V5 uses the amount of joystick movement to represent the amount of velocity in a direction, and there is a conversion formula between velocity and movement to represent the linear relationship between them. Here is the speed formula.
speed = speedLevel * maximum speed * actual movement / maximum movement (660)
speedLevel is the parameter used to limit the speed variation and it takes values in the range of (0.1]. When speedLevel is 0.1, the speed range that the joystick can control is one tenth of the actual speed. Its default value is 1.
The maximum speed varies from direction to direction. The speed ranges for each direction are listed below.
The speed range in the vertical direction is [-6,6] (m/s).
The speed range for head rotation is [-100,100] (deg/sec).
The speed range in the horizontal direction is [-23,23] in meters/second.