To evaluate the operator health risk exposed to whole-body vibration(WBV) while the electric-shovel loads the ore on the truck body, the semi-truck mathematical model and 3-D virtual prototype were built to simulate t...To evaluate the operator health risk exposed to whole-body vibration(WBV) while the electric-shovel loads the ore on the truck body, the semi-truck mathematical model and 3-D virtual prototype were built to simulate the high shockwave of truck cab under the shovel loading. Discrete element method was utilized to accurately estimate the impacting force on the truck body. Based on the ISO 2631-5 criteria, the Sed is about 0.56 MPa in both models, which means that the dump operators have a high probability of adverse health effects over long-term exposure to these vibrations. The 4-DOF operator model was built to investigate the biodynamic response of seated-human body exposed to WBV in terms of the transmission of vibrations through the body. The results show that the response peak is in the frequency range of 4-6 Hz corresponding to the primary body resonant frequency.展开更多
Aiming at the requirements of intelligent loading and shipping in large household appliance industry,an automatic loading and unloading robot for refrigerator is proposed.The robot is a gantry truss robot,which is com...Aiming at the requirements of intelligent loading and shipping in large household appliance industry,an automatic loading and unloading robot for refrigerator is proposed.The robot is a gantry truss robot,which is composed of active support,passive support,beam and fixture components at both ends to realize the taking and placing of the refrigerator on the logistics transmission line to the truck.In the actual working conditions,the no-load truss robot experiment,found that the robot in the design problems,and the robot was optimized.It not only solves the safety hazards of the refrigerator when grabbing and stacking products,but also realizes the automation and intelligence of the refrigerator conveying process.展开更多
Wood transportation begins from the landing or the forest road where the processed wood assortments are placed, they are loaded on trucks and then transported to the wood-working industry and/or the consumption center...Wood transportation begins from the landing or the forest road where the processed wood assortments are placed, they are loaded on trucks and then transported to the wood-working industry and/or the consumption centers. Wood transportation in Greece is carried out, almost exclusively, by trucks. The aim of this study is to analyze the evolution of timber trucking in Greece through the analysis of wood transportation waybills. A total of 1,471 waybills have been collected and analyzed that cover the period 1981-2008 from nine of the most productive and representative forest districts in Greece, in terms of timber production. The final dataset included information on the type and technical characteristics of truck types, the transported wood quantities and haulage distances. Furthermore, data on the wood transportation cost for the year 2010 have been collected and analyzed. According to the results, the number of two-axle trucks that dominated in the 1980s is reducing rapidly, mostly to the benefit of larger three-axle and four-axle trucks. More than three quarters （77%） of wood transportation is conducted in the period June-October. Mean vehicle load per vehicle type differs between conifer and broadleaved species from 7.1% up to 23.9%. Transportation of stacked wood with semitrailers is conducted with overloaded trucks, which could entail serious problems for public safety and the condition of road network. New design standards will enhance serviceability of the wood transportation routes and environmental protection.展开更多
基金Project(2006BAB11B03)supported by the National Key Technology Research and Development Program of ChinaProject(Z1011030055010004)supported by Beijing Municipal Science Program of China
文摘To evaluate the operator health risk exposed to whole-body vibration(WBV) while the electric-shovel loads the ore on the truck body, the semi-truck mathematical model and 3-D virtual prototype were built to simulate the high shockwave of truck cab under the shovel loading. Discrete element method was utilized to accurately estimate the impacting force on the truck body. Based on the ISO 2631-5 criteria, the Sed is about 0.56 MPa in both models, which means that the dump operators have a high probability of adverse health effects over long-term exposure to these vibrations. The 4-DOF operator model was built to investigate the biodynamic response of seated-human body exposed to WBV in terms of the transmission of vibrations through the body. The results show that the response peak is in the frequency range of 4-6 Hz corresponding to the primary body resonant frequency.
文摘Aiming at the requirements of intelligent loading and shipping in large household appliance industry,an automatic loading and unloading robot for refrigerator is proposed.The robot is a gantry truss robot,which is composed of active support,passive support,beam and fixture components at both ends to realize the taking and placing of the refrigerator on the logistics transmission line to the truck.In the actual working conditions,the no-load truss robot experiment,found that the robot in the design problems,and the robot was optimized.It not only solves the safety hazards of the refrigerator when grabbing and stacking products,but also realizes the automation and intelligence of the refrigerator conveying process.
文摘Wood transportation begins from the landing or the forest road where the processed wood assortments are placed, they are loaded on trucks and then transported to the wood-working industry and/or the consumption centers. Wood transportation in Greece is carried out, almost exclusively, by trucks. The aim of this study is to analyze the evolution of timber trucking in Greece through the analysis of wood transportation waybills. A total of 1,471 waybills have been collected and analyzed that cover the period 1981-2008 from nine of the most productive and representative forest districts in Greece, in terms of timber production. The final dataset included information on the type and technical characteristics of truck types, the transported wood quantities and haulage distances. Furthermore, data on the wood transportation cost for the year 2010 have been collected and analyzed. According to the results, the number of two-axle trucks that dominated in the 1980s is reducing rapidly, mostly to the benefit of larger three-axle and four-axle trucks. More than three quarters （77%） of wood transportation is conducted in the period June-October. Mean vehicle load per vehicle type differs between conifer and broadleaved species from 7.1% up to 23.9%. Transportation of stacked wood with semitrailers is conducted with overloaded trucks, which could entail serious problems for public safety and the condition of road network. New design standards will enhance serviceability of the wood transportation routes and environmental protection.
