256
Biologically Inspired Robotics
Power Supply
FIGURE 13.13
Experimental setup for testing the multifunctional actuator.
500
600
700
800
900
1000
Speed (rpm)
1100
1200
1300
1400
1500
0
2
4
6
8
10
Current (A)
12
14
16
18
Speed
Current
20
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Torque (Nm)
FIGURE 13.14
Torque vs. current and speed in motor function.
For the brake function, the torque generated from the clutch/brake with
an interior inner coil is shown in Figure  13.16. The rotor was rotated at a
speed of 600 rpm and step current was applied to the inner coil gradually.
With the current augmented from 0 to 2.5 A, the measured torque increased
until it reached a maximum value of 0.48 Nm. Although the torque was
not sufficient to be applied to the human body directly, it is promising for
use in assistive knee braces with a transmission mechanism. As shown in