Use keyboard to control input force (Ramp)

Is there a way to use a keyboard up/down key to control the input force value of a prismatic joint?

Answer 1

[Riya]

Hello Zeeshan,

As per my understanding you want to use keyboard to control input force.

Please note that you can achieve this by using the `KeyPressFcn` and `KeyReleaseFcn` callback functions in MATLAB.

Here's an example code that demonstrates how you can implement this functionality:

function controlPrismaticJoint() 
% Create a prismatic joint 
joint = rigidBodyJoint('prismatic'); 

% Set the initial force and step size 
force = 0; 
stepSize = 0.1; 

% Create a figure window and set the callback functions 
fig = figure; 
set(fig, 'KeyPressFcn', @keyPressCallback, 'KeyReleaseFcn', @keyReleaseCallback); 

while ishghandle(fig) 
    % Set the input force value of the prismatic joint 
    joint.Position = force; 
    
    % Perform other computations or simulations 
    
    % Pause to allow time for the callbacks to execute 
    pause(0.01); 
end 

% Key press callback function 
    function keyPressCallback(~, event) 
        if strcmp(event.Key, 'uparrow') 
            % Increase the force value 
            force = force + stepSize; 
        elseif strcmp(event.Key, 'downarrow') 
            % Decrease the force value 
            force = force - stepSize; 
        end 
    end 

% Key release callback function 
    function keyReleaseCallback(~, event) 
        if strcmp(event.Key, 'uparrow') || strcmp(event.Key, 'downarrow') 
            % Stop changing the force value when the key is released 
            force = 0; 
        end 
    end 
end 

In this code, the `KeyPressFcn` callback function is triggered when a key is pressed, and the `KeyReleaseFcn` callback function is triggered when a key is released.

Inside these functions, you can check which key was pressed/released using the `event.Key` property and modify the `force` variable accordingly.

Note that this code is just an example, and you may need to adapt it to your specific use case or integrate it into your existing MATLAB code.

Hope it helps.