Aiming at the application environment of paddy agricultural machinery with bumpy and undulating changes,the problems affecting the method for steering wheel angle measurement by MEMS gyroscope were analyzed,and a whee...Aiming at the application environment of paddy agricultural machinery with bumpy and undulating changes,the problems affecting the method for steering wheel angle measurement by MEMS gyroscope were analyzed,and a wheel angle measurement method combining Dual-MEMS gyroscope(dual MEMS gyroscope)and RTK-GNSS was designed.The adaptive weighting method was used to fuse the heading angle differentiation of RTK-GNSS,the MEMS gyroscope angle rate,and velocity data,and the rod-arm compensation was performed to accurately obtain the angle rates of the body and steering wheels of agricultural machinery;the difference between the combined angular rate of the steering wheel of the agricultural machinery and the angular rate of the agricultural machinery body was obtained,and the integrator is used to integrate the difference to get the wheel steering angle value,and the Kalman filter was designed to make feedback correction for the integration process of angle calculation to eliminate the errors caused by the gyroscope zero bias,random drift,and gyroscope rod arm effect,and to obtain the accurate value of wheel steering angle.A comparative test with the connecting rod wheel angle sensor was designed,and the results show that the maximum deviation is 4.99°,the average absolute average value is 1.61°,and the average standard deviation is 0.98°.The method in this study and the connecting rod wheel angle sensor were used on paddy farm machinery.The wheel angle measurement deviation of the proposed method and the connecting rod wheel angle sensor was not more than 1°,which is relatively small.It has good stability,speed adaptability,and dynamic responsiveness that meets the accuracy requirements of steering wheel angle measurement for paddy field agricultural machinery unmanned driving and can be used instead of connecting rod angle sensors for unmanned agricultural machinery.展开更多
The possible effects of angiotensin-converting enzyme inhibitors(ACEIs)or angiotensin Ⅱ receptor blockers(ARBs)on COVID-19 disease severity have generated considerable debate.We performed a single-center,retrospectiv...The possible effects of angiotensin-converting enzyme inhibitors(ACEIs)or angiotensin Ⅱ receptor blockers(ARBs)on COVID-19 disease severity have generated considerable debate.We performed a single-center,retrospective analysis of hospitalized adult COVID-19 patients in Wuhan,China,who had definite clinical outcome(dead or discharged)by February 15,2020.Patients on anti-hypertensive treatment with or without ACEI/ARB were compared on their clinical characteristics and outcomes.The medical records from 702 patients were screened.Among the 101 patients with a history of hypertension and taking at least one anti-hypertensive medication,40 patients were receiving ACEI/ARB as part of their regimen,and 61 patients were on antihypertensive medication other than ACEI/ARB.We observed no statistically significant differences in percentages of in-hospital mortality(28%vs.34%,P=0.46),ICU admission(20%vs.28%,P=0.37)or invasive mechanical ventilation(18%vs.26%,P=0.31)between patients with or without ACEI/ARB treatment.Further multivariable adjustment of age and gender did not provide evidence for a significant association between ACEI/ARB treatment and severe COVID-19 outcomes.Our findings confirm the lack of an association between chronic receipt of reninangiotensin system antagonists and severe outcomes of COVID-19.Patients should continue previous antihypertensive therapy until further evidence is available.展开更多
基金supported by Science and Technology Innovation 2030–“New Generation Artificial Intelligence”Major Project(Grant No.2021ZD011090202,No.2021ZD011090503)the National Key Research and Development Program of China(Grant No.2021YFD2000602)the National Natural Science Foundation of China(Grant No.32071913,No.32101623).
文摘Aiming at the application environment of paddy agricultural machinery with bumpy and undulating changes,the problems affecting the method for steering wheel angle measurement by MEMS gyroscope were analyzed,and a wheel angle measurement method combining Dual-MEMS gyroscope(dual MEMS gyroscope)and RTK-GNSS was designed.The adaptive weighting method was used to fuse the heading angle differentiation of RTK-GNSS,the MEMS gyroscope angle rate,and velocity data,and the rod-arm compensation was performed to accurately obtain the angle rates of the body and steering wheels of agricultural machinery;the difference between the combined angular rate of the steering wheel of the agricultural machinery and the angular rate of the agricultural machinery body was obtained,and the integrator is used to integrate the difference to get the wheel steering angle value,and the Kalman filter was designed to make feedback correction for the integration process of angle calculation to eliminate the errors caused by the gyroscope zero bias,random drift,and gyroscope rod arm effect,and to obtain the accurate value of wheel steering angle.A comparative test with the connecting rod wheel angle sensor was designed,and the results show that the maximum deviation is 4.99°,the average absolute average value is 1.61°,and the average standard deviation is 0.98°.The method in this study and the connecting rod wheel angle sensor were used on paddy farm machinery.The wheel angle measurement deviation of the proposed method and the connecting rod wheel angle sensor was not more than 1°,which is relatively small.It has good stability,speed adaptability,and dynamic responsiveness that meets the accuracy requirements of steering wheel angle measurement for paddy field agricultural machinery unmanned driving and can be used instead of connecting rod angle sensors for unmanned agricultural machinery.
基金This work was supported by Major Projects of National Science and Technology on New Drug Creation and Development(Nos.2020ZX09201001 and 2020ZX09201012)Chinese Academy of Medical Sciences(CAMS)Emergency Project of COVID-19(No.2020HY320001).
文摘The possible effects of angiotensin-converting enzyme inhibitors(ACEIs)or angiotensin Ⅱ receptor blockers(ARBs)on COVID-19 disease severity have generated considerable debate.We performed a single-center,retrospective analysis of hospitalized adult COVID-19 patients in Wuhan,China,who had definite clinical outcome(dead or discharged)by February 15,2020.Patients on anti-hypertensive treatment with or without ACEI/ARB were compared on their clinical characteristics and outcomes.The medical records from 702 patients were screened.Among the 101 patients with a history of hypertension and taking at least one anti-hypertensive medication,40 patients were receiving ACEI/ARB as part of their regimen,and 61 patients were on antihypertensive medication other than ACEI/ARB.We observed no statistically significant differences in percentages of in-hospital mortality(28%vs.34%,P=0.46),ICU admission(20%vs.28%,P=0.37)or invasive mechanical ventilation(18%vs.26%,P=0.31)between patients with or without ACEI/ARB treatment.Further multivariable adjustment of age and gender did not provide evidence for a significant association between ACEI/ARB treatment and severe COVID-19 outcomes.Our findings confirm the lack of an association between chronic receipt of reninangiotensin system antagonists and severe outcomes of COVID-19.Patients should continue previous antihypertensive therapy until further evidence is available.
