Takeshi Furuhashi

Control of Driving Torque Wave-form for Link Mechanisms

The driving torque of link mechanism generally varies with time, though periodically. it usually includes higher harmonic components. It is the purpose of this study to work out a method for obtaining specified driving torque wave-forms through redistributions of masses of links without changing motions of mechanisms. This paper presents a new technique of this method. The elimination of the higher order frequency components above the third order of the driving torque is tried on a crank-lever mechanism by using this technique. Calculated results are shown about specified torque wave-forms comprising up to the second order components or only the second order component. Experimental results on a mechanism with only the second order component are discussed and compared with the calculated results.

Control of joint forces in link mechanism.

The present paper is concerned with new technique for obtaining specified values of joint force at each pair through the redistribution of the mass of each link without changing the motion of a mechanism. The equations of joint force components acting at each joint are conveniently formulated to decide link mass parameters which satisfy the specified joint force values. As an example, the control method to turn the joint force locus to an elliptical locus is presented, and the joint force at the crank-pin joint of a crank lever mechanism is controlled by using the method. The effects of the control of the crank-pin joint force on the joint force at the lever-pin joint, the input torque, the shaking force and the shaking moment are also examined.