enforce_limits.cpp

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/*      Title     : enforce_limits.cpp
 *      Project   : moveit_servo
 *      Created   : 7/5/2021
 *      Author    : Brian O'Neil, Andy Zelenak, Blake Anderson, Tyler Weaver
 */
 
#include <Eigen/Core>
#include <sensor_msgs/msg/joint_state.hpp>
 
#include <moveit/robot_model/joint_model_group.h>
#include <moveit_servo/enforce_limits.hpp>
 
namespace moveit_servo
{
namespace
{
double getVelocityScalingFactor(const moveit::core::JointModelGroup* joint_model_group, const Eigen::VectorXd& velocity)
{
  std::size_t joint_delta_index{ 0 };
  double velocity_scaling_factor{ 1.0 };
  for (const moveit::core::JointModel* joint : joint_model_group->getActiveJointModels())
  {
    const auto& bounds = joint->getVariableBounds(joint->getName());
    if (bounds.velocity_bounded_ && velocity(joint_delta_index) != 0.0)
    {
      const double unbounded_velocity = velocity(joint_delta_index);
      // Clamp each joint velocity to a joint specific [min_velocity, max_velocity] range.
      const auto bounded_velocity = std::min(std::max(unbounded_velocity, bounds.min_velocity_), bounds.max_velocity_);
      velocity_scaling_factor = std::min(velocity_scaling_factor, bounded_velocity / unbounded_velocity);
    }
    ++joint_delta_index;
  }
 
  return velocity_scaling_factor;
}
 
}  // namespace
 
void enforceVelocityLimits(const moveit::core::JointModelGroup* joint_model_group, const double publish_period,
                           sensor_msgs::msg::JointState& joint_state, const double override_velocity_scaling_factor)
{
  // Get the velocity scaling factor
  Eigen::VectorXd velocity =
      Eigen::Map<Eigen::VectorXd, Eigen::Unaligned>(joint_state.velocity.data(), joint_state.velocity.size());
  double velocity_scaling_factor = override_velocity_scaling_factor;
  // if the override velocity scaling factor is approximately zero then the user is not overriding the value.
  if (override_velocity_scaling_factor < 0.01)
    velocity_scaling_factor = getVelocityScalingFactor(joint_model_group, velocity);
 
  // Take a smaller step if the velocity scaling factor is less than 1
  if (velocity_scaling_factor < 1)
  {
    Eigen::VectorXd velocity_residuals = (1 - velocity_scaling_factor) * velocity;
    Eigen::VectorXd positions =
        Eigen::Map<Eigen::VectorXd, Eigen::Unaligned>(joint_state.position.data(), joint_state.position.size());
    positions -= velocity_residuals * publish_period;
 
    velocity *= velocity_scaling_factor;
    // Back to sensor_msgs type
    joint_state.velocity = std::vector<double>(velocity.data(), velocity.data() + velocity.size());
    joint_state.position = std::vector<double>(positions.data(), positions.data() + positions.size());
  }
}
 
}  // namespace moveit_servo