents. This paper presents a real-time remote monitoring system for the running state of commercial passenger buses. The vehicle Controller Area Network (CAN) bus is able to collect the information of key indicators being monitored, such as brake pressure, oil pressure and fault code. Then, the collected data are uploaded to the central remote monitoring platform through a General Packet Radio Service (GPRS) module for further analysis and decision-making. In this work, a classification based data acquisition method and a hybrid configuration data transmission method are proposed to improve the efficiency of data acquisition and transmission. The authors also proposed a Run-length based relative coding algorithm to compress the massive monitoring data. Experimental results shows the average data compression ratio is 32.17%, which effectively reduces the data transmission cost.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Lisheng Jin ◽  
Qingning Niu ◽  
Haijing Hou ◽  
Huacai Xian ◽  
Yali Wang ◽  
...  

Driver cognitive distraction is a hazard state, which can easily lead to traffic accidents. This study focuses on detecting the driver cognitive distraction state based on driving performance measures. Characteristic parameters could be directly extracted from Controller Area Network-(CAN-)Bus data, without depending on other sensors, which improves real-time and robustness performance. Three cognitive distraction states (no cognitive distraction, low cognitive distraction, and high cognitive distraction) were defined using different secondary tasks. NLModel, NHModel, LHModel, and NLHModel were developed using SVMs according to different states. The developed system shows promising results, which can correctly classify the driver’s states in approximately 74%. Although the sensitivity for these models is low, it is acceptable because in this situation the driver could control the car sufficiently. Thus, driving performance measures could be used alone to detect driver cognitive state.


2013 ◽  
Vol 787 ◽  
pp. 982-986
Author(s):  
Zhi Yan Ma ◽  
Zong Mei Tang ◽  
Guang You Yang ◽  
Xu Wu Su

By studying static scheduling algorithm Deadline Monotonous Scheduling (DMS) which assigns the priority fixedly to each message based on its deadline before starting the system and dynamic scheduling algorithm Earliest Deadline First (EDF) which assigns the priority dynamically based on its remaining deadline in the running time of system, combining the cheap CPU cost of DMS and high network utilization of EDF and using the layered structure, we presented a hybrid scheduling algorithm with considering critical level of messages. Based on the work mentioned above, the simulation platform of CANbus is developed with MATLAB/SimEvents tool box. The platform was used to real-time analysis for the scheduling algorithms mentioned before, the simulation results showed that the hybrid scheduling algorithm could not only improve the real-time performance of system, but also reduce the cost of processor.


2013 ◽  
Vol 579-580 ◽  
pp. 792-797
Author(s):  
Yan Wang ◽  
Zhong Da Yu ◽  
Chen Xing Bao ◽  
Dong Xiang Shao

In this paper, we realize a real-time communication based on wireless local area network (WIFI) and controller area network (CAN) bus and develop a distributed control system for an automated guided vehicle (AGV). The system consists of two levels: (1) communication between AGVs and main computer based on WIFI, (2) communicationg between control units of AGV based on CAN bus. A real-time operating system μC/OS-II was used to control time, which significantly reduces the time for program and improves development efficiency. Finally, a small-size distributed AGV controller is developed as the main control unit of AGV and a distributed I/O system is developed based on it.


2021 ◽  
Vol 336 ◽  
pp. 05031
Author(s):  
Xiaochun Wang

Huawei LiteOS is a real-time operating system. Thread schedulability is an important thing to be considered first when we use the RTOS in an application. There are a lot of methods to value thread schedulability in practical application. Rate monotonic scheduling algorithm is a widely used static priority scheduling algorithm. We discussed the thread schedulability in Huawei LiteOS.


2021 ◽  
Vol 54 (1) ◽  
pp. 1-37 ◽  
Author(s):  
Emad Aliwa ◽  
Omer Rana ◽  
Charith Perera ◽  
Peter Burnap

As connectivity between and within vehicles increases, so does concern about safety and security. Various automotive serial protocols are used inside vehicles such as Controller Area Network (CAN), Local Interconnect Network (LIN), and FlexRay. CAN Bus is the most used in-vehicle network protocol to support exchange of vehicle parameters between Electronic Control Units (ECUs). This protocol lacks security mechanisms by design and is therefore vulnerable to various attacks. Furthermore, connectivity of vehicles has made the CAN Bus vulnerable not only from within the vehicle but also from outside. With the rise of connected cars, more entry points and interfaces have been introduced on board vehicles, thereby also leading to a wider potential attack surface. Existing security mechanisms focus on the use of encryption, authentication, and vehicle Intrusion Detection Systems (IDS), which operate under various constraints such as low bandwidth, small frame size (e.g., in the CAN protocol), limited availability of computational resources, and real-time sensitivity. We survey and classify current cryptographic and IDS approaches and compare these approaches based on criteria such as real-time constraints, types of hardware used, changes in CAN Bus behaviour, types of attack mitigation, and software/ hardware used to validate these approaches. We conclude with mitigation strategies limitations and research challenges for the future.


2020 ◽  
Vol 4 (2) ◽  
pp. 44
Author(s):  
Mohammad J. M. Zedan

The revolution in the automotive industry over time led to more and more electronics to be included in the vehicle and this increased the number and space allocated for cables. Therefore, the in-vehicle cabling network has been replaced with a two-wire bus serial communications protocol called Controller Area Network (CAN). The proposed paper describes the implementation of the CAN controller as a listener to monitor the state of the CAN bus in a real-time approach. The CAN listener obtains the data from the CAN bus by using an external signals converter. The work is realized using development platform called ZedBoard. The controller performs a sequence of processes on the received CAN frames including decoding, buffering and filtering. The processed data is stored in an implemented FIFO to keep the data from loss. After that, the data is sent serially to the processor system over the implemented SPI that connects the controller with the processor of the Zynq-7000 device. A single-threaded, simple operating system is run over the processor to provide a set of libraries and drivers that are utilized to access specific processor functions. It enables the execution of the C code that was written to configure the operation of the onboard display unit. The design procedure and simulation process for the implemented CAN listener is achieved using the Xilinx ISE WebPACK environment, while the final complete design is properly tested and verified by connecting the module to a CAN network consisting of six CAN nodes.


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