Biomedical Engineering Reference
In-Depth Information
Table 11.1
The linear actuator specifications
Specifications
PQ-12
Stroke
20 mm
6 N at 15 mm s -1
Rated force
7 N at 13 mm s -1
Max power point
27 mm s -1
Max speed
Current draw
250 mA
Input voltage
5 V dc
2 k linear potentiometer
Feedback mode
Feedback potentiometer linearity
1%
Mass
75 g
10 to +50 C
Operating temperature
Actuator lifetime
100 000 cycles
Flexible substrate with
printed semi-conductor
Spacer opening
Vent
Spacer adhesive
Active area
Flexible substrate with printed
interdigitating electrodes
Tail
Figure 11.4
The structure of the sensor and its different components
To experimentally determine the force - conductance relationship for the FSR, several
standard weights are placed on the active area and its conductance is measured. The
conductance versus force data is plotted in Figure 11.5. The data plotted in Figure 11.5
show that the conductance in FSR is almost linearly related to the applied force.
Fitting a line on the experimental data, the following equation can be used to relate the
conductance ( C ) and force ( F ).
C
=
a.F
+
b
(11.1)
Best fit using least squares method resulted in values of a = 0.079 and b = 0.016.
To find the resistance of the FSR, we used the electric circuit shown in Figure 11.6.
 
Search WWH ::




Custom Search