When you design the layout of control panel that combines both physical controls like buttons, joysticks and touch- or touchless screen with digital HMI, it is important to consider some human factors, mentioned below.
Avoiding obstructions
This is probably one of the most important factors, that will define the layout.
If the user interacts with the touch-screen, place joysticks and other protruding controls away from the touchscreen so they do not obstruct usage and cannot be accidentally touched by the user. Sometimes it is useful to position the display higher, making it protrude above the control panel surface with other controls.
Also it is important that when you interact with physical controls and get the feedback from the indicators (both physical, like 7-segment displays, and digital, like on-screen labels and widgets), the arm or fingers don’t close them.
It means, that the preferred position of physical controls is at the left or right side of the display, or if they are positioned closer to the user. But it can also depend on the usage frequency — if touch screen is operated more often, it must be closer.
Logical grouping
All the physical controls must be grouped logically and support usage flow — first actions on top or left side, next actions below or to the right, same as with digital UIs.
Safe distance
The distance between knobs or joysticks or other controls must leave sufficient space for fingers. If the controls are sensitive to small interactions (by intention, or if the selection of hardware components is limited), it also protects from accident interactions.