Caution: Pitch motor input:
±
24V, 5A peak, 3A continuous.
2.1.3 Propellers (Components #10)
The pitch and yaw propeller assemblies are composed of the actual propeller, which is directly mounted to the motor
shaft, and the aluminum propeller shield. The propellers used for both the pitch and yaw motors are Graupner
20/15 cm or 8/6''. The pitch motor/propeller has an identified thrust-force constant of 0.119 N/V and a thrust-torque
constant of 0.0036 N-m/V. The thrust-force constant describes the lifting force of propellers when working in the pitch
and roll axes. The thrust-torque constant is used to determine the amount of voltage needed to rotate the hover
system about its yaw axis.
Caution:
The propellers rotate at high speeds. Always make sure the propeller shields are installed when in
operation and stay clear of the system.
2.1.4 Encoders (Components #4 and #5)
The Quanser 3 DOF Hover experiment has three encoders used to measure the angle of pitch, yaw, and roll axes. In
quadrature mode, each encoder has a resolution of 8192 counts per revolution. Thus the effective position resolution
is 0.0439 degrees about the yaw, pitch, and roll axes.
2.2 System Specifications
The main parameters of the Quanser 3 DOF Hover is summarized in Table 2.2. The motor and encoder specifications
are listed in Table 2.3 below. Finally, Table 2.4 lists various dimensions, masses, and inertias of the Quanser 3 DOF
Hover system.
Symbol
Description
Value
Unit
K
t
Torque thrust constant of motor/propeller
0.0036
N-m/V
K
f
Force-thrust constant of motor/propeller
0.1188
N/V
L
Distance between pivot to each motor
0.197
cm
m
hover
Total moving mass of the system (body, four pro-
peller assemblies, etc.)
2.85
kg
J
y
Equivalent moment of inertia about yaw axis.
0.110
kg-m
2
J
p
Equivalent moment of inertia about pitch axis
0.0552
kg-m
2
J
r
Equivalent moment of inertia about roll axis.
0.0552
kg-m
2
Table 2.2: 3 DOF Hover model parameters
Symbol
Description
Value
Unit
R
m
Armature resistance of motor
0.83
Ω
K
t
Current-torque constant of motor
0.0182
N-m/A
J
m
Rotor moment of inertia of motor
1
.
91
×
10
−
6
kg-m
2
m
m
Mass of DC motor
0.292
kg
K
EC
Encoder resolution (in quadrature mode)
8192
counts/rev
Encoder sensitivity gain
7
.
67
×
10
−
4
rad/counts
Table 2.3: 3 DOF Hover motor and encoder specifications
3 DOF HOVER User Manual
v 1.0
