Analysis of Adaptability of Manipulator for Grasping Apple by Cable-Driven Pneumatic Pressure

Abstract

To sort different sizes of apples, a kind of passive grab cable-driven of flexible manipulator is designed. Each finger consists two single degree-of-freedom joints and a torsional spring is installed on each joint. The two-point of finger is stretched by a cable, which is connected to pistonstem of cy- linder. However, when the cable looses,the torsional spring drive the finger bend and grab the apple. The objective function is determined by the minimum change range of grasping force, Which can be optimized by the fmincon-function provided by the software MATLAB. We can conclude that: twist the stiffness of hydropneumatic spring arek2 andk3 ,preloaded angle areΦ02 andΦ03, moreover it show that the manipulator has a good supple adaptation without causing damage to apple.

Self-adaption grasping force analysis for an apple sorting hand-claw with robustness

“…The displacement and pressure at this moment are 0.8980 rad and 0.2220 MPa respectively according to Eq. (12). Beyond 0.2220 MPa hinge 2 will touch the air-cylinder.…”

“…The series double hinges cannot crash into the air-cylinder, namely D 1 and D 2 calculated by Eqs. (12) and (13) are greater than half of the radial length of the air-cylinder. 3. θ 1b , θ 2b cannot be negative when grasping the biggest apple.…”

“…A flexible finger with plate-spring skeleton and artificial muscle actuator applied in multi-joint manipulator is reported, 11 and an apple grasping manipulator driven by cable has also been designed. 12 Based on our previous research, this paper is focused on studying a flexible hand-claw with series double hinges driven by air-cylinders. By optimizing the structure, sizes and parameters of torsion springs, the two torsion springs exhibit a coordinative function to enhance the flexibility of hand-claw.…”