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| Joysticks have been showing up in concept cars for half a century give or take a decade. And very early cars used tillers, the mechanical joy stick for steering.
But I don't think joysticks will ever be used for cars, trucks, or tractors and combines. Here's why.
Take a car/truck with a 14" steering wheel and 4 turns lock to lock. That's 44" circumference on the wheel and a total of 176 inches of motion lock to lock. And for good highway driving (interstates) we can lay a hand on a knee and drive all day with hardly more than finger motion using maybe 4 inches ouf of that 176 inches. Yes, I know some cars have quicker steering and that quicker steering lets the driver flinch and turn them sideways. Its easy to find tracks from that on any highway. If you have a joy stick with 4" motion at the tip to go lock to lock and the control is linear you need that same portion of the control range most of the time 4" x 4 / 176 = .09" 1/11th inch of motion. About the thickness of a pencil lead before its sharpened or thin spaghetti affter its cooked. Holding a hand that steady for hours would lead mine to be cramped. If the control range was set to be speed sensitive, then the driver would lapse into a bang-bang control mode flopping the joy stick to the extremes and would miss driveways at very slow speeds from over steering. Some places put poles along side driveways, or put them along side buildings and retaining walls. Cars and poles or walls don't mix, the car looses. Watch kids on a driving simulator plow out the road periphery.
It gets worse for tractors. Where the car/truck may be 6 to 8' wide and be driving down a 12 to 14' wide lane giving room for at least 6' of lateral motion, driving a cultivator tractor may have 2" each way from cutting out the crop, 4" from running over the crop with the tractor wheels. Sprayers are a little more tolerant, maybe 8 or 9" from running over the crop.
And that's just the lateral motion of the joystick. In a car or truck, cruise control would help though swishing the joystick front to rear would be OK for speed control. In a tractor we tend to want a constant speed from the beginning to the end of a row. Say cultivating 3/4 mile rows at 2.5 mph. That's a constant speed for 18 minutes at a time. Not something to be held with a variable control, we depend on setting a hand throttle and ignoring it for that amount of time.
Then there's more to driving the tractor and combine than just steering and speed. The implements need to be controlled. If its a semimounted plow, theres each end to raise and lower, independently for square ended fields. Front first, rear a second or two later. Then engine power to bring up when the plow is down, and differential lock to engage. At the end, engine power to slack off, front to raise, then rear, diffferential lock to release and that turn at the end. Maybe if the passes are far apart, there might even be a gear to shift to speed up across the headland. And those hydraulic motions want to be smooth, not yanks else the plow breaks. For me tractor driving is a two handed plus a foot or two job. Maybe my equipment is old, but its less complex than the more modern stuff I see at the shows.
Working the tractor/combine is a whole lot more than just direction and speed. If it wasn't, the automated tractor would be common. Even the best of automatic steering still takes a driver to run the implement and turn around at the ends of the rows and to watch out for fences. If a driver can only run the joystick for speed and direction what is to do all the other tasks or is the driver only out for a "joy ride?"
Gerald J.
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Joysticks
