评价20%精草铵膦铵盐可溶液剂对非耕地杂草的防除效果。于杂草生长盛期采用茎叶喷雾法进行田间小区试验。试验药剂20%精草铵膦铵盐可溶液剂剂量为300~600 g a.i./hm^(2)时,对非耕地禾本科杂草和阔叶杂草均有较好的防效,药后20 d,总草株...评价20%精草铵膦铵盐可溶液剂对非耕地杂草的防除效果。于杂草生长盛期采用茎叶喷雾法进行田间小区试验。试验药剂20%精草铵膦铵盐可溶液剂剂量为300~600 g a.i./hm^(2)时,对非耕地禾本科杂草和阔叶杂草均有较好的防效,药后20 d,总草株防效和鲜重防效分别为93.32%~97.69%、97.69%~99.53%;对照药剂20%精草铵膦铵盐可溶液剂在450 g a.i./hm^(2)剂量时的总草株防效和鲜重防效分别为95.14%、98.52%。20%精草铵膦铵盐可溶液剂可以有效防除非耕地杂草,推荐剂量300~600 g a.i./hm^(2)。展开更多
Most existing force feedback methods are still difficult to meet the requirements of real-time force calculation in virtual assembly and operation with complex objects. In addition, there is often an assumption that t...Most existing force feedback methods are still difficult to meet the requirements of real-time force calculation in virtual assembly and operation with complex objects. In addition, there is often an assumption that the controlled objects are completely flee and the target object is only completely fixed or flee, thus, the dynamics of the kinematic chain where the controlled objects are located are neglected during the physical simulation of the product manipulation with force feedback interaction. This paper proposes a physical simulation method of product assembly and operation manipulation based on statistically learned contact force prediction model and the coupling of force feedback and dynamics. In the proposed method, based on hidden Markov model （HMM） and local weighting learning （LWL）, contact force prediction model is constructed, which can estimate the contact force in real time during interaction. Based on computational load balance model, the computing resources are dynamically assigned and the dynamics integral step is optimized. In addition, smoothing process is performed to the force feedback on the synchronization points. Consequently, we can solve the coupling and synchronization problems of high-frequency feedback force servo. low-frequency dynamics solver servo and scene rendering servo, and realize highly stable and accurate force feedback in the physical simulation of product assembly and operation manipulation. This research proposes a physical simulation method of product assembly and operation manipulation.展开更多
文摘评价20%精草铵膦铵盐可溶液剂对非耕地杂草的防除效果。于杂草生长盛期采用茎叶喷雾法进行田间小区试验。试验药剂20%精草铵膦铵盐可溶液剂剂量为300~600 g a.i./hm^(2)时,对非耕地禾本科杂草和阔叶杂草均有较好的防效,药后20 d,总草株防效和鲜重防效分别为93.32%~97.69%、97.69%~99.53%;对照药剂20%精草铵膦铵盐可溶液剂在450 g a.i./hm^(2)剂量时的总草株防效和鲜重防效分别为95.14%、98.52%。20%精草铵膦铵盐可溶液剂可以有效防除非耕地杂草,推荐剂量300~600 g a.i./hm^(2)。
基金Supported by National Natural Science Foundation of China(51475418)National Basic Research 973 Program of China(2011CB706503)Science Fund for Creative Research Groups of National Natural Science Foundation of China(51221004)
文摘Most existing force feedback methods are still difficult to meet the requirements of real-time force calculation in virtual assembly and operation with complex objects. In addition, there is often an assumption that the controlled objects are completely flee and the target object is only completely fixed or flee, thus, the dynamics of the kinematic chain where the controlled objects are located are neglected during the physical simulation of the product manipulation with force feedback interaction. This paper proposes a physical simulation method of product assembly and operation manipulation based on statistically learned contact force prediction model and the coupling of force feedback and dynamics. In the proposed method, based on hidden Markov model （HMM） and local weighting learning （LWL）, contact force prediction model is constructed, which can estimate the contact force in real time during interaction. Based on computational load balance model, the computing resources are dynamically assigned and the dynamics integral step is optimized. In addition, smoothing process is performed to the force feedback on the synchronization points. Consequently, we can solve the coupling and synchronization problems of high-frequency feedback force servo. low-frequency dynamics solver servo and scene rendering servo, and realize highly stable and accurate force feedback in the physical simulation of product assembly and operation manipulation. This research proposes a physical simulation method of product assembly and operation manipulation.
