No-tillage planters need to be equipped with row cleaners to remove post-harvest plant residue from the seedbed.The two-disc row cleaners cannot effectively remove the plant residue at high speed because the working d...No-tillage planters need to be equipped with row cleaners to remove post-harvest plant residue from the seedbed.The two-disc row cleaners cannot effectively remove the plant residue at high speed because the working depth is unstable,which leads to poor seeding quality of the seeder.A straw cleaning unit with double air springs was designed to achieve better straw cleaning performance at high speeds.The analysis of the mechanical characteristics of the double air spring system showed that it enabled separate adjustment of force and stiffness.A dynamic model of the straw cleaning unit was established,and the effectiveness of the double air spring system with adjustable stiffness in stabilizing the working depth of the row cleaners was analyzed.Field experiments were conducted to evaluate the straw cleaning performance and consistency of downforce against the ground of the straw cleaning unit with double air springs at different high speeds.The results showed that the stiffness of the double air spring system for better straw cleaning performance of the straw cleaning unit was different at different working speed,and the required stiffness increased as the working speed increased;When the working speed was 8-12 km/h,the coefficient of variation of cleaned strip width was 6.9%-12.1%,the straw cleaning rate was 81.6%-92.2%and the root mean square error of downforce was 19.93-28.63 N;the coefficient of variation of cleaned strip width was moderately positively correlated with the root mean square error of downforce,and the cleaned strip width consistency was better when the root mean square error of downforce was lower than 25.00 N.展开更多
Retinal surgery is one of the most delicate and complex operations,which is close to or even beyond the physiological limitation of the human hand.Robots have demonstrated the ability to filter hand tremors and motion...Retinal surgery is one of the most delicate and complex operations,which is close to or even beyond the physiological limitation of the human hand.Robots have demonstrated the ability to filter hand tremors and motion scaling which has a promising output in microsurgery.Here,we present a novel soft micron accuracy robot(SMAR)for retinal surgery and achieve a more precise and safer operation.A remote center of motion(RCM)parallelogram structure with a double spring adaptive balancing mechanism is designed and optimized to achieve precise motion and safer operation.The deviation from the expected trajectory with manual operation and robot-assisted operation is 143.06μm±91.27μm vs 26.39μm±13.22μm,which has been significantly improved}.We evaluated the safety performance of SMAR in live animals.Furthermore,preliminary human clinical trials showed that the robot-assisted has less drift compared to the manual operation with 41.07μm±20.78μm vs 299.66μm±85.84μm.The visual acuity with LogMAR of cases showed higher improvement in the robot-assisted group preliminary,which for manual of 0.78±0.44 vs robot-assisted 1.24±0.70 with no statistically significant difference.This study provides promising options for robot-assisted with very experienced surgeons in the most challenging microsurgery.The system has the potential to effectively reduce the training curve of doctors and alleviate the shortage of ophthalmic surgeons,which is very important for rural areas and underdeveloped countries.展开更多
基金supported by National Key Research and Development Program of China(Grant No.2023YFD1500404)Jilin Science and Technology Development Plan(Grant No.20220508113RC).
文摘No-tillage planters need to be equipped with row cleaners to remove post-harvest plant residue from the seedbed.The two-disc row cleaners cannot effectively remove the plant residue at high speed because the working depth is unstable,which leads to poor seeding quality of the seeder.A straw cleaning unit with double air springs was designed to achieve better straw cleaning performance at high speeds.The analysis of the mechanical characteristics of the double air spring system showed that it enabled separate adjustment of force and stiffness.A dynamic model of the straw cleaning unit was established,and the effectiveness of the double air spring system with adjustable stiffness in stabilizing the working depth of the row cleaners was analyzed.Field experiments were conducted to evaluate the straw cleaning performance and consistency of downforce against the ground of the straw cleaning unit with double air springs at different high speeds.The results showed that the stiffness of the double air spring system for better straw cleaning performance of the straw cleaning unit was different at different working speed,and the required stiffness increased as the working speed increased;When the working speed was 8-12 km/h,the coefficient of variation of cleaned strip width was 6.9%-12.1%,the straw cleaning rate was 81.6%-92.2%and the root mean square error of downforce was 19.93-28.63 N;the coefficient of variation of cleaned strip width was moderately positively correlated with the root mean square error of downforce,and the cleaned strip width consistency was better when the root mean square error of downforce was lower than 25.00 N.
基金supported by the National Science Foundation of China(Grant No.81700884)Key Research and Development Program of Zhejiang Province(Grant No.2025C01132)+2 种基金General Research Project of Education Department of Zhejiang Province(Grant No.Y202352078)Zhejiang Province Public Welfare Technology Application(Grant No.LGF21H120005)Funding of Central Government Guiding Local Science and Technology Development(Grant No.2023ZY1061).
文摘Retinal surgery is one of the most delicate and complex operations,which is close to or even beyond the physiological limitation of the human hand.Robots have demonstrated the ability to filter hand tremors and motion scaling which has a promising output in microsurgery.Here,we present a novel soft micron accuracy robot(SMAR)for retinal surgery and achieve a more precise and safer operation.A remote center of motion(RCM)parallelogram structure with a double spring adaptive balancing mechanism is designed and optimized to achieve precise motion and safer operation.The deviation from the expected trajectory with manual operation and robot-assisted operation is 143.06μm±91.27μm vs 26.39μm±13.22μm,which has been significantly improved}.We evaluated the safety performance of SMAR in live animals.Furthermore,preliminary human clinical trials showed that the robot-assisted has less drift compared to the manual operation with 41.07μm±20.78μm vs 299.66μm±85.84μm.The visual acuity with LogMAR of cases showed higher improvement in the robot-assisted group preliminary,which for manual of 0.78±0.44 vs robot-assisted 1.24±0.70 with no statistically significant difference.This study provides promising options for robot-assisted with very experienced surgeons in the most challenging microsurgery.The system has the potential to effectively reduce the training curve of doctors and alleviate the shortage of ophthalmic surgeons,which is very important for rural areas and underdeveloped countries.
