Absolute circular move

The way Absolute moves an axis group is "position." You decide the position your group moves to. The starting point is the group's current position, and the end point is the target position. The target position is counted from the origin in the specified coordinate system. Since it is a circular move, an axis group is moving along a circular path.

Functions

MoveCircularAbsolute: moves an axis group to an absolute position along a circular path.

GetAGroupPosition: gets and displays the set and actual positions of a group. For further details, see Get and set group values.

MoveCircularAbsolute

MoveCircularAbsolute moves an axis group from the starting point to end point along a circular path. The group stops after it reaches the end point.

Starting point: this is where your group is now.

Auxpoint: the point that defines a circular path.

Endpoint: the target position your group will reach.

Notice the following parameters:

• CircMode: specifies the meaning of the input signal AuxPoint. See the McCircMode type.
• Length: the length of the AuxPoint and EndPoint arrays.
• AuxPoint: the absolute positions that define a circular path for each axis in the group. It is an array. For further details, see Circular motion modes.
• EndPoint: the absolute target positions (end points) for each axis in the group. It is an array.
• PathChoice: choice of path. See the McCircPathChoice type. For more information about the short and long paths, see Circular motion modes -> mcRadius.
• BufferMode: defines how to blend the velocity of two functions. See the McBufferMode type. For details, see Chapter 5: Single-Axis Motion > Motion states -> Common parameters.
• TransitionMode: inserts a transition curve to blend the path. If you want to perform a sequence of movements smoothly, you need to use this parameter. In KS 4.2, KINGSTAR supports only velocity blending for MoveCircular functions. See the McTransitionMode type.

BufferMode and TransitionMode are relevant to blending. For more information about blending, see Blend movements.

Code

When you make a circular move, you can choose to use blending or not. We demonstrate this function without blending. For more information about a blending sample, see Blending for group motion.

In this sample, we use mcRadius to make a circular move. In GroupMotion.cpp, add the following code:

VOID MoveCircularAbsoluteGroup(int Group)
{
    RtPrintf("Make circular absolute group move.\n\n");

    const int LENGTH = 3;   //The length of the Position array.
    double AuxPoints[LENGTH] = { -400, 0, 0 };
    double EndPoints[LENGTH] = { 0, -400, 400 };

    /*We lower the velocity to 360 because the end positions are not far. If the velocity is high
      and the distance is short, the axis will brake sharply. This may damage the axis.*/
    KsCommandStatus absCircMove = WaitForCommand(30, TRUE, MoveCircularAbsolute(Group, mcRadius,
        LENGTH, AuxPoints, EndPoints, mcShortPath, 360, 3600, 3600, 360000, mcAxisCoordSystem,
        mcAborting, mcNone, NULL));
    if (absCircMove.Error)
        RtPrintf("MoveCircularAbsolute failed: %d\n\n", absCircMove.ErrorId);

    //Wait a few cycles to get the correct end positions.
    Sleep(5);

    //Display the end positions.
    RtPrintf("End positions:\n\n");
    GetAGroupPosition(Group);
}

Output: