I am working on multiple simulations with the pr2 model in ros and gazebo. I was able to find how to define the starting pose of the pr2 model by modifying the pr2nocontrollers.launch file, replacing $(optenv ROBOT_INITIAL_POSE) with commands like these : -x -0.5 -J torso_lift_joint 0.3 -J r_wrist_flex_joint -0.7 generated with a python script from positions saved thanks to this command rostopic echo -n 1 joint_states > starting_pose.yaml and it works well... Except for the grippers, which I want to be opened. To be more precise, the commands include lines like this one -J r_gripper_l_finger_joint 0.18, which are supposed to be the "open pose" of the gripper, and when I start the pr2 model with the new launch file, the pose is right, but the grippers are closed.

Is my method wrong ? Can someone help me with starting the pr2 model with open grippers ?