This guide provides detailed instructions for deploying the Alius DCU Controller into an actual robotic system. Please follow the steps in this section to ensure the system operates safely and stably.

Safety Precautions

Before starting the deployment, please read the following safety precautions:

  • Power Safety: Ensure the input voltage is within the 9-36 VDC range. Confirm the power is off before wiring.
  • Electrostatic Discharge (ESD) Protection: Before touching the DCU board, please wear an anti-static wrist strap or touch a grounded metal object to discharge static electricity.
  • Isolation Protection: The CAN and RS-485 interfaces already have electrical isolation, but you still need to ensure good system grounding.
  • Thermal Management: The DCU uses a passive cooling design. When installing, ensure there is sufficient air flow space around the heatsink.

Mechanical Installation

Choosing the Installation Location

When selecting the installation location for the DCU, consider the following factors:

  1. Thermal Space: Reserve at least 20 mm of thermal space above the DCU (heatsink side) to ensure natural air convection.
  2. Vibration Isolation: If installed in a location with significant vibration (such as near robot joints), it is recommended to use rubber damping pads.
  3. Water and Dust Protection: The DCU itself does not have a waterproof function. If used outdoors or in humid environments, a protective enclosure must be added.
  4. Maintenance Accessibility: The installation location should facilitate access to debug interfaces and observation of indicator lights.

Installation Steps

  1. Mark the positions of the 4 M3 mounting holes on the robot chassis or mounting plate.
  2. Drill holes using a 3 mm drill bit and tap M3 threads (or use nuts to secure).
  3. Place insulating spacers (provided with the product) between the DCU and the mounting plate.
  4. Secure the DCU to the mounting plate using 4 M3 screws, controlling the torque at 0.5-0.8 N·m.
  5. Check that the installation is secure and the board is flat.

Electrical Connections

Power Connection

The DCU’s power input uses a 2-pin terminal block (3.81 mm pitch):

  1. Strip about 7 mm of insulation from the power wires.
  2. Insert the positive power wire (usually red) into the VIN terminal and tighten the screw counterclockwise.
  3. Insert the negative power wire (usually black) into the GND terminal and tighten the screw counterclockwise.
  4. Gently pull the power wires to confirm a reliable connection.
  5. Use a multimeter to measure the voltage at the terminals to confirm correct polarity and that the voltage is within the allowable range.

Note: The DCU has reverse polarity protection, but incorrect wiring may still cause system instability. Please double-check carefully.

CAN-FD Bus Connection

The DCU provides 2 CAN-FD interfaces, each using a 3-pin terminal block:

Terminal definition:

  • Pin 1: CANH (high-level signal line)
  • Pin 2: CANL (low-level signal line)
  • Pin 3: GND (signal ground)

Connection steps:

  1. Use twisted pair cables (recommended CAT5e or higher) to connect CANH and CANL.
  2. A 120Ω termination resistor should be connected in parallel at both ends of the bus (the DCU has a configurable onboard termination resistor).
  3. Connect the GND of all nodes together, but it should not be confused with the power ground.
  4. Check the bus topology. A daisy chain topology is recommended; avoid star connections.

RS-485 Bus Connection

The DCU provides 2 RS-485 interfaces, each using a 3-pin terminal block:

Terminal definition:

  • Pin 1: A (positive signal line, corresponding to Data+ / D+)
  • Pin 2: B (negative signal line, corresponding to Data- / D-)
  • Pin 3: GND (signal ground)

Connection notes:

  • Twisted pair cables are also recommended for RS-485 buses.
  • A 120Ω termination resistor should be connected in parallel at both ends of the bus.
  • Connecting the ground wire (GND) can reduce common-mode interference and improve communication reliability.

EtherCAT Network Connection

The DCU’s 2 EtherCAT interfaces support daisy chain connection:

  1. Use standard CAT5e or higher Ethernet cables.
  2. Connect Port 0 of the DCU to the first EtherCAT slave.
  3. Connect the output from the first slave to the next slave, and so on.
  4. Correctly set the number of slaves and topology structure in the system configuration.

System Configuration

First Boot Configuration

  1. Turn on the power and log in to the system via the debug serial port.
  2. Change the default password:
passwd
  1. Configure the hostname:
sudo hostnamectl set-hostname dcu-robot-001
  1. Configure the network (static IP is recommended for robotic systems):
sudo nano /etc/network/interfaces

# Add the following content
auto eth0
iface eth0 inet static
    address 192.168.1.100
    netmask 255.255.255.0
    gateway 192.168.1.1
  1. Configure timezone and time synchronization:
sudo timedatectl set-timezone Asia/Shanghai
sudo apt install -y chrony
sudo systemctl enable chrony

RTOS Coprocessor Configuration

The DCU’s RTOS coprocessor is responsible for real-time control tasks and requires the following configuration:

  1. Edit the RTOS configuration file:
sudo nano /opt/aliu/rtos/config.json
  1. Configure parameters such as control cycle and task priority according to application requirements.
  2. Restart the RTOS service to apply the configuration:
sudo systemctl restart aliu-rtos

Application Deployment

Deploy Alius Robot Control Software Stack

Alius provides a complete robot control software stack that can be deployed in the following way:

# Add Alius software repository
curl -fsSL https://packages.aliu.tech/gpg | sudo apt-key add -
echo "deb https://packages.aliu.tech dcu main" | sudo tee /etc/apt/sources.list.d/aliu.list

# Install core packages
sudo apt update
sudo apt install -y aliu-core aliu-can aliu-ethercat

Configure Auto-start

In production environments, it is usually necessary to configure the control software as a system service for automatic startup:

# Create systemd service file
sudo nano /etc/systemd/system/robot-control.service

# File content:
# [Unit]
# Description=Alius Robot Control Service
# After=network.target aliu-rtos.service
#
# [Service]
# Type=simple
# User=aliu
# WorkingDirectory=/opt/robot
# ExecStart=/opt/robot/control_node
# Restart=always
# RestartSec=5
#
# [Install]
# WantedBy=multi-user.target

# Enable service
sudo systemctl enable robot-control.service
sudo systemctl start robot-control.service

Deployment Checklist

After completing the deployment, please use the following checklist to verify the system status:

  • Input voltage is within the allowable range
  • All interface connections are secure, screws are tightened
  • System boots normally without abnormal logs
  • Network connection is normal, latency < 1 ms (LAN)
  • CAN-FD bus communication is normal without error frames
  • RS-485 communication is normal
  • All EtherCAT slaves are online
  • RTOS coprocessor is running normally
  • NPU inference function is normal
  • Control software starts automatically on boot
  • System time is synchronized
  • Heatsink temperature < 70°C (full load)