message: FIX: Also apply forces in correct direction for "opening" grasps
diff: @@ -138,7 +138,7 @@ void FrankaGripperSim::update(const ros::Time& now, const ros::Duration& period)
  w1_d = this->finger2_.getPosition();
  w2_d = this->finger1_.getPosition();
  std::lock_guard<std::mutex> lock(this->mutex_);
  - f_d = -this->config_.force_desired / 2.0;
  + f_d = this->config_.force_desired / 2.0;
  }
  control(this->finger1_, this->pid1_, w1_d, 0.5 * dw_d, f_d, period);
  @@ -382,9 +382,10 @@ void FrankaGripperSim::onGraspGoal(const franka_gripper::GraspGoalConstPtr& goal
  }
  double width = this->finger1_.getPosition() + this->finger2_.getPosition();
  + float direction = std::copysign(1.0, goal->width - width);
  transition(State::GRASPING, Config{.width_desired = goal->width < width ? 0 : kMaxFingerWidth,
  .speed_desired = goal->speed,
  - .force_desired = goal->force,
  + .force_desired = direction * goal->force,
  .tolerance = goal->epsilon});
  waitUntilStateChange();
  