Files
lerobot/lerobot/common/motors/feetech/feetech.py
2025-03-15 19:22:12 +01:00

486 lines
17 KiB
Python

# Copyright 2024 The HuggingFace Inc. team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from copy import deepcopy
import numpy as np
from ..motors_bus import (
CalibrationMode,
JointOutOfRangeError,
MotorsBus,
assert_same_address,
get_group_sync_key,
)
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, model: str, motorbus, motor_id: int) -> int:
"""
Takes a raw reading [0..(res-1)] (e.g. 0..4095) and shifts it so that '2048'
becomes 0 in the homed coordinate system ([-2048..+2047] for 4096 resolution).
"""
resolutions = MODEL_RESOLUTION[model]
# Shift raw ticks by half-resolution so 2048 -> 0, then wrap [0..res-1].
ticks = (raw_motor_ticks - (resolutions // 2)) % resolutions
# If above halfway, fold it into negative territory => [-2048..+2047].
if ticks > (resolutions // 2):
ticks -= resolutions
# Flip sign if drive_mode is set.
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, model: str, motorbus, motor_id: int) -> int:
"""
Inverse of adjusted_to_homing_ticks(). Takes a 'homed' position in [-2048..+2047]
and recovers the raw [0..(res-1)] ticks with 2048 as midpoint.
"""
# Flip sign if drive_mode was set.
drive_mode = 0
if motorbus.calibration is not None:
drive_mode = motorbus.calibration["drive_mode"][motor_id - 1]
if drive_mode:
adjusted_pos *= -1
resolutions = MODEL_RESOLUTION[model]
# Shift by +half-resolution and wrap into [0..res-1].
# This undoes the earlier shift by -half-resolution.
ticks = (adjusted_pos + (resolutions // 2)) % resolutions
return ticks
def convert_to_bytes(value, n_bytes: int):
import scservo_sdk as scs
# Note: No need to convert back into unsigned int, since this byte preprocessing
# already handles it for us.
if n_bytes == 1:
data = [
scs.SCS_LOBYTE(scs.SCS_LOWORD(value)),
]
elif n_bytes == 2:
data = [
scs.SCS_LOBYTE(scs.SCS_LOWORD(value)),
scs.SCS_HIBYTE(scs.SCS_LOWORD(value)),
]
elif n_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"{n_bytes} is provided instead."
)
return data
class FeetechMotorsBus(MotorsBus):
"""
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"
motors_bus = FeetechMotorsBus(
port="/dev/tty.usbmodem575E0031751",
motors={motor_name: (motor_index, motor_model)},
)
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()
```
"""
model_ctrl_table = deepcopy(MODEL_CONTROL_TABLE)
model_resolution_table = deepcopy(MODEL_RESOLUTION)
model_baudrate_table = deepcopy(MODEL_BAUDRATE_TABLE)
def __init__(
self,
port: str,
motors: dict[str, tuple[int, str]],
):
super().__init__(port, motors)
def _set_handlers(self):
import scservo_sdk as scs
self.port_handler = scs.PortHandler(self.port)
self.packet_handler = scs.PacketHandler(PROTOCOL_VERSION)
def _set_timeout(self, timeout: int = TIMEOUT_MS):
self.port_handler.setPacketTimeoutMillis(timeout)
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:
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], 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:
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], 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):
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):
import scservo_sdk as scs
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)
return values
def write_with_motor_ids(self, motor_models, motor_ids, data_name, values, num_retry=NUM_WRITE_RETRY):
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)
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: str, values: list[int], motor_names: list[str]) -> None:
import scservo_sdk as scs
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)
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)
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)}"
)