LIBRARY

PlanarMechanics.Distance

Measures the distance between the origins of two frame connectors.

This is a sensor component: it reads kinematic quantities without exerting forces or torques. The output is the scalar Euclidean distance between frame_a and frame_b origins. A small regularization parameter s_small prevents numerical issues when the distance approaches zero.

This component extends from PartialTwoFrameSensor This component extends from MultibodyComponents.Renderable

Usage

MultibodyComponents.PlanarMechanics.Distance(render=true, color=[0.5, 0.5, 0.5, 1.0], specular_coefficient=0.7, s_small=1e-10, arrow_diameter=0.03, z_position=0)

Parameters:

Name	Description	Units	Default value
render		–	true
color		–	[0.5, 0.5, 0.5, 1]
specular_coefficient		–	0.7
s_small	Small distance threshold for regularization	m	1e-10
arrow_diameter	Diameter of the visualization arrow	–	0.03
z_position	z-position of the arrow in animations	–	0

Connectors

• frame_a - Coordinate system (2-dim.) fixed to the component with one cut-force and cut-torque.

All variables are resolved in the planar world frame. (Frame2D)

• frame_b - Coordinate system (2-dim.) fixed to the component with one cut-force and cut-torque.

All variables are resolved in the planar world frame. (Frame2D)

• distance - This connector represents a real signal as an output from a component (RealOutput)

Variables

Name	Description	Units
L2	Squared distance	–
s_small2	Squared regularization threshold	–

Behavior

Dict{MIME{Symbol("text/plain")}, String} with 1 entry: MIME type text/plain => "Error displaying result"

Source

"""
Measures the distance between the origins of two frame connectors.

This is a sensor component: it reads kinematic quantities without exerting
forces or torques. The output is the scalar Euclidean distance between frame_a
and frame_b origins. A small regularization parameter `s_small` prevents
numerical issues when the distance approaches zero.
"""
component Distance
  extends PartialTwoFrameSensor
  extends MultibodyComponents.Renderable(color = [0.5, 0.5, 0.5, 1.0])
  "Scalar distance output"
  distance = RealOutput() {
    "Dyad": {
      "placement": {
        "diagram": {"iconName": "default", "x1": 450, "y1": 960, "x2": 550, "y2": 1060, "rot": 90}
      },
      "tags": []
    }
  }
  "Arrow visualization from frame_a to frame_b"
  arrow = MultibodyComponents.ArrowShape(render = render, color = color, head_at_origin = false, diameter = arrow_diameter)
  "Small distance threshold for regularization"
  parameter s_small::Length = 1e-10
  "Diameter of the visualization arrow"
  parameter arrow_diameter::Real = 0.03
  "z-position of the arrow in animations"
  parameter z_position::Real = 0
  "Squared distance"
  variable L2::Real
  "Squared regularization threshold"
  variable s_small2::Real
relations
  # Sensor: zero forces and torques
  frame_a.fx = 0
  frame_a.fy = 0
  frame_a.tau = 0
  frame_b.fx = 0
  frame_b.fy = 0
  frame_b.tau = 0
  # Squared distance
  L2 = (frame_b.x - frame_a.x) ^ 2 + (frame_b.y - frame_a.y) ^ 2
  s_small2 = s_small ^ 2
  # Smooth distance (regularized near zero)
  distance = ifelse(L2 > s_small2, sqrt(L2), L2 / (2 * s_small) + s_small / 2)
  # Arrow visualization from frame_a to frame_b
  arrow.r = [frame_a.x, frame_a.y, z_position]
  arrow.R = MultibodyComponents.RR(MultibodyComponents.nullrotation())
  arrow.r_shape = [0, 0, 0]
  arrow.length_direction = [frame_b.x - frame_a.x, frame_b.y - frame_a.y, 0]
  arrow.width_direction = [0, 0, 1]
  arrow.length = distance
  arrow.width = arrow_diameter
  arrow.height = arrow_diameter
metadata {
  "Dyad": {
    "icons": {"default": "dyad://MultibodyComponents/TwoFrameSensor.svg"},
    "labels": [{"label": "distance", "x": 500, "y": 680, "rot": 0}]
  }
}
end

Flattened Source

"""
Measures the distance between the origins of two frame connectors.

This is a sensor component: it reads kinematic quantities without exerting
forces or torques. The output is the scalar Euclidean distance between frame_a
and frame_b origins. A small regularization parameter `s_small` prevents
numerical issues when the distance approaches zero.
"""
component Distance
  frame_a = Frame2D() {
    "Dyad": {
      "placement": {
        "diagram": {"iconName": "default", "x1": 50, "y1": 450, "x2": 150, "y2": 550, "rot": 0}
      },
      "tags": []
    }
  }
  frame_b = Frame2D() {
    "Dyad": {
      "placement": {
        "diagram": {"iconName": "default", "x1": 850, "y1": 450, "x2": 950, "y2": 550, "rot": 0}
      },
      "tags": []
    }
  }
  parameter render::Boolean = true
  parameter color::Real[4] = [0.5, 0.5, 0.5, 1.0]
  parameter specular_coefficient::Real = 0.7
  "Scalar distance output"
  distance = RealOutput() {
    "Dyad": {
      "placement": {
        "diagram": {"iconName": "default", "x1": 450, "y1": 960, "x2": 550, "y2": 1060, "rot": 90}
      },
      "tags": []
    }
  }
  "Arrow visualization from frame_a to frame_b"
  arrow = MultibodyComponents.ArrowShape(render = render, color = color, head_at_origin = false, diameter = arrow_diameter)
  "Small distance threshold for regularization"
  parameter s_small::Length = 1e-10
  "Diameter of the visualization arrow"
  parameter arrow_diameter::Real = 0.03
  "z-position of the arrow in animations"
  parameter z_position::Real = 0
  "Squared distance"
  variable L2::Real
  "Squared regularization threshold"
  variable s_small2::Real
relations
  # Sensor: zero forces and torques
  frame_a.fx = 0
  frame_a.fy = 0
  frame_a.tau = 0
  frame_b.fx = 0
  frame_b.fy = 0
  frame_b.tau = 0
  # Squared distance
  L2 = (frame_b.x - frame_a.x) ^ 2 + (frame_b.y - frame_a.y) ^ 2
  s_small2 = s_small ^ 2
  # Smooth distance (regularized near zero)
  distance = ifelse(L2 > s_small2, sqrt(L2), L2 / (2 * s_small) + s_small / 2)
  # Arrow visualization from frame_a to frame_b
  arrow.r = [frame_a.x, frame_a.y, z_position]
  arrow.R = MultibodyComponents.RR(MultibodyComponents.nullrotation())
  arrow.r_shape = [0, 0, 0]
  arrow.length_direction = [frame_b.x - frame_a.x, frame_b.y - frame_a.y, 0]
  arrow.width_direction = [0, 0, 1]
  arrow.length = distance
  arrow.width = arrow_diameter
  arrow.height = arrow_diameter
metadata {
  "Dyad": {
    "icons": {"default": "dyad://MultibodyComponents/TwoFrameSensor.svg"},
    "labels": [{"label": "distance", "x": 500, "y": 680, "rot": 0}]
  }
}
end

Test Cases

No test cases defined.

Related

• Examples

• Experiments

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• Tests

  • SensorsTest