5.4.3.2 robot:move

robot:move {axis} {position} (#:time {time}) (#:speed {speed}) (#:placement {’spatial|’relative|’absolute}) (’counter)

This procedure is entirely compatible with the Level 2 robot:move command, but adds an extra key movement-type argument which causes the position argument to be interpreted in different ways. This means that programs written against the Level 2 API will work identically if they use the Level 3 API.

Because of the nature of Scheme procedure definitions, if you want to specify a movement-type you must also specify time and speed parameters; if you want default behaviour with regard to these you can give their values as #f.

• axis this should be a symbol from the set {’base ’shoulder ’elbow ’wrist-rotate ’wrist ’grip}, and indicates the axis to move.
• position this is the position to move the motor, in units of degrees. Zero degrees corresponds in all cases to the mid position, and motors will typically turn through +/- 90° though some are more restricted. The exact meaning depends on the value of movement-type, but if this is not present then the position is the absolution position to which the motor will turn.
• time is the time in seconds in which the motion will take place.
• speed is the maximum speed in microsteps per second that will be applied to the motors. A default value will be used if #f is given here.
• movement-type specifies how exactly the position request should be enacted. The options are the symbols (equivalent strings are not permitted)
  • ’absolute, which will simply move the motor to the requested position; this is the default if the parameter is not present
  • ’space, which only works when axis is either ’wrist or ’elbow, and places those joints into positions fixed in space; in both cases 0° corresponds to the components being horizontal (parallel to the supporting plane), and increased angles correspond to upward movements
  • ’relative, which will add the position value to the current position (as determined by the last move command) of the axis, and then move the axis to that position
  • ’parallel, which works exactly as ’relative except in the special case of axis as ’shoulder, in which case the elbow will simultaneously move contrary to the shoulder movement, or the case of axis as ’elbow in which case the wrist will move contrary to the elbow.

Examples

Before you do anything with the Level 3 API, you need to instantiate a robot object to represent the device, and then you need to park it to ensure it is in a well-known initial state:

Now you can make the robot do things. To get the forearm horizontal (in two seconds),

and the wrist

Now move the shoulder forward 30°, keeping the entire forearm horizontal,

And when you’re finished playing, don’t forget to put the robot back into the neutral position, so that it will be well-behaved when it starts up again

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