Joystick Dead Band
This is the narrow band around the centre of the control lever where no command is produced despite movement. Vibration, the lever not seating exactly at centre, and sensor noise all stay inside this band. It is typically kept at 3–10% of full stroke; if it is too narrow you get unintended movement, if it is too wide the control feels unresponsive.
The dead band is implemented in software: the control board reads the joystick signal and holds the output at zero unless the threshold around the neutral value is exceeded. In a tractor cab, engine and ground vibration constantly move the lever by a few degrees; without a dead band the implement would make millimetric movements on its own and the motor would run for nothing.
- Very narrow dead band: the lever generating commands by itself while travelling in the field, drawing unnecessary current.
- Very wide dead band: the first part of the operator's push on the lever is wasted and the control feels like it "responds late".
- Drift: on a potentiometer joystick the neutral point can drift over time; the dead band then behaves asymmetrically and unintended movement starts in one direction.
On proportional controls the dead band is designed together with the initial part of the response curve. When the field complaint "the lever moves slightly without anyone touching it" comes in, the joystick neutral point and cable connection are checked first, then supply stability.
The context in which this term is used: Converting a tractor hydraulic lever to electronic control