|
Study on the
collision-mechanical properties of tomatoes gripped by
harvesting robot fingers
Li Zhi-Guo*, Liu
Ji-Zhan, Li Ping-Ping and Yin Jian-Jun
Institute of Agricultural Engineering, Jiangsu University,
Zhenjiang 212013, China.
*Corresponding author. E-mail:
lizhiguo0821@126.com.
Accepted 6 November, 2009 |
|
The data of collision-mechanical property of tomatoes
gripped by robot fingers are important for the gripping
control of tomato harvesting robot. In the study, tests of
controlling the fingers to grip tomatoes were conducted to
ascertain the effects of input current, motor speed and
impact positions on the impact force of fingers and maximum
deformation of tomatoes. The input current of the motor
ranged from 1200 to 2100 mA, the motor speed from 25 to 3000
rpm and the three impact positions as follows, 1 (radial
arm), 2 (sloping at an angle of
22.5° to the radial arm) and 3 (sloping
at an angle of 45° to the radial arm). The results
shown that under the condition of the same motor speed and
input current, the peak impact force on the radial arm,
compared with other impact positions, was maximum, the
deformation of tomato was the smallest and the degree of
mechanical damage was the lowest too. Under different speed
and input current conditions, when the fingers grip the
tomato on the radial arm, the peak force of fingers and the
maximum deformation of tomatoes were highly influenced by
the motor speed and input current, especially the input
current. The peak impact force and the maximum deformation
of the tomato increased respectively with increase in the
motor speed and input current and these followed cubic
polynomial regression equations.
Key words:
Harvesting robot, fingers, mechanical properties, collision,
tomato. |
