STUDY ON SAVING ENERGY FOR MECHATRONICS USING NOLINEAR CHARACTERISTICS

即使对于机械手和伺服系统等机电系统，减少能量的消耗对于改善由火力发电厂排放的CO_2气体变暖的地球环境也是重要的。因此，本课题对包含减速齿轮的位置控制系统的最优速度函数和最优传动比进行了研究，其中机电一体化系统的能量消耗由电机电枢阻引起的焦耳损失和齿轮引起的摩擦损失组成。首先，用齿轮的效率来表示减速齿轮的库仑摩擦，并给出动力学方程。从最优控制理论出发，得到了使能量消耗最小的最优电流和速度函数。对于减速齿轮由于库仑摩擦而产生的非线性，引入过零时间以求解析解。通过仿真研究了系统各参数对最优过零时间的影响。最后，利用最优速度函数进行了位置控制实验。将最优速度函数耗散的能量与梯形速度函数耗散的能量进行了比较。实验和仿真结果表明，最优速度函数可以在较大的负载转动惯量下提供显着的节能效果，能量的耗散还依赖于功率变送器的传动比，如齿轮和滚珠丝杠。耗散的能量由传动比、发射机效率和负载来表示。以能量消耗最小为目标，通过数值计算和解析法得到了齿轮和滚珠丝杠的传动比。与传统的惯性匹配方法相比，得到的最优传动比可以降低系统的耗能。

It is important to reduce the dissipated energy even for mechatronic systems such as manipulators and servo systems for improving the environment of the earth that is warmed up by CO_2 gas emitted from thermal power plants. Hence, this project has studied on optimal velocity functions and optimal gear ratios that minimize the dissipated energy in a position control system including reduction gears.The energy dissipated in the mechatronic systems is composed of Joule loss due to motor armature resistances and friction loss due to gears. First, Coulomb friction of a reduction gear is represented using efficiency of the gear and the dynamic equation is expressed. Te optimal current and velocity functions that minimize the dissipated energy are obtained from optimal control theory. For nonlinearity due to the Coulomb friction of a reduction gear, the zero crossing time is introduced in order to obtain analytical solutions. The effect of each parameter of the system on the optimal zero crossing time is investigated by simulation. Finally, an experiment on position control is performed using the optimal velocity functions. The energy dissipated with the optimal velocity function is compared to the energy dissipated with a trapezoidal velocity function. The results of the experiment and simulations indicate that the optimal velocity function can provide remarkable energy saving for a larger moment of load inertia.The dissipated energy also depends on a transmission ratio of power transmitter such as gears and ball-screws. The dissipated energy is expressed by a transmission ratio, efficiency of the transmitter and load. In order to minimize the dissipated energy, the transmission ratios of gears and ball-screws are obtained by numerically and analytically. The obtained optimal transmission ratios can reduce the dissipated energy compare to the conventional inertia matching method.