This is an open-source demo related to the eRob product, provided solely for reference by developers. Please note that issues within the open-source project are independent of the quality of eRob products. Users are advised to exercise caution while using the demo. We are not responsible for any damage caused by improper operations. For any project errors, please raise a query in the Issues section. Collaboration and forks to resolve open-source project issues are welcome.

eRob ROS2 MoveIt

The new versions of erob_position_control and erobo3_control have added timeout settings and provide a solution to address the issue where eRob cannot enter DC mode in the ethercat_ros2 interface. result

Resolving eRob DC Mode and OP Mode Issues

1. Problem Analysis

The issues related to eRob failing to enter DC mode and OP mode are likely caused by:

1. eRob Failing to Enter DC Mode
   • The issue is potentially related to the version of igh_ethercat and modifications in ros2_ethercat_driver.
2. eRob Entering DC Mode but Failing to Enter OP Mode
   • This is likely due to incorrect ROS2 control cycle settings, which affect synchronization.

2. Solution Steps

(1) Resolving the Issue of eRob Failing to Enter DC Mode

Upgrade EtherCAT Version

• Update igh_ethercat from version 1.5.2 to 1.6.3 to improve compatibility and DC mode handling.

Modify ros2_ethercat_driver

• In ros2_ethercat_driver/ethercat_interface/src/ec_master.cpp, remove the DC configuration check (approximately around line 100).
• Ensure the DC configuration is executed by keeping the following code:

struct timespec t;
clock_gettime(CLOCK_MONOTONIC, &t);
ecrt_master_application_time(master_, EC_NEWTIMEVAL2NANO(t));
ecrt_slave_config_dc(
  slave_info.config,
  slave->assign_activate_dc_sync(),
  interval_,
  interval_ - (t.tv_nsec % (interval_)),
  0,
  0);

Recompile and Verify

• Recompile ros2_ethercat_driver and the eRob application project.
• After making these changes, verify that:
  • Register 0x1C32 is set to 2.
  • Register 0x0981 is set to 3.

(2) Resolving the Issue of eRob Entering DC Mode but Failing to Enter OP Mode

Adjust the ROS2 Control Cycle

• Set the ROS2 control cycle to half of the EtherCAT slave control cycle to ensure proper synchronization.
• Incorrect cycle settings may prevent the system from entering OP mode successfully.

(3) Additional Improvements

Add Parameter Configuration for Timeout

• To improve reliability, add a timeout parameter to handle unexpected delays or failures.
• Ensure the configuration settings allow for proper system recovery in case of synchronization issues.

3. Final Results

• Steps 1, 2, and 3 resolve the issue of eRob failing to enter DC mode.
• Step 4 ensures eRob can enter OP mode and function correctly.

Installation Required Dependencies

1. Installing the Preempt-RT Real-Time Patch on Ubuntu 22.04

1.1 Check Kernel Version and Install Necessary Packages

uname -a

1.2 Install Necessary Packages

apt install autoconf automake libtool make libncurses-dev flex bison libelf-dev libssl-dev zstd net-tools

1.3 Download the Kernel and Patches

https://mirrors.edge.kernel.org/pub/linux/kernel/

Download the Linux kernel from the Link. Find your version—it’s not the small files above, scroll down to find the Linux kernel files starting with “Linux” that are over 100MB.

https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/

Download the real-time patches from the Link. Make sure to choose the patch that matches your kernel version.

1.4 Extract and Apply the Patch

tar -zxvf linux-5.19.tar.gz
xz -d patch-5.19-rt10.patch.xz

cd linux-5.19/
patch -p1 < ../patch-5.19-rt10.patch

1.5 Kernel Configuration

make menuconfig

After entering the graphical configuration interface, perform the following operations:

• General Setup -> Preemption Model -> Fully Preemptible Kernel(RT)
• General Setup -> Timers subsystem -> Timer tick handling -> Full dynticks system
• General Setup -> Timers subsystem -> High Resolution Timer Support
• Processor type and features -> Timer frequency -> 1000 HZ

Remember to save and exit.

vi .config

CONFIG_SYSTEM_TRUSTED_KEYS=""

CONFIG_SYSTEM_REVOCATION_KEYS=""

Save and exit.

1.6 Compile and Install

make -j8`nproc`

After completion:

make modules_install
make install

1.7 Configure GRUB Boot Options

vim /etc/default/grub

• Comment out the following line to display the boot menu:

GRUB_TIMEOUT_STYLE=hidden

• Adjust the timeout value:

GRUB_TIMEOUT=5  # Timeout in seconds

• Update GRUB configuration:

update-grub

1.8 Reboot

1.9 Testing

apt-get install rt-tests 
cyclictest -t 5 -p 80 -i 1000

cyclictest will perform 1000 cyclic tests over 5 seconds at the highest priority to measure the real-time performance of the Linux system. After the test, cyclictest will output statistical information about the test results.

2. ROS2-Humble

It is easy to be installed by learning ROS2 documentation: Humble

3. ROS2-Control

It is easy to be installed by learning this link

4. MoveIt2

It is easy to be installed by learning this link

5. IGH-EtherCAT

### 5.1 Installing EtherLab
It is easy to be installed by learning this link

### 5.2 Building ethercat_driver_ros2

It is easy to be installed by learning this link

6. ROS2_eRob_MoveIt

mkdir eRob_moveit/src
cd  eRob_moveit/src
git clone https://github.com/ZeroErrControl/eRob_ROS2_MoveIt
cd ..
colcon build 

source ./install/setup.bash

ros2 launch erob_position_control demo.launch.py
ros2 launch erobo3_control demo.launch.py