In order to solve the problem of artificial generation and low efficiency of test sequences for zone controller (ZC), a model-based automatic generation method of test sequence is proposed. Firstly, the timed automata...In order to solve the problem of artificial generation and low efficiency of test sequences for zone controller (ZC), a model-based automatic generation method of test sequence is proposed. Firstly, the timed automata model is established based on function analysis of the zone controller, and the correctness of the model is verified by UPPAAL. Then by parsing the timed automata model files, state information and transition conditions can be extracted to generate test case sets. Finally, according to the serialization conditions of test cases, the test cases are serialized into test sequences by using the improved depth first search algorithm. A case, the ZC controls the train running within its jurisdiction, shows that the method is correct and can effectively improve the efficiency of test sequence generation.展开更多
Developing the control of modem power converters is a very expensive and time-consuming task. Time to market can take unacceptable long. FPGA-based real-time simulation of a power stage with analog measured signals ca...Developing the control of modem power converters is a very expensive and time-consuming task. Time to market can take unacceptable long. FPGA-based real-time simulation of a power stage with analog measured signals can reduce significantly the cost and time of testing a product. This new approach is known as HIL （hardware-in-the-loop） testing. A general power converter consists of two main parts： a power level （main circuit） and a digital controller unit, which is usually realized by using some kind of DSP. Testing the controller HW and SW is quite problematic： live tests with a completely assembled converter can be dangerous and expensive. A low-power model of the main circuit can be built under laboratory conditions, but it will have parameters （e.g. time constants and relative losses） differing from the ones of the original system. The solution is the HIL simulation of the main circuit. With this method the simulator can be completely transparent for the controller unit, unlike other computer based simulation methods The subject of this paper is to develop such a real-time simulator using FPGA. The modeled circuit is a three-phase inverter, which is widely used in power converters of renewable energy sources.展开更多
This paper presents a novel design method of force rebalance control for the sense mode of micromachined vibratory gyroscopes.Specific theoretical deductions are performed to identify a precise linear model of the ope...This paper presents a novel design method of force rebalance control for the sense mode of micromachined vibratory gyroscopes.Specific theoretical deductions are performed to identify a precise linear model of the open loop system of the sense mode,which is crucial for the PI controller design.The frequency responses obtained by experimental tests agree well with those calculated with the theoretical model,indicating the accuracy of the theoretical analyses.Experimental results demonstrate that the bandwidth of the closed loop is extended to 94.8 Hz from 2.3 Hz in the open loop and the quadrature signal is suppressed by about 64 dBV in the closed loop system.The overshoot and stable time in the step response of the closed loop system are measured to be about 15% and 35 ms,respectively.The mode-splitting gyroscope with the closed loop controlled sense mode achieves a scale factor of 41.0 mV/deg/s with nonlinearity of 0.09% and asymmetry of 1%,and a bias instability of 4.0 °/h with angle random walk of 0.171 deg/h1/2.展开更多
文摘In order to solve the problem of artificial generation and low efficiency of test sequences for zone controller (ZC), a model-based automatic generation method of test sequence is proposed. Firstly, the timed automata model is established based on function analysis of the zone controller, and the correctness of the model is verified by UPPAAL. Then by parsing the timed automata model files, state information and transition conditions can be extracted to generate test case sets. Finally, according to the serialization conditions of test cases, the test cases are serialized into test sequences by using the improved depth first search algorithm. A case, the ZC controls the train running within its jurisdiction, shows that the method is correct and can effectively improve the efficiency of test sequence generation.
文摘Developing the control of modem power converters is a very expensive and time-consuming task. Time to market can take unacceptable long. FPGA-based real-time simulation of a power stage with analog measured signals can reduce significantly the cost and time of testing a product. This new approach is known as HIL （hardware-in-the-loop） testing. A general power converter consists of two main parts： a power level （main circuit） and a digital controller unit, which is usually realized by using some kind of DSP. Testing the controller HW and SW is quite problematic： live tests with a completely assembled converter can be dangerous and expensive. A low-power model of the main circuit can be built under laboratory conditions, but it will have parameters （e.g. time constants and relative losses） differing from the ones of the original system. The solution is the HIL simulation of the main circuit. With this method the simulator can be completely transparent for the controller unit, unlike other computer based simulation methods The subject of this paper is to develop such a real-time simulator using FPGA. The modeled circuit is a three-phase inverter, which is widely used in power converters of renewable energy sources.
文摘This paper presents a novel design method of force rebalance control for the sense mode of micromachined vibratory gyroscopes.Specific theoretical deductions are performed to identify a precise linear model of the open loop system of the sense mode,which is crucial for the PI controller design.The frequency responses obtained by experimental tests agree well with those calculated with the theoretical model,indicating the accuracy of the theoretical analyses.Experimental results demonstrate that the bandwidth of the closed loop is extended to 94.8 Hz from 2.3 Hz in the open loop and the quadrature signal is suppressed by about 64 dBV in the closed loop system.The overshoot and stable time in the step response of the closed loop system are measured to be about 15% and 35 ms,respectively.The mode-splitting gyroscope with the closed loop controlled sense mode achieves a scale factor of 41.0 mV/deg/s with nonlinearity of 0.09% and asymmetry of 1%,and a bias instability of 4.0 °/h with angle random walk of 0.171 deg/h1/2.
