With the development of intelligent and netw orking technology in automobile,the malicious attacks against in-vehicle CAN netw orks are increasing day by day,and the problem of information safety in automobile is aggr...With the development of intelligent and netw orking technology in automobile,the malicious attacks against in-vehicle CAN netw orks are increasing day by day,and the problem of information safety in automobile is aggravated. In this regard,this paper analyzes the security loopholes and threats w hich the CAN bus faced,put forw ard a kind of anomaly detection algorithm for vehicle CAN bus. The method uses support vector machine algorithm to distinguish betw een normal message and abnormal message,so as to realize the CAN bus anomaly detection. Theoretical and experimental studies show that this method can effectively detect abnormal packets in the CAN bus w ith a detection rate of over 90%,w hich can effectively resist malicious attacks such as tampering and cheating on the vehicle CAN bus.展开更多
Technical features about CAN bus are described. One kind of scheme in Hotel Guest Room Service and Management System based on CAN bus is presented. The system's structure and main function are expounded. The work ...Technical features about CAN bus are described. One kind of scheme in Hotel Guest Room Service and Management System based on CAN bus is presented. The system's structure and main function are expounded. The work principle and design of the system's hardware and software are explained. The realization of the system's hardware and software is detailed from aspects of improving system's anti-jamming and fault self-examined capability, and the block diagram of each part's circuit is given. Finally, features of the system are summarized, and a comparison with the system based on RS485 was made to prove the advantages of the system. By practice, CAN bus in the system can transmit data steadily and reliably.展开更多
The paper introduced CAN (Controller Area Network) bus and CAN2.0 standard, the design of hardware frame-work multi-point communication based on CAN bus, and the software design method. At the same time, the system ...The paper introduced CAN (Controller Area Network) bus and CAN2.0 standard, the design of hardware frame-work multi-point communication based on CAN bus, and the software design method. At the same time, the system normal communication function and stability were shown in the experiment.展开更多
A design proposal for twin-wire pulsed MIG welding power supply based on DSP ( digital signal processor) and CAN ( controller area network ) is put forward. By ase of the CAN bus, the synergic control between the ...A design proposal for twin-wire pulsed MIG welding power supply based on DSP ( digital signal processor) and CAN ( controller area network ) is put forward. By ase of the CAN bus, the synergic control between the master and slave power supplies can be realized. And in this way, their peak currents can be guaranteed to be alternative and the interference between the two arcs can be decreased efficiently. The hardware design, software design and relative tests are provided in this paper. Tests show that the power supply can meet the design requirements of twin-wire welding.展开更多
In order to make automatic mechanical transmission (AMT) capable of performing fault self-diagnoses and adaptive to standard communication interface,through technical analysis and intensive study concerning on-board...In order to make automatic mechanical transmission (AMT) capable of performing fault self-diagnoses and adaptive to standard communication interface,through technical analysis and intensive study concerning on-board diagnostic protocols now widely applied in Europe and America,KWP2000 on CAN is accepted as a technological path.An AMT fault communication system using hardware-in-the-loop simulation by dSPACE is developed,and communications compatible with ISO 15031-6 is realized on this module.Moreover,a hand-held fault diagnosis instrument with built-in software is designed to facilitate communications with AMT fault communication module with accuracy,rapidity and stableness.Bench and real vehicle experimental results show that the developed instrument and module can perform the anticipated functions,so as to maintain steady communications under the KWP2000-on-CAN protocol.展开更多
A deconpling control strategy of inverter parallel system is proposed based on the equivalent output impedance of single phase voltage source SPWM (sinusoidal pulse width modulation) inverter. The active power and r...A deconpling control strategy of inverter parallel system is proposed based on the equivalent output impedance of single phase voltage source SPWM (sinusoidal pulse width modulation) inverter. The active power and reactive power are calculated in terms of output voltage and current of the inverter, and sent to the other inverters in the parallel system via controller area network (CAN) bus. By calculating and decoupling the circumfluence of the active power and reactive power, the inverters can share load current via the regulation of the reference-signal phase and amplitude. Experimental results of an 110V/2kVA inverter parallel system show the feasibility of the decoupling control strategy.展开更多
Large high-speed corn precision planters can significantly improve seeding efficiency,but at present,there is no mature control technology in China.This study proposed a novel low-cost control system for large high-sp...Large high-speed corn precision planters can significantly improve seeding efficiency,but at present,there is no mature control technology in China.This study proposed a novel low-cost control system for large high-speed corn precision planters based on multiple technologies such as embedded systems,controller area network(CAN),global positioning system(GPS),and Android development technology.The developed control system provided excellent expansion capabilities of more than 40 planter rows.Functions such as monitoring the planter status,adjusting seed density,calculating planting-area were realized.Field experiments were performed under different GPS frequencies(fGPS),travel speeds,and seed spacings.Results showed that the working area relative error index(REI)and fGPS were negatively correlated,and the planter can achieve 0.84%error under the fGPS of 10 Hz.When the travel speed was 10 km/h or 12 km/h,the average quality index(QI),miss index(MI),and precision index(PI)were superior to 92.84%,5.80%,and 18.57%under each seed spacing,respectively,QI and MI had no significant difference under each seed spacing(p<0.05).For a travel speed of 14 km/h,indexes values reached the worst level at seed spacing of 20 cm,but still met the requirements of Chinese national standards.The total cost of the control system for a 12-row corn precision planter is only 17.07%of similar products from abroad.In summary,the developed control system can achieve preferable performance and costs much less than similar products obtained from abroad,which is suitable for promotion in China or other developing countries.展开更多
To increase the accuracy and real-time performance of on-line assessment of maize planting,a CAN bus based maize monitoring system for precision planting was designed and tested both in laboratory and field.The system...To increase the accuracy and real-time performance of on-line assessment of maize planting,a CAN bus based maize monitoring system for precision planting was designed and tested both in laboratory and field.The system was mainly comprised of:(a)seeding rate sensors based on opposite-type infrared photoelectric cell for counting the dropping seeds;(b)a decimeter GPS receiver for acquiring planter position and operation speed;(c)a vehicle monitoring terminal based on ARM Cotex-m4 core chip to acquire and process the whole-system data;(d)a touchscreen monitor to display the planter performance for the operator;and(e)a buzzer alarm to sound a warning when skip and double seeding happened.Taking the applicability,dependability and feasibility of the monitoring system into consideration,the opposite-type infrared photoelectric sensors were selected and their deployment strategies in the 6-port seed tube were analyzed.To decrease the average response time,a distributed information communication structure was adopted.In this information communication mode,collectors were designed for each individual sensor and communicated with sensors through two-wire CAN bus.A sensor together with the designed collector is called a sensor node,and each of them worked individually and took the responsibility for acquiring,processing,and transiting the on-going information.Laboratory test results showed that the random error distribution was approximately normal,and by liner analysis,the system observed value and the true value had as a liner relationship with coefficient of determination R^(2)=0.9991.Series of field tests showed that the seeding rate maximum relative error of the 6-port seed tube was 2.92%,and the maximum root mean square error(RMSE)was about 1.64%.The monitoring system,including sensor nodes,vehicle monitoring terminal and a touch-screen monitor,was proved to be dependable and stable with more than 14 d of continuous experiments in field.展开更多
文摘With the development of intelligent and netw orking technology in automobile,the malicious attacks against in-vehicle CAN netw orks are increasing day by day,and the problem of information safety in automobile is aggravated. In this regard,this paper analyzes the security loopholes and threats w hich the CAN bus faced,put forw ard a kind of anomaly detection algorithm for vehicle CAN bus. The method uses support vector machine algorithm to distinguish betw een normal message and abnormal message,so as to realize the CAN bus anomaly detection. Theoretical and experimental studies show that this method can effectively detect abnormal packets in the CAN bus w ith a detection rate of over 90%,w hich can effectively resist malicious attacks such as tampering and cheating on the vehicle CAN bus.
文摘Technical features about CAN bus are described. One kind of scheme in Hotel Guest Room Service and Management System based on CAN bus is presented. The system's structure and main function are expounded. The work principle and design of the system's hardware and software are explained. The realization of the system's hardware and software is detailed from aspects of improving system's anti-jamming and fault self-examined capability, and the block diagram of each part's circuit is given. Finally, features of the system are summarized, and a comparison with the system based on RS485 was made to prove the advantages of the system. By practice, CAN bus in the system can transmit data steadily and reliably.
文摘The paper introduced CAN (Controller Area Network) bus and CAN2.0 standard, the design of hardware frame-work multi-point communication based on CAN bus, and the software design method. At the same time, the system normal communication function and stability were shown in the experiment.
基金This project was supported by National Natural Science Foundation of China(50375054).
文摘A design proposal for twin-wire pulsed MIG welding power supply based on DSP ( digital signal processor) and CAN ( controller area network ) is put forward. By ase of the CAN bus, the synergic control between the master and slave power supplies can be realized. And in this way, their peak currents can be guaranteed to be alternative and the interference between the two arcs can be decreased efficiently. The hardware design, software design and relative tests are provided in this paper. Tests show that the power supply can meet the design requirements of twin-wire welding.
基金Sponsored by the National High-Tech Research and Development Program of China(2006AA110115)
文摘In order to make automatic mechanical transmission (AMT) capable of performing fault self-diagnoses and adaptive to standard communication interface,through technical analysis and intensive study concerning on-board diagnostic protocols now widely applied in Europe and America,KWP2000 on CAN is accepted as a technological path.An AMT fault communication system using hardware-in-the-loop simulation by dSPACE is developed,and communications compatible with ISO 15031-6 is realized on this module.Moreover,a hand-held fault diagnosis instrument with built-in software is designed to facilitate communications with AMT fault communication module with accuracy,rapidity and stableness.Bench and real vehicle experimental results show that the developed instrument and module can perform the anticipated functions,so as to maintain steady communications under the KWP2000-on-CAN protocol.
基金supported by the National Natural Science Foundation of China under Grant No 50677056
文摘A deconpling control strategy of inverter parallel system is proposed based on the equivalent output impedance of single phase voltage source SPWM (sinusoidal pulse width modulation) inverter. The active power and reactive power are calculated in terms of output voltage and current of the inverter, and sent to the other inverters in the parallel system via controller area network (CAN) bus. By calculating and decoupling the circumfluence of the active power and reactive power, the inverters can share load current via the regulation of the reference-signal phase and amplitude. Experimental results of an 110V/2kVA inverter parallel system show the feasibility of the decoupling control strategy.
基金This study was supported by the National Key Research and Development Program of China(Grant No.2017YFD0700703)the National Natural Science Foundation of China(Grant No.51575515)the National Industry System of Corn Technology of China(CARS-02).
文摘Large high-speed corn precision planters can significantly improve seeding efficiency,but at present,there is no mature control technology in China.This study proposed a novel low-cost control system for large high-speed corn precision planters based on multiple technologies such as embedded systems,controller area network(CAN),global positioning system(GPS),and Android development technology.The developed control system provided excellent expansion capabilities of more than 40 planter rows.Functions such as monitoring the planter status,adjusting seed density,calculating planting-area were realized.Field experiments were performed under different GPS frequencies(fGPS),travel speeds,and seed spacings.Results showed that the working area relative error index(REI)and fGPS were negatively correlated,and the planter can achieve 0.84%error under the fGPS of 10 Hz.When the travel speed was 10 km/h or 12 km/h,the average quality index(QI),miss index(MI),and precision index(PI)were superior to 92.84%,5.80%,and 18.57%under each seed spacing,respectively,QI and MI had no significant difference under each seed spacing(p<0.05).For a travel speed of 14 km/h,indexes values reached the worst level at seed spacing of 20 cm,but still met the requirements of Chinese national standards.The total cost of the control system for a 12-row corn precision planter is only 17.07%of similar products from abroad.In summary,the developed control system can achieve preferable performance and costs much less than similar products obtained from abroad,which is suitable for promotion in China or other developing countries.
基金We acknowledge that this work was financially supported by the National Key Research and Development Program of China(2017YFD0700604,2017YFD0700701)the Beijing Science&Technology Plan Project(D161100003216001)the academy of science and technology innovation team program supported by Beijing Academy of Agriculture and Forestry(JNKYT201607).
文摘To increase the accuracy and real-time performance of on-line assessment of maize planting,a CAN bus based maize monitoring system for precision planting was designed and tested both in laboratory and field.The system was mainly comprised of:(a)seeding rate sensors based on opposite-type infrared photoelectric cell for counting the dropping seeds;(b)a decimeter GPS receiver for acquiring planter position and operation speed;(c)a vehicle monitoring terminal based on ARM Cotex-m4 core chip to acquire and process the whole-system data;(d)a touchscreen monitor to display the planter performance for the operator;and(e)a buzzer alarm to sound a warning when skip and double seeding happened.Taking the applicability,dependability and feasibility of the monitoring system into consideration,the opposite-type infrared photoelectric sensors were selected and their deployment strategies in the 6-port seed tube were analyzed.To decrease the average response time,a distributed information communication structure was adopted.In this information communication mode,collectors were designed for each individual sensor and communicated with sensors through two-wire CAN bus.A sensor together with the designed collector is called a sensor node,and each of them worked individually and took the responsibility for acquiring,processing,and transiting the on-going information.Laboratory test results showed that the random error distribution was approximately normal,and by liner analysis,the system observed value and the true value had as a liner relationship with coefficient of determination R^(2)=0.9991.Series of field tests showed that the seeding rate maximum relative error of the 6-port seed tube was 2.92%,and the maximum root mean square error(RMSE)was about 1.64%.The monitoring system,including sensor nodes,vehicle monitoring terminal and a touch-screen monitor,was proved to be dependable and stable with more than 14 d of continuous experiments in field.