Safety_module

Node that interacts with the Flexisoft Safety Module via Modbus protocl

1.Dependencies

1.1 ROS dependencies

• robotnik_msgs
• robotnik_modbus_io: The communication with modbus id done through this node

2. Start-up

First, you need robotnik_modbus_io node running (check that the IP is correct)

roslaunch robotnik_modbus_io robotnik_modbus_io.launch

After that, run the node:

roslaunch safety_module safety_module_node.launch

3. Params

Most params are to configure modbus addresses and I/O numbers.

• desired_freq(double)

• address_registers: list of all the addresses to work with registers

  • laser_mode_output(unsigned int): writes the desired laser mode
  • current_speed(unsigned int): writes the current robot speed

• outputs: list of the standard outputs to interact with module

  • standby(unsigned int): sets the lasers and safety module into standby, disabling power in motors and scans
  • watchdog_signals(array of two unsigned int): sets a quadratic signal that allows the Flexisoft module to know that the controller is alive. Otherwise it disables power. Setting an empty array [] means to disable the publication of the signal.
  • emergency_stop_sw(unsigned int): causes E-Stop hardware equivalent

• lasers_mode: available configuration for the lasers safety mode. By default "standard". Example:

  standard:     #  custom name of the mode
    input: 237  # input to read the mode
    output: 0   # value of the register when writing in the modbus address for the lasers mode

• custom_outputs: list of custom outputs mapped and tagged for specific applications

• inputs: list of inputs read from the module

  • emergency_stop
  • auto_mode
  • emergency_mode
  • manual_mode
  • safety_overrided
  • safety_stop
  • standby
  • wheels_power_enabled
  • laser_ok
  • edm_fault
  • emergency_stop_fault
  • motion_enabled
  • emergency_stop_sw
  • watchdog_ok
  • lasers
    • front:
      • detecting_obstacles: True if there's an obstacle in the stop area
      • contamination_led:
      • reset_pressed:
      • free_warning:
    • rear:
      • detecting_obstacles:
      • contamination_led:
      • reset_pressed:
      • free_warning:

• custom_inputs:

watchdog_signals_frequency(double): frequency to write the quadratic signal to keep the module set_speed_feedback_to_safety_module(bool): sets the current speed to the safety module

4. Topics

4.1 Publishers

• ~/safety_module/emergency_stop [std_msgs/Bool]
• ~/safety_module/named_io [robotnik_msgs/named_inputs_outputs] It publishes the current state of all the signals, the standard and custom ones.

digital_inputs: 
  - 
    name: "wheels_power_enabled"
    value: True
  - 
    name: "watchdog_ok"
    value: False
  - 
    name: "edm_fault"
    value: False
  - 
    name: "battery_ok"
    value: True
  - 
    name: "elevator_down"
    value: False
  - 
    name: "elevator_up"
    value: False
  - 
    name: "charge_photocell_fault"
    value: True
  - 
    name: "selector_fault"
    value: False
  - 
    name: "laser_ok"
    value: True
  - 
    name: "emergency_stop_fault"
    value: False
  - 
    name: "emergency_stop_sw"
    value: False
  - 
    name: "motion_enabled"
    value: True
  - 
    name: "ready_to_swap_batteries"
    value: False
digital_outputs: 
  - 
    name: "release_battery"
    value: False
  - 
    name: "block_battery"
    value: False
  - 
    name: "emergency_stop_sw"
    value: False

• ~/safety_module/safety_stop [std_msgs/Bool] It publishes true if the safety is triggered.

• ~/safety_module/speed_feedback [std_msgs/Int32] Current speed being sent to the module.

• ~/safety_module/state [robotnik_msgs/State] Current component state

state: 300
desired_freq: 5.0
real_freq: 4.99675226212
state_description: "READY_STATE"

• ~/safety_module/status [robotnik_msgs/SafetyModuleStatus] This one gives you the status of the module

safety_mode: "safe"
charging: False
emergency_stop: False
safety_stop: True
safety_overrided: False
lasers_on_standby: False
lasers_mode: 
  name: "standard"
lasers_status: 
  - 
    name: "front"
    detecting_obstacles: False
    contaminated: False
    free_warning: False
  - 
    name: "rear"
    detecting_obstacles: False
    contaminated: False
    free_warning: False

• ~/safety_module/watchdog_signals [robotnik_msgs/BoolArray] Current value of the signals sent to the module. For debugging

4.2 Subscribers

• /base/odom [nav_msgs/Odometry]
  • Receives the odometry from the robot
• /base/robotnik_modbus_io/input_output [robotnik_msgs/inputs_outputs]
  • Receives the current IO modbus state

Services

• ~/safety_module/set_laser_mode [robotnik_msgs/SetLaserMode] Sets the current laser mode based on internal configuration. Modes available: standard, docking_station This modes will change the laser detection ranges

• ~/safety_module/set_named_output [robotnik_msgs/SetNamedDigitalOutput] Sets any of the named digital outputs set in configuration.

• ~/safety_module/set_to_standby [std_srvs/SetBool] Puts the module on standby, disabling power and the lasers.