Frames

Frame(; name)

Frame is the fundamental 3D connector in the multibody library. Most components have one or several Frame connectors that can be connected together.

The Frame connector has internal variables for

• r_0: The position vector from the world frame to the frame origin, resolved in the world frame
• f: The cut force resolved in the connector frame
• tau: The cut torque resolved in the connector frame
• Depending on usage, also rotation and rotational velocity variables, accessed using ori(frame).R and ori(frame).w. The rotation matrix represents the rotation to rotate the world frame into the connector frame

Parameters

• render = false: If true, the connector is rendered in animations
• length = 1.0: Length of the frame when rendered
• radius = 0.1: Radius of the frame when rendered

PartialTwoFrames(;name)

Partial model with two frames

Connectors:

• frame_aFrame Coordinate system fixed to the component with one cut-force and cut-torque
• frame_bFrame Coordinate system fixed to the component with one cut-force and cut-torque

ZeroPosition(;name)

Set zero position vector and orientation object of frame_resolve

Connectors:

• frame_resolveFrameResolve Coordinate system fixed to the component with one cut-force and cut-torque

Frame(;name)

Coordinate system (2-dim.) fixed to the component with one cut-force and cut-torque. All variables are resolved in the planar world frame.

Variables:

• x: [m] x position
• y: [m] y position
• phi: [rad] rotation angle (counterclockwise)
• fx: [N] force in the x direction
• fy: [N] force in the y direction
• tau: [N.m] torque (clockwise)

Parameters:

• render: [Bool] Render the joint in animations
• length: [m] Length of each axis in animations
• radius: [m] Radius of each axis in animations