PVC Pipe Depalletizing
This example demonstrates how to use Tzara, the Telekinesis Physical AI Agent, to build a depalletizing pipeline. Tzara generates code that picks PVC pipes arranged in a grid on a table and drops them into a paper packaging box. Placement inside the box is unstructured — the robot simply drops each pipe rather than placing it precisely.
Demo
UR10e picking PVC pipes from a grid and dropping into a packaging box
The Natural Language Instruction
On my table i have multiple pvc pipes sorted in grid structure. I need to pick them and place into paper packaging box. Placing does not have to be structured, you can just drop them. Add logging at each step.The Generated Code
python
# Depalletizing pipeline: UR10e + OnRobot RG6
# Picks PVC pipes from a flat grid on a table and drops them into a packaging box.
# Drop placement is unstructured — no precise in-box positioning required.
import math
from loguru import logger
from telekinesis.synapse.robots.manipulators.universal_robots import UniversalRobotsUR10E
from telekinesis.synapse.tools.parallel_grippers.onrobot import OnRobotRG6
# ============================================================
# Constants
# ============================================================
ROBOT_IP = "192.168.1.2"
GRIPPER_IP = "192.168.1.1"
GRIPPER_PROTOCOL = "MODBUS_TCP"
# Pick grid layout
PICK_GRID_ROWS = 4
PICK_GRID_COLS = 5
PICK_ORIGIN_XYZ = [0.050, 0.820, 0.195] # base frame position of grid slot (0, 0) in meters
PICK_ROW_PITCH = -0.070 # row spacing along Y (m)
PICK_COL_PITCH = 0.070 # column spacing along X (m)
# Pick orientation: TCP pointing straight down
PICK_RPY_DEG = [180.0, 0.0, 90.0]
# Z levels (meters)
Z_APPROACH = 0.320 # safe clearance height above the table
Z_PICK = PICK_ORIGIN_XYZ[2] # contact height (same for all grid slots)
# Drop pose: a single fixed pose above the packaging box
DROP_POSE = [-0.350, 0.750, 0.320, 180.0, 0.0, 90.0]
# Gripper settings (mm / N)
GRIPPER_OPEN_MM = 70.0
GRIPPER_CLOSE_MM = 18.0
GRIPPER_FORCE_N = 50.0
# Motion parameters
CART_SPEED = 0.50 # m/s
CART_ACCEL = 0.70 # m/s^2
# Home joint pose (degrees)
HOME_JOINT_DEG = [90.0, -90.0, -90.0, -90.0, 90.0, 0.0]
JOINT_SPEED_DEG = 45.0
JOINT_ACCEL_DEG = 90.0
# ============================================================
# Helper functions
# ============================================================
def generate_pick_poses():
"""Return a list of pick poses [x, y, z, rx, ry, rz] for every grid slot."""
poses = []
for r in range(PICK_GRID_ROWS):
for c in range(PICK_GRID_COLS):
x = PICK_ORIGIN_XYZ[0] + c * PICK_COL_PITCH
y = PICK_ORIGIN_XYZ[1] + r * PICK_ROW_PITCH
z = Z_PICK
poses.append([x, y, z] + list(PICK_RPY_DEG))
logger.debug(f"Generated {len(poses)} pick poses ({PICK_GRID_ROWS} rows x {PICK_GRID_COLS} cols)")
return poses
def _approach(pose, z_safe):
"""Return a copy of pose with z replaced by z_safe."""
p = list(pose)
p[2] = z_safe
return p
def pick_part(robot, gripper, pick_pose, index):
"""Execute pick sequence for a single PVC pipe."""
approach = _approach(pick_pose, Z_APPROACH)
logger.info(f"[Part {index}] Moving to pick approach")
logger.debug(f" approach = {approach}")
robot.set_cartesian_pose(approach, speed=CART_SPEED, acceleration=CART_ACCEL)
logger.success(f"[Part {index}] At pick approach")
logger.info(f"[Part {index}] Opening gripper")
gripper.move(position=GRIPPER_OPEN_MM, force=GRIPPER_FORCE_N)
logger.success(f"[Part {index}] Gripper open")
logger.info(f"[Part {index}] Descending to pick pose")
logger.debug(f" pick pose = {pick_pose}")
robot.set_cartesian_pose(pick_pose, speed=CART_SPEED, acceleration=CART_ACCEL)
logger.success(f"[Part {index}] At pick pose")
logger.info(f"[Part {index}] Closing gripper to grasp pipe")
gripper.move(position=GRIPPER_CLOSE_MM, force=GRIPPER_FORCE_N)
logger.success(f"[Part {index}] Pipe grasped")
logger.info(f"[Part {index}] Retreating from pick")
robot.set_cartesian_pose(approach, speed=CART_SPEED, acceleration=CART_ACCEL)
logger.success(f"[Part {index}] Retreated from pick")
def drop_part(robot, gripper, index):
"""Move to the fixed drop pose above the box and release the pipe."""
logger.info(f"[Part {index}] Moving to drop pose above packaging box")
logger.debug(f" drop pose = {DROP_POSE}")
robot.set_cartesian_pose(DROP_POSE, speed=CART_SPEED, acceleration=CART_ACCEL)
logger.success(f"[Part {index}] At drop pose")
logger.info(f"[Part {index}] Opening gripper to drop pipe")
gripper.move(position=GRIPPER_OPEN_MM, force=GRIPPER_FORCE_N)
logger.success(f"[Part {index}] Pipe dropped into box")
def run_pipeline(robot, gripper):
"""Iterate the pick grid and drop every pipe into the packaging box."""
pick_poses = generate_pick_poses()
n_parts = len(pick_poses)
logger.info(f"Starting depalletizing pipeline: {n_parts} pipes to process")
logger.info("Moving to home pose before starting")
robot.set_joint_positions(HOME_JOINT_DEG, speed=JOINT_SPEED_DEG, acceleration=JOINT_ACCEL_DEG)
logger.success("At home pose")
for i, pick_pose in enumerate(pick_poses):
logger.info(f"===== Pipe {i + 1} / {n_parts} =====")
pick_part(robot, gripper, pick_pose, i + 1)
drop_part(robot, gripper, i + 1)
logger.success(f"===== Pipe {i + 1} complete =====")
logger.info("All pipes processed — returning to home pose")
robot.set_joint_positions(HOME_JOINT_DEG, speed=JOINT_SPEED_DEG, acceleration=JOINT_ACCEL_DEG)
logger.success("Pipeline complete")
# ============================================================
# Main
# ============================================================
def main():
robot = UniversalRobotsUR10E()
gripper = OnRobotRG6()
robot_connected = False
gripper_connected = False
try:
logger.info(f"Connecting to UR10e at {ROBOT_IP}")
robot.connect(ROBOT_IP)
robot_connected = True
logger.success("Robot connected")
logger.info(f"Connecting to OnRobot RG6 at {GRIPPER_IP} via {GRIPPER_PROTOCOL}")
gripper.connect(ip=GRIPPER_IP, protocol=GRIPPER_PROTOCOL)
gripper_connected = True
logger.success("Gripper connected")
run_pipeline(robot, gripper)
except Exception as e:
logger.exception(f"Pipeline failed: {type(e).__name__}: {e}")
finally:
if gripper_connected:
try:
logger.info("Disconnecting gripper")
gripper.disconnect()
except Exception as e:
logger.warning(f"Gripper disconnect failed: {e}")
if robot_connected:
try:
logger.info("Disconnecting robot")
robot.disconnect()
except Exception as e:
logger.warning(f"Robot disconnect failed: {e}")
logger.info("Cleanup complete")
if __name__ == "__main__":
main()