We consider the problem of inducing withdrawal reflex on a test subject by exposing the subject’s skin to an electromagnetic beam. Heat-sensitive nociceptors in the skin are activated wherever the temperature is abov...We consider the problem of inducing withdrawal reflex on a test subject by exposing the subject’s skin to an electromagnetic beam. Heat-sensitive nociceptors in the skin are activated wherever the temperature is above the activation temperature. Withdrawal reflex occurs when the activated volume reaches a threshold. We non-dimensionalize the problem to write the temperature as the product of a parameter-free function of non-dimensional variables and a function of beam parameters. This formulation allows studying beam parameters without knowing skin material parameters. We examine the effects of spot size, total power and distribution type of the electromagnetic beam on 3 quantities at reflex: 1) the time to reflex, 2) the maximum temperature increase, and 3) the total energy consumption. We find that the flat-top beam is the best, with the lowest energy consumption and the smallest maximum temperature increase. The Super-Gaussian beam is only slightly inferior to the flat-top. The Gaussian beam has by far the worst performance among these three.展开更多
Modern rotating machines,which are represented by high-end grinding machines,have developed toward high precision,intelligence,and high durability in recent years.As the core components of grinding machine spindles,gr...Modern rotating machines,which are represented by high-end grinding machines,have developed toward high precision,intelligence,and high durability in recent years.As the core components of grinding machine spindles,grinding wheels greatly affect the vibration level during operation.The unbalance vibration self-recovery regulation(UVSRR)system is proposed to suppress the vibration of grinding wheels during workpiece processing,eliminating or minimizing the imbalance.First,technical principles and the system composition are introduced.Second,the balancing actuator in the UVSRR system is analyzed in detail.The advanced nature of the improved structure is presented through structure introduction and advantage analysis.The performance of the balancing actuator is mutually verified by the theoretical calculation of torque and software simulation.Results show that the self-locking torque satisfies the actual demand,and the driving torque is increased by 1.73 times compared with the traditional structure.Finally,the engineering application value of the UVSRR system is verified by laboratory performance comparison and actual factory application.The balancing speed and effect of the UVSRR system are better than those of an international mainstream product and,the quality of the workpieces machined in the factory improved by 40%.展开更多
文摘We consider the problem of inducing withdrawal reflex on a test subject by exposing the subject’s skin to an electromagnetic beam. Heat-sensitive nociceptors in the skin are activated wherever the temperature is above the activation temperature. Withdrawal reflex occurs when the activated volume reaches a threshold. We non-dimensionalize the problem to write the temperature as the product of a parameter-free function of non-dimensional variables and a function of beam parameters. This formulation allows studying beam parameters without knowing skin material parameters. We examine the effects of spot size, total power and distribution type of the electromagnetic beam on 3 quantities at reflex: 1) the time to reflex, 2) the maximum temperature increase, and 3) the total energy consumption. We find that the flat-top beam is the best, with the lowest energy consumption and the smallest maximum temperature increase. The Super-Gaussian beam is only slightly inferior to the flat-top. The Gaussian beam has by far the worst performance among these three.
基金supported by the National Natural Science Foundation of China(Grant No.51875031)the Natural Science Foundation of Beijing,China(Grant No.3212010).
文摘Modern rotating machines,which are represented by high-end grinding machines,have developed toward high precision,intelligence,and high durability in recent years.As the core components of grinding machine spindles,grinding wheels greatly affect the vibration level during operation.The unbalance vibration self-recovery regulation(UVSRR)system is proposed to suppress the vibration of grinding wheels during workpiece processing,eliminating or minimizing the imbalance.First,technical principles and the system composition are introduced.Second,the balancing actuator in the UVSRR system is analyzed in detail.The advanced nature of the improved structure is presented through structure introduction and advantage analysis.The performance of the balancing actuator is mutually verified by the theoretical calculation of torque and software simulation.Results show that the self-locking torque satisfies the actual demand,and the driving torque is increased by 1.73 times compared with the traditional structure.Finally,the engineering application value of the UVSRR system is verified by laboratory performance comparison and actual factory application.The balancing speed and effect of the UVSRR system are better than those of an international mainstream product and,the quality of the workpieces machined in the factory improved by 40%.
