Files
lerobot/lerobot/common/robot_devices/motors/feetech.py

753 lines
26 KiB
Python

import enum
import time
import traceback
from copy import deepcopy
import numpy as np
import tqdm
from lerobot.common.robot_devices.motors.configs import FeetechMotorsBusConfig
from lerobot.common.robot_devices.utils import RobotDeviceAlreadyConnectedError, RobotDeviceNotConnectedError
from lerobot.common.utils.utils import capture_timestamp_utc
PROTOCOL_VERSION = 0
BAUDRATE = 1_000_000
TIMEOUT_MS = 1000
MAX_ID_RANGE = 252
# For joints in percentage (i.e. joints that move linearly like the prismatic joint of a gripper),
# their nominal range is [0, 100] %. For instance, for Aloha gripper, 0% is fully
# closed, and 100% is fully open. To account for slight calibration issue, we allow up to
# [-10, 110] until an error is raised.
LOWER_BOUND_LINEAR = -10
UPPER_BOUND_LINEAR = 110
HALF_TURN_DEGREE = 180
# See this link for STS3215 Memory Table:
# https://docs.google.com/spreadsheets/d/1GVs7W1VS1PqdhA1nW-abeyAHhTUxKUdR/edit?usp=sharing&ouid=116566590112741600240&rtpof=true&sd=true
# data_name: (address, size_byte)
SCS_SERIES_CONTROL_TABLE = {
"Model": (3, 2),
"ID": (5, 1),
"Baud_Rate": (6, 1),
"Return_Delay": (7, 1),
"Response_Status_Level": (8, 1),
"Min_Angle_Limit": (9, 2),
"Max_Angle_Limit": (11, 2),
"Max_Temperature_Limit": (13, 1),
"Max_Voltage_Limit": (14, 1),
"Min_Voltage_Limit": (15, 1),
"Max_Torque_Limit": (16, 2),
"Phase": (18, 1),
"Unloading_Condition": (19, 1),
"LED_Alarm_Condition": (20, 1),
"P_Coefficient": (21, 1),
"D_Coefficient": (22, 1),
"I_Coefficient": (23, 1),
"Minimum_Startup_Force": (24, 2),
"CW_Dead_Zone": (26, 1),
"CCW_Dead_Zone": (27, 1),
"Protection_Current": (28, 2),
"Angular_Resolution": (30, 1),
"Offset": (31, 2),
"Mode": (33, 1),
"Protective_Torque": (34, 1),
"Protection_Time": (35, 1),
"Overload_Torque": (36, 1),
"Speed_closed_loop_P_proportional_coefficient": (37, 1),
"Over_Current_Protection_Time": (38, 1),
"Velocity_closed_loop_I_integral_coefficient": (39, 1),
"Torque_Enable": (40, 1),
"Acceleration": (41, 1),
"Goal_Position": (42, 2),
"Goal_Time": (44, 2),
"Goal_Speed": (46, 2),
"Torque_Limit": (48, 2),
"Lock": (55, 1),
"Present_Position": (56, 2),
"Present_Speed": (58, 2),
"Present_Load": (60, 2),
"Present_Voltage": (62, 1),
"Present_Temperature": (63, 1),
"Status": (65, 1),
"Moving": (66, 1),
"Present_Current": (69, 2),
# Not in the Memory Table
"Maximum_Acceleration": (85, 2),
}
SCS_SERIES_BAUDRATE_TABLE = {
0: 1_000_000,
1: 500_000,
2: 250_000,
3: 128_000,
4: 115_200,
5: 57_600,
6: 38_400,
7: 19_200,
}
CALIBRATION_REQUIRED = ["Goal_Position", "Present_Position"]
MODEL_CONTROL_TABLE = {
"scs_series": SCS_SERIES_CONTROL_TABLE,
"sts3215": SCS_SERIES_CONTROL_TABLE,
}
MODEL_RESOLUTION = {
"scs_series": 4096,
"sts3215": 4096,
}
MODEL_BAUDRATE_TABLE = {
"scs_series": SCS_SERIES_BAUDRATE_TABLE,
"sts3215": SCS_SERIES_BAUDRATE_TABLE,
}
# High number of retries is needed for feetech compared to dynamixel motors.
NUM_READ_RETRY = 20
NUM_WRITE_RETRY = 20
def convert_ticks_to_degrees(ticks, model):
resolutions = MODEL_RESOLUTION[model]
# Convert the ticks to degrees
return ticks * (360.0/resolutions)
def convert_degrees_to_ticks(degrees, model):
resolutions = MODEL_RESOLUTION[model]
# Convert degrees to motor ticks
return int(degrees * (resolutions/360.0))
def adjusted_to_homing_ticks(
raw_motor_ticks: int, encoder_offset: int, model: str, motorbus, motor_id: int
) -> int:
"""
Shifts raw [0..4095] ticks by an encoder offset, modulo a single turn [0..4095].
"""
# Retrieve previous values for tracking
prev_value = motorbus.previous_value[motor_id - 1]
multi_turn_index = motorbus.multi_turn_index[motor_id - 1]
resolutions = MODEL_RESOLUTION[model]
# Add offset and wrap within resolution
shifted = (raw_motor_ticks + encoder_offset) % resolutions
# # Re-center into a symmetric range (e.g., [-2048, 2047] if resolutions==4096) Thus the middle homing position will be virtual 0.
if shifted > resolutions // 2:
shifted -= resolutions
# Update multi turn values if needed
if prev_value is not None:
delta = shifted - prev_value
# If jump forward > 180° (2048 steps), assume full rotation
if delta > (resolutions // 2):
multi_turn_index -= 1
elif delta < (-resolutions // 2):
multi_turn_index += 1
motorbus.previous_value[motor_id - 1] = shifted
motorbus.multi_turn_index[motor_id - 1] = multi_turn_index
# Apply the multi turn to output so we can track beyong -180..180 degrees or -2048..2048 ticks
ticks = shifted + (multi_turn_index * resolutions)
# Update direction of rotation of the motor to match between leader and follower.
# In fact, the motor of the leader for a given joint can be assembled in an
# opposite direction in term of rotation than the motor of the follower on the same joint.
drive_mode = 0
if motorbus.calibration is not None:
drive_mode = motorbus.calibration["drive_mode"][motor_id - 1]
if drive_mode:
ticks *= -1
return ticks
def adjusted_to_motor_ticks(
adjusted_pos: int, encoder_offset: int, model: str, motorbus, motor_id: int
) -> int:
"""
Inverse of adjusted_to_homing_ticks().
Converts homed servo ticks (with multi-turn indexing) back to [0..4095].
"""
multi_turn_index = motorbus.multi_turn_index[motor_id - 1]
resolutions = MODEL_RESOLUTION[model]
# Remove offset and wrap within resolution
shifted = (adjusted_pos - encoder_offset) % resolutions
# Apply the multi turn to output ticks because goal position can have input of -32000...32000
ticks = shifted + (multi_turn_index * resolutions)
# Update direction of rotation of the motor to match between leader and follower.
# In fact, the motor of the leader for a given joint can be assembled in an
# opposite direction in term of rotation than the motor of the follower on the same joint.
drive_mode = 0
if motorbus.calibration is not None:
drive_mode = motorbus.calibration["drive_mode"][motor_id - 1]
if drive_mode:
ticks *= -1
return ticks
def convert_to_bytes(value, bytes, mock=False):
if mock:
return value
import scservo_sdk as scs
# Note: No need to convert back into unsigned int, since this byte preprocessing
# already handles it for us.
if bytes == 1:
data = [
scs.SCS_LOBYTE(scs.SCS_LOWORD(value)),
]
elif bytes == 2:
data = [
scs.SCS_LOBYTE(scs.SCS_LOWORD(value)),
scs.SCS_HIBYTE(scs.SCS_LOWORD(value)),
]
elif bytes == 4:
data = [
scs.SCS_LOBYTE(scs.SCS_LOWORD(value)),
scs.SCS_HIBYTE(scs.SCS_LOWORD(value)),
scs.SCS_LOBYTE(scs.SCS_HIWORD(value)),
scs.SCS_HIBYTE(scs.SCS_HIWORD(value)),
]
else:
raise NotImplementedError(
f"Value of the number of bytes to be sent is expected to be in [1, 2, 4], but "
f"{bytes} is provided instead."
)
return data
def get_group_sync_key(data_name, motor_names):
group_key = f"{data_name}_" + "_".join(motor_names)
return group_key
def get_result_name(fn_name, data_name, motor_names):
group_key = get_group_sync_key(data_name, motor_names)
rslt_name = f"{fn_name}_{group_key}"
return rslt_name
def get_queue_name(fn_name, data_name, motor_names):
group_key = get_group_sync_key(data_name, motor_names)
queue_name = f"{fn_name}_{group_key}"
return queue_name
def get_log_name(var_name, fn_name, data_name, motor_names):
group_key = get_group_sync_key(data_name, motor_names)
log_name = f"{var_name}_{fn_name}_{group_key}"
return log_name
def assert_same_address(model_ctrl_table, motor_models, data_name):
all_addr = []
all_bytes = []
for model in motor_models:
addr, bytes = model_ctrl_table[model][data_name]
all_addr.append(addr)
all_bytes.append(bytes)
if len(set(all_addr)) != 1:
raise NotImplementedError(
f"At least two motor models use a different address for `data_name`='{data_name}' ({list(zip(motor_models, all_addr, strict=False))}). Contact a LeRobot maintainer."
)
if len(set(all_bytes)) != 1:
raise NotImplementedError(
f"At least two motor models use a different bytes representation for `data_name`='{data_name}' ({list(zip(motor_models, all_bytes, strict=False))}). Contact a LeRobot maintainer."
)
class TorqueMode(enum.Enum):
ENABLED = 1
DISABLED = 0
class DriveMode(enum.Enum):
NON_INVERTED = 0
INVERTED = 1
class CalibrationMode(enum.Enum):
# Joints with rotational motions are expressed in degrees in nominal range of [-180, 180]
DEGREE = 0
# Joints with linear motions (like gripper of Aloha) are experessed in nominal range of [0, 100]
LINEAR = 1
class JointOutOfRangeError(Exception):
def __init__(self, message="Joint is out of range"):
self.message = message
super().__init__(self.message)
class FeetechMotorsBus:
"""
The FeetechMotorsBus class allows to efficiently read and write to the attached motors. It relies on
the python feetech sdk to communicate with the motors. For more info, see the [feetech SDK Documentation](https://emanual.robotis.com/docs/en/software/feetech/feetech_sdk/sample_code/python_read_write_protocol_2_0/#python-read-write-protocol-20).
A FeetechMotorsBus instance requires a port (e.g. `FeetechMotorsBus(port="/dev/tty.usbmodem575E0031751"`)).
To find the port, you can run our utility script:
```bash
python lerobot/scripts/find_motors_bus_port.py
>>> Finding all available ports for the MotorsBus.
>>> ['/dev/tty.usbmodem575E0032081', '/dev/tty.usbmodem575E0031751']
>>> Remove the usb cable from your FeetechMotorsBus and press Enter when done.
>>> The port of this FeetechMotorsBus is /dev/tty.usbmodem575E0031751.
>>> Reconnect the usb cable.
```
Example of usage for 1 motor connected to the bus:
```python
motor_name = "gripper"
motor_index = 6
motor_model = "sts3215"
config = FeetechMotorsBusConfig(
port="/dev/tty.usbmodem575E0031751",
motors={motor_name: (motor_index, motor_model)},
)
motors_bus = FeetechMotorsBus(config)
motors_bus.connect()
position = motors_bus.read("Present_Position")
# move from a few motor steps as an example
few_steps = 30
motors_bus.write("Goal_Position", position + few_steps)
# when done, consider disconnecting
motors_bus.disconnect()
```
"""
def __init__(
self,
config: FeetechMotorsBusConfig,
):
self.port = config.port
self.motors = config.motors
self.mock = config.mock
self.model_ctrl_table = deepcopy(MODEL_CONTROL_TABLE)
self.model_resolution = deepcopy(MODEL_RESOLUTION)
self.port_handler = None
self.packet_handler = None
self.calibration = None
self.is_connected = False
self.group_readers = {}
self.group_writers = {}
self.logs = {}
self.multi_turn_index = self.multi_turn_index = [0] * len(self.motors)
self.previous_value = self.previous_value = [0] * len(self.motors)
def connect(self):
if self.is_connected:
raise RobotDeviceAlreadyConnectedError(
f"FeetechMotorsBus({self.port}) is already connected. Do not call `motors_bus.connect()` twice."
)
if self.mock:
import tests.mock_scservo_sdk as scs
else:
import scservo_sdk as scs
self.port_handler = scs.PortHandler(self.port)
self.packet_handler = scs.PacketHandler(PROTOCOL_VERSION)
try:
if not self.port_handler.openPort():
raise OSError(f"Failed to open port '{self.port}'.")
except Exception:
traceback.print_exc()
print(
"\nTry running `python lerobot/scripts/find_motors_bus_port.py` to make sure you are using the correct port.\n"
)
raise
# Allow to read and write
self.is_connected = True
self.port_handler.setPacketTimeoutMillis(TIMEOUT_MS)
def reconnect(self):
if self.mock:
import tests.mock_scservo_sdk as scs
else:
import scservo_sdk as scs
self.port_handler = scs.PortHandler(self.port)
self.packet_handler = scs.PacketHandler(PROTOCOL_VERSION)
if not self.port_handler.openPort():
raise OSError(f"Failed to open port '{self.port}'.")
self.is_connected = True
def are_motors_configured(self):
# Only check the motor indices and not baudrate, since if the motor baudrates are incorrect,
# a ConnectionError will be raised anyway.
try:
return (self.motor_indices == self.read("ID")).all()
except ConnectionError as e:
print(e)
return False
def find_motor_indices(self, possible_ids=None, num_retry=2):
if possible_ids is None:
possible_ids = range(MAX_ID_RANGE)
indices = []
for idx in tqdm.tqdm(possible_ids):
try:
present_idx = self.read_with_motor_ids(self.motor_models, [idx], "ID", num_retry=num_retry)[0]
except ConnectionError:
continue
if idx != present_idx:
# sanity check
raise OSError(
"Motor index used to communicate through the bus is not the same as the one present in the motor memory. The motor memory might be damaged."
)
indices.append(idx)
return indices
def set_bus_baudrate(self, baudrate):
present_bus_baudrate = self.port_handler.getBaudRate()
if present_bus_baudrate != baudrate:
print(f"Setting bus baud rate to {baudrate}. Previously {present_bus_baudrate}.")
self.port_handler.setBaudRate(baudrate)
if self.port_handler.getBaudRate() != baudrate:
raise OSError("Failed to write bus baud rate.")
@property
def motor_names(self) -> list[str]:
return list(self.motors.keys())
@property
def motor_models(self) -> list[str]:
return [model for _, model in self.motors.values()]
@property
def motor_indices(self) -> list[int]:
return [idx for idx, _ in self.motors.values()]
def set_calibration(self, calibration: dict[str, list]):
self.calibration = calibration
def apply_calibration(self, values: np.ndarray | list, motor_names: list[str] | None):
if motor_names is None:
motor_names = self.motor_names
# Convert from unsigned int32 original range [0, 2**32] to signed float32 range
values = values.astype(np.float32)
for i, name in enumerate(motor_names):
calib_idx = self.calibration["motor_names"].index(name)
calib_mode = self.calibration["calib_mode"][calib_idx]
if CalibrationMode[calib_mode] == CalibrationMode.DEGREE:
homing_offset = self.calibration["homing_offset"][calib_idx]
motor_idx, model = self.motors[name]
# Convert raw motor ticks to homed ticks, then convert the homed ticks to degrees
values[i] = adjusted_to_homing_ticks(values[i], homing_offset, model, self, motor_idx)
values[i] = convert_ticks_to_degrees(values[i], model)
elif CalibrationMode[calib_mode] == CalibrationMode.LINEAR:
start_pos = self.calibration["start_pos"][calib_idx]
end_pos = self.calibration["end_pos"][calib_idx]
# Rescale the present position to a nominal range [0, 100] %,
# useful for joints with linear motions like Aloha gripper
values[i] = (values[i] - start_pos) / (end_pos - start_pos) * 100
if (values[i] < LOWER_BOUND_LINEAR) or (values[i] > UPPER_BOUND_LINEAR):
raise JointOutOfRangeError(
f"Wrong motor position range detected for {name}. "
f"Expected to be in nominal range of [0, 100] % (a full linear translation), "
f"with a maximum range of [{LOWER_BOUND_LINEAR}, {UPPER_BOUND_LINEAR}] % to account for some imprecision during calibration, "
f"but present value is {values[i]} %. "
"This might be due to a cable connection issue creating an artificial jump in motor values. "
"You need to recalibrate by running: `python lerobot/scripts/control_robot.py calibrate`"
)
return values
def revert_calibration(self, values: np.ndarray | list, motor_names: list[str] | None):
"""Inverse of `apply_calibration`."""
if motor_names is None:
motor_names = self.motor_names
for i, name in enumerate(motor_names):
calib_idx = self.calibration["motor_names"].index(name)
calib_mode = self.calibration["calib_mode"][calib_idx]
if CalibrationMode[calib_mode] == CalibrationMode.DEGREE:
homing_offset = self.calibration["homing_offset"][calib_idx]
motor_idx, model = self.motors[name]
# Convert degrees to homed ticks, then convert the homed ticks to raw ticks
values[i] = convert_degrees_to_ticks(values[i], model)
values[i] = adjusted_to_motor_ticks(values[i], homing_offset, model, self, motor_idx)
elif CalibrationMode[calib_mode] == CalibrationMode.LINEAR:
start_pos = self.calibration["start_pos"][calib_idx]
end_pos = self.calibration["end_pos"][calib_idx]
# Convert from nominal lnear range of [0, 100] % to
# actual motor range of values which can be arbitrary.
values[i] = values[i] / 100 * (end_pos - start_pos) + start_pos
values = np.round(values).astype(np.int32)
return values
def read_with_motor_ids(self, motor_models, motor_ids, data_name, num_retry=NUM_READ_RETRY):
if self.mock:
import tests.mock_scservo_sdk as scs
else:
import scservo_sdk as scs
return_list = True
if not isinstance(motor_ids, list):
return_list = False
motor_ids = [motor_ids]
assert_same_address(self.model_ctrl_table, self.motor_models, data_name)
addr, bytes = self.model_ctrl_table[motor_models[0]][data_name]
group = scs.GroupSyncRead(self.port_handler, self.packet_handler, addr, bytes)
for idx in motor_ids:
group.addParam(idx)
for _ in range(num_retry):
comm = group.txRxPacket()
if comm == scs.COMM_SUCCESS:
break
if comm != scs.COMM_SUCCESS:
raise ConnectionError(
f"Read failed due to communication error on port {self.port_handler.port_name} for indices {motor_ids}: "
f"{self.packet_handler.getTxRxResult(comm)}"
)
values = []
for idx in motor_ids:
value = group.getData(idx, addr, bytes)
values.append(value)
if return_list:
return values
else:
return values[0]
def read(self, data_name, motor_names: str | list[str] | None = None):
if self.mock:
import tests.mock_scservo_sdk as scs
else:
import scservo_sdk as scs
if not self.is_connected:
raise RobotDeviceNotConnectedError(
f"FeetechMotorsBus({self.port}) is not connected. You need to run `motors_bus.connect()`."
)
start_time = time.perf_counter()
if motor_names is None:
motor_names = self.motor_names
if isinstance(motor_names, str):
motor_names = [motor_names]
motor_ids = []
models = []
for name in motor_names:
motor_idx, model = self.motors[name]
motor_ids.append(motor_idx)
models.append(model)
assert_same_address(self.model_ctrl_table, models, data_name)
addr, bytes = self.model_ctrl_table[model][data_name]
group_key = get_group_sync_key(data_name, motor_names)
if data_name not in self.group_readers:
# Very Important to flush the buffer!
self.port_handler.ser.reset_output_buffer()
self.port_handler.ser.reset_input_buffer()
# Create new group reader
self.group_readers[group_key] = scs.GroupSyncRead(
self.port_handler, self.packet_handler, addr, bytes
)
for idx in motor_ids:
self.group_readers[group_key].addParam(idx)
for _ in range(NUM_READ_RETRY):
comm = self.group_readers[group_key].txRxPacket()
if comm == scs.COMM_SUCCESS:
break
if comm != scs.COMM_SUCCESS:
raise ConnectionError(
f"Read failed due to communication error on port {self.port} for group_key {group_key}: "
f"{self.packet_handler.getTxRxResult(comm)}"
)
values = []
for idx in motor_ids:
value = self.group_readers[group_key].getData(idx, addr, bytes)
values.append(value)
values = np.array(values)
if data_name in CALIBRATION_REQUIRED and self.calibration is not None:
values = self.apply_calibration(values, motor_names)
# log the number of seconds it took to read the data from the motors
delta_ts_name = get_log_name("delta_timestamp_s", "read", data_name, motor_names)
self.logs[delta_ts_name] = time.perf_counter() - start_time
# log the utc time at which the data was received
ts_utc_name = get_log_name("timestamp_utc", "read", data_name, motor_names)
self.logs[ts_utc_name] = capture_timestamp_utc()
return values
def write_with_motor_ids(self, motor_models, motor_ids, data_name, values, num_retry=NUM_WRITE_RETRY):
if self.mock:
import tests.mock_scservo_sdk as scs
else:
import scservo_sdk as scs
if not isinstance(motor_ids, list):
motor_ids = [motor_ids]
if not isinstance(values, list):
values = [values]
assert_same_address(self.model_ctrl_table, motor_models, data_name)
addr, bytes = self.model_ctrl_table[motor_models[0]][data_name]
group = scs.GroupSyncWrite(self.port_handler, self.packet_handler, addr, bytes)
for idx, value in zip(motor_ids, values, strict=True):
data = convert_to_bytes(value, bytes, self.mock)
group.addParam(idx, data)
for _ in range(num_retry):
comm = group.txPacket()
if comm == scs.COMM_SUCCESS:
break
if comm != scs.COMM_SUCCESS:
raise ConnectionError(
f"Write failed due to communication error on port {self.port_handler.port_name} for indices {motor_ids}: "
f"{self.packet_handler.getTxRxResult(comm)}"
)
def write(self, data_name, values: int | float | np.ndarray, motor_names: str | list[str] | None = None):
if not self.is_connected:
raise RobotDeviceNotConnectedError(
f"FeetechMotorsBus({self.port}) is not connected. You need to run `motors_bus.connect()`."
)
start_time = time.perf_counter()
if self.mock:
import tests.mock_scservo_sdk as scs
else:
import scservo_sdk as scs
if motor_names is None:
motor_names = self.motor_names
if isinstance(motor_names, str):
motor_names = [motor_names]
if isinstance(values, (int, float, np.integer)):
values = [int(values)] * len(motor_names)
values = np.array(values)
motor_ids = []
models = []
for name in motor_names:
motor_idx, model = self.motors[name]
motor_ids.append(motor_idx)
models.append(model)
if data_name in CALIBRATION_REQUIRED and self.calibration is not None:
values = self.revert_calibration(values, motor_names)
values = values.tolist()
assert_same_address(self.model_ctrl_table, models, data_name)
addr, bytes = self.model_ctrl_table[model][data_name]
group_key = get_group_sync_key(data_name, motor_names)
init_group = data_name not in self.group_readers
if init_group:
self.group_writers[group_key] = scs.GroupSyncWrite(
self.port_handler, self.packet_handler, addr, bytes
)
for idx, value in zip(motor_ids, values, strict=True):
data = convert_to_bytes(value, bytes, self.mock)
if init_group:
self.group_writers[group_key].addParam(idx, data)
else:
self.group_writers[group_key].changeParam(idx, data)
comm = self.group_writers[group_key].txPacket()
if comm != scs.COMM_SUCCESS:
raise ConnectionError(
f"Write failed due to communication error on port {self.port} for group_key {group_key}: "
f"{self.packet_handler.getTxRxResult(comm)}"
)
# log the number of seconds it took to write the data to the motors
delta_ts_name = get_log_name("delta_timestamp_s", "write", data_name, motor_names)
self.logs[delta_ts_name] = time.perf_counter() - start_time
# TODO(rcadene): should we log the time before sending the write command?
# log the utc time when the write has been completed
ts_utc_name = get_log_name("timestamp_utc", "write", data_name, motor_names)
self.logs[ts_utc_name] = capture_timestamp_utc()
def disconnect(self):
if not self.is_connected:
raise RobotDeviceNotConnectedError(
f"FeetechMotorsBus({self.port}) is not connected. Try running `motors_bus.connect()` first."
)
if self.port_handler is not None:
self.port_handler.closePort()
self.port_handler = None
self.packet_handler = None
self.group_readers = {}
self.group_writers = {}
self.is_connected = False
def __del__(self):
if getattr(self, "is_connected", False):
self.disconnect()