MT
Unwanted small direction signals can be caused by a small analog offset signal when
a switched joystick outputs "zero". These small direction signals can cause the
powerchair to veer slightly.
Intended
direction
Actual
direction
Veer
Small direction signals can cause a slight veer
With a proportional joystick the user can correct for any veer by moving the joystick
slightly sideways. A switched joystick does not have this capability.
If RJM has Analog Joystick has the value 'No', the UCM ignores the small speed and
direction signals generated by the joystick processing. This makes sure that the
powerchair does not veer.
The size of the "zero"-area is determined by the value of the
Neutral Maximum
parameter (see
5.3.9.3)
zero F-R
zero F-R
zero L-R
zero L-R
Neutral
Maximum
10%
zero
zero
F-R
zero
L-R
Neutral
Maximum
30%
zero
Neutral
Maximum
10%
RJM has Analog Joystick: Yes RJM has Analog Joystick: No
zero
L-R
zero
F-R
Note:
1. Setting RJM has Analog Joystick to 'No' can also help users who
have problems to steer straight ahead.
2. Veer can also occur if the performance of the two drive motors is
not equal. See section
95
4.3.2.5: Veer Compensation