Page 281 - Flexible Robotics in Medicine

Flexible robotic platform with multiple-bending tendon-driven mechanism 271

Figure 12.1
Flexible manipulator unit diagram.

Figure 12.2
Flexible manipulator unit (left) driven by motor unit (right).

12.2.1.2 Motor unit module

Referring to the motor module designed by Olivera, Chen, and Hunter [4], the authors engaged
the use of a worm gear and a DC motor. Precise calibration is conducted to achieve the perfect
configuration required to actuate the flexible tip, which is costly to manufacture.

Our proposed motor unit module has a more straightforward concept, which is less costly
and simpler to fabricate. The motor unit comprises only stepper motors, as it is more
advantageous as compared to DC motors since its precision can be easily controlled and
varied, they are easier to set up and simpler to control. The motor unit module is shown in
Fig. 12.2, which consists of eight stepper motors with each stepper motor attached to one
tendon string that will manipulate the movement of the flexible tip.

Each stepper motor module in the motor unit is designed like the flexible manipulator
module, whereby the stabilizer is attached to the module, preventing any rotational
movement that will affect the pulling of the tendon wires.