Instrumentation & Measurement Magazine 26-2 - 52

Fig. 4. (a) The experimental platform for measuring the adhesion area. (b) The adhesion area under different control methods. (c) The binary image of adhesion
area under different control methods.
increase, and the body of the robot will rotate around the l-axis
passing point C. The adhesion limbs A and C will be subjected
to the adhesion forces FvA
and FvD
can be decomposed into FvAx2, FvAz and FvDx
. On the x-axis and z-axis, it
, FvDz, respectively.
The force analysis of the robot as a whole can be obtained:
12





Oy    ) L (   
M FF F )L (   
F F F )W
M FF F A
(
(
v x vx v x
B A
O AA B
M F F Fq
q
v
z
q
v x12 v x
vAx
B
v zv z
v z vz
v x qx vx
v z
q z
q
Fx     O DDC    0
FF F F F F F
Oz A A C B D D
A
x
q x
q zv zq
z      0
From Σ Fz=0, the force of FvBx
and FvDz
     
F F F F F F Fv x
qAA B D D C
v zq zv z
v x
the algebraic sum of the forces in other directions, and L2
than the algebraic sum of other forces. So, ΣM Ox
in the x-axis direction is less than
>L1
in the z-axis direction is also smaller
<0 , and the
x     1 D D C 2
(
1 CD D 2
F F F )L
F F F ) L
(3)
accelerate to rotate to l, which will cause the robot to fall due to
the failure of adhesion. A is the farthest from the axis of rotation
and has the greatest probability of adhesion failure. In order
to solve the above problem, it is necessary to use a mechanical
control strategy to adjust the position of the rotating shaft l.
The most ideal position of the rotation axis of the body of the
robot is on the connection line between the limbs A and C of the
over-stance phase. At this time, the limbs A and C will not stick
and tear due to the displacement in the z-axis direction, and the
position of the center of mass is also in the z-direction. It will not
change due to the rotation of the body of the robot, so it will not
cause the robot to fall due to the increase of the overturning moment.
The adjusted force of the robot on the outer arc surface is
shown in Fig. 4b. To achieve the desired effect, the vector sum of
the vertical component forces FqA
and FvAz
,
the body of the robot will rotate clockwise on the y-axis. The algebraic
sum of FqA
body of the robot will move clockwise around the x-axis. Likewise,
the algebraic sum of the FqDz
algebraic sum of the other forces on the z-axis. So, ΣM Ox
and FvAzforces is less than the
<0, and
the body will rotate clockwise around the z-axis. The rotation
around the z-axis and the x-axis is the same as the rotation direction
of the center of mass around the l-axis, so the body will
52
is 0. The situation of the two forces FqAz
and FvDz
at the A limb in Fig. 4a
at the C limb is
the same as at the A limb. In order for the robot not to be affected
by these two forces, the application point of the force should be
in the opposite direction of the AD limb connection, and because
the limbs ABCD of the stance phase are coplanar at four points.
After determining the directions of the above two forces,
the magnitudes of these two forces do not need to be accurately
determined. The two forces are set to 0 before the movement
starts, and the value collected by the sensor in the z-axis direction
is used as feedback to continuously adjust the magnitude
IEEE Instrumentation & Measurement Magazine
April 2023

Instrumentation & Measurement Magazine 26-2

Table of Contents for the Digital Edition of Instrumentation & Measurement Magazine 26-2