Aiming at the problem of large energy consumption in hydraulic control system with large load and variable working conditions,based on the multi-level pressure switching control system(MPSCS),a multi-level pressure sw...Aiming at the problem of large energy consumption in hydraulic control system with large load and variable working conditions,based on the multi-level pressure switching control system(MPSCS),a multi-level pressure switching control system based on independent metering control is proposed combined with the independent metering control technology.The configuration principle of the system is given,the mathematical model of this system is established,and the control strategy of the system under 4 different working quadrants is put forward.Finally,the control performance and energy saving characteristics of the system are tested.The test results show that the switching of high and low pressure power supply has a certain effect on the response of step position and ramp position under impedance working condition.The displacement curves show slow climbing or abrupt change of ramp position,and the position accuracy is less than 1 mm.The multi-level pressure switching control system based on independent metering control can recover and store energy under the transcendence working conditions.The control accuracy is about 1 mm,and the energy recovery rate is about 70%~80%.展开更多
This paper analyses detection errors of blood pressure meter (BPM) based on oscillomatric method with pressure reducing system step by step. The errors of BPM detecting system severely affecting detection accuracy and...This paper analyses detection errors of blood pressure meter (BPM) based on oscillomatric method with pressure reducing system step by step. The errors of BPM detecting system severely affecting detection accuracy and precision were evaluated. It provided a novel algorithm not only ameliorating these errors but also with shorter detection cycle. In order to release cuff air in linearity, this paper also provide a method to control different valve supplied with different power to maintain a certain deflation rate at 4 mmHg/Step. The experiments of these tests are conducted under PC detecting platform developed specially for this usage. The hardware design of interface of microprocessor and the monitoring program based on C language make this detecting system can be transformed to single chip processor system. The final goal of this research is to bring to a portable wrist BPM product and this call for severe demand for power design. Through detecting 60 subjects with different blood pressure the result is that the maximum experimental standard deviations of systolic, diastolic and mean blood pressure are less than 6 mmHg. Comparing with the congeneric product of wrist BPM with nonuniform specification, this systems specification tallies with overall system accuracy demand defined in EN 1060 3.展开更多
When the electronic temperature sensor was incorporated into a system of soil water tension and the insidetube temperature was monitored in real time, it is concluded that the inside temperature increased by 26.9 ℃ a...When the electronic temperature sensor was incorporated into a system of soil water tension and the insidetube temperature was monitored in real time, it is concluded that the inside temperature increased by 26.9 ℃ and the inside pressure changed about 14.6 Kpa, when the pottery soil was replaced by the sealing plug. When the soil water was relatively stable in the experimental salvers, the in-side pressure stil varied regularly with the temperature. When the inside temperature increased by 22.2 ℃, the inside pressure varied about 7.4 Kpa. Through com-pensation calculation of the inside tension, the temperature in the warming and cooling periods was compensated, which was useful to correct the tension measurement errors induced from the changing temperature. When the measuring interval was 4 hours and the temperature difference was 18.1 ℃, the tension difference of both points was only 0.278 Kpa, compared to the difference up to 6.5 Kpa before compensation.展开更多
基金the National Natural Science Foundation of China(No.51575471)the Natural Science Foundation of Hebei Province(No.E2018203028).
文摘Aiming at the problem of large energy consumption in hydraulic control system with large load and variable working conditions,based on the multi-level pressure switching control system(MPSCS),a multi-level pressure switching control system based on independent metering control is proposed combined with the independent metering control technology.The configuration principle of the system is given,the mathematical model of this system is established,and the control strategy of the system under 4 different working quadrants is put forward.Finally,the control performance and energy saving characteristics of the system are tested.The test results show that the switching of high and low pressure power supply has a certain effect on the response of step position and ramp position under impedance working condition.The displacement curves show slow climbing or abrupt change of ramp position,and the position accuracy is less than 1 mm.The multi-level pressure switching control system based on independent metering control can recover and store energy under the transcendence working conditions.The control accuracy is about 1 mm,and the energy recovery rate is about 70%~80%.
文摘This paper analyses detection errors of blood pressure meter (BPM) based on oscillomatric method with pressure reducing system step by step. The errors of BPM detecting system severely affecting detection accuracy and precision were evaluated. It provided a novel algorithm not only ameliorating these errors but also with shorter detection cycle. In order to release cuff air in linearity, this paper also provide a method to control different valve supplied with different power to maintain a certain deflation rate at 4 mmHg/Step. The experiments of these tests are conducted under PC detecting platform developed specially for this usage. The hardware design of interface of microprocessor and the monitoring program based on C language make this detecting system can be transformed to single chip processor system. The final goal of this research is to bring to a portable wrist BPM product and this call for severe demand for power design. Through detecting 60 subjects with different blood pressure the result is that the maximum experimental standard deviations of systolic, diastolic and mean blood pressure are less than 6 mmHg. Comparing with the congeneric product of wrist BPM with nonuniform specification, this systems specification tallies with overall system accuracy demand defined in EN 1060 3.
基金Supported by Jiangsu Agricultural Self-innovation Fund[CX(13)3031]~~
文摘When the electronic temperature sensor was incorporated into a system of soil water tension and the insidetube temperature was monitored in real time, it is concluded that the inside temperature increased by 26.9 ℃ and the inside pressure changed about 14.6 Kpa, when the pottery soil was replaced by the sealing plug. When the soil water was relatively stable in the experimental salvers, the in-side pressure stil varied regularly with the temperature. When the inside temperature increased by 22.2 ℃, the inside pressure varied about 7.4 Kpa. Through com-pensation calculation of the inside tension, the temperature in the warming and cooling periods was compensated, which was useful to correct the tension measurement errors induced from the changing temperature. When the measuring interval was 4 hours and the temperature difference was 18.1 ℃, the tension difference of both points was only 0.278 Kpa, compared to the difference up to 6.5 Kpa before compensation.
