rs_opw_kinematics::kinematic_traits

Trait Kinematics

Source 
pub trait Kinematics: Send + Sync {
    // Required methods
    fn inverse(&self, pose: &Pose) -> Solutions;
    fn inverse_continuing(&self, pose: &Pose, previous: &Joints) -> Solutions;
    fn forward(&self, qs: &Joints) -> Pose;
    fn inverse_5dof(&self, pose: &Pose, j6: f64) -> Solutions;
    fn inverse_continuing_5dof(&self, pose: &Pose, prev: &Joints) -> Solutions;
    fn constraints(&self) -> &Option<Constraints>;
    fn kinematic_singularity(&self, qs: &Joints) -> Option<Singularity>;
    fn forward_with_joint_poses(&self, joints: &Joints) -> [Pose; 6];
}
Expand description

Defines agreed functionality of direct and inverse kinematics and singularity detection.

Required Methods§

Source

fn inverse(&self, pose: &Pose) -> Solutions

Find inverse kinematics (joint position) for this pose This function is faster but does not handle the singularity J5 = 0 well. All returned solutions are cross-checked with forward kinematics and valid.

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fn inverse_continuing(&self, pose: &Pose, previous: &Joints) -> Solutions

Find inverse kinematics (joint position) for this pose This function handles the singularity J5 = 0 by keeping the previous values the values J4 and J6 from the previous solution Use CONSTRAINT_CENTERED as previous if there is no previous position but we prefer to be as close to the center of constraints (or zeroes if not set) as possible.

Source

fn forward(&self, qs: &Joints) -> Pose

Find forward kinematics (pose from joint positions). For 5 DOF robot, the rotation of the joint 6 should normally be 0.0 but some other value can be given, meaning the tool is mounted with fixed rotation offset.

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fn inverse_5dof(&self, pose: &Pose, j6: f64) -> Solutions

Calculates the inverse kinematics for a robot while ignoring the rotation around joint 6. The position of the tool center point remains precise, but the rotation is approximate (rotation around the tool axis is ignored). The return value for joint 6 is set according to the provided parameter. This method is significantly faster

Source

fn inverse_continuing_5dof(&self, pose: &Pose, prev: &Joints) -> Solutions

Calculates the inverse kinematics for a robot while ignoring the rotation around joint 6. The position of the tool center point remains precise, but the rotation is approximate (rotation around the tool axis is ignored). The return value for joint 6 is set based on the previous joint values. This method is significantly faster

Source

fn constraints(&self) -> &Option<Constraints>

Returns constraints under what the solver is operating. Constraints are remembered here and can be used for generating random joint angles needed by RRT, or say providing limits of sliders in GUI.

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fn kinematic_singularity(&self, qs: &Joints) -> Option<Singularity>

Detect the singularity. Returns either A type singlularity or None if no singularity detected.

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fn forward_with_joint_poses(&self, joints: &Joints) -> [Pose; 6]

Computes the forward kinematics for a 6-DOF robotic arm and returns an array of poses representing the position and orientation of each joint, including the final end-effector.

The function calculates the transformation for each joint in the robotic arm using the joint angles (in radians) and the kinematic parameters of the robot (link lengths and offsets). It returns an array of 6 poses: one for each joint and the end-effector.

§Parameters
  • self: A reference to the kinematics model containing the geometric and joint-specific parameters.
  • joints: A reference to an array of joint angles (in radians) for the 6 joints of the robot.
§Returns
  • An array of 6 Pose structures:
    • Pose 1: The position and orientation of the base link.
    • Pose 2: The position and orientation of link 1 (first joint).
    • Pose 3: The position and orientation of link 2 (second joint).
    • Pose 4: The position and orientation of link 3 (third joint).
    • Pose 5: The position and orientation of link 4 (fourth joint), before applying any wrist offset.
    • Pose 6: The position and orientation of the end-effector, including the wrist offset (c4).
§Example
use rs_opw_kinematics::kinematic_traits::Kinematics;
use rs_opw_kinematics::kinematics_impl::OPWKinematics;
use rs_opw_kinematics::parameters::opw_kinematics::Parameters;
let parameters = Parameters {
    a1: 0.150,
    a2: 0.000,
    b: 0.000,
    c1: 0.550,
    c2: 0.550,
    c3: 0.600,
    c4: 0.110,
    offsets: [0.0; 6],  // No joint offsets
    ..Parameters::new()
};

let joints = [0.0, 0.0, 0.0, 0.0, 0.0, 0.0];  // All joints straight up
let kinematics = OPWKinematics::new(parameters);

let poses = kinematics.forward_with_joint_poses(&joints);

assert_eq!(poses.len(), 6);  // Should return 6 poses
§Notes
  • The function applies the geometric parameters (like link lengths and joint offsets) and computes each joint’s position and orientation relative to the base frame.
  • The final pose (Pose 6) includes the c4 offset, which accounts for the wrist length.

Implementors§