Throws wrong type error while parsing ompl_planning.yaml

[jrgnicho]

Description

In loading the config yaml files for MoveItCPP in my application,
an incorrect yaml type error is thrown when parsing the ompl_planning.yaml file

Overview of your issue here.
I don't have a screen capture of the actual error message but it seemed to suggest that it expected a string but got a double instead. I was able to get it to accept the yaml file by placing quotes around the value assigned to longest_valid_segment_fraction field in order to make it a string, see here

Your environment

• ROS Distro: [Eloquent]
• OS Version: e.g. Ubuntu 18.04
• Source
• master branch

Steps to reproduce

Load ompl_planning.yaml file which includes the longest_valid_segment_fraction set to a double

Expected behaviour

MoveItCPP should load the yaml file and configure itself from it

Actual behaviour

Throws exception saying that it expected a string but got a double instead

Backtrace or Console output

Did't capture :(

[JafarAbdi]

You're right, it's a bug in ompl_interface.cpp#L181 it loop over the parameters' name and expect string for all of them which isn't the case here

In ROS1 calling a getParam with a different type return false, in ROS2 it throws an exception

[jrgnicho]

I see, that'll be tricky to get to work right if it throws an exception

[JafarAbdi]

@jrgnicho How about adding a map of KNOWN_GROUP_PARAMS and ParameterType and getting the parameter that matches the parameter type .?

[ddengster]

rclcpp::Parameter param = node_->get_parameter(group_name_param + "." + k);
        if (param.get_type() == rclcpp::ParameterType::PARAMETER_STRING)
        {
          std::string value = param.get_value<std::string>();
          if (!value.empty())
            specific_group_params[k] = value;
          continue;
        }
        else if (param.get_type() == rclcpp::ParameterType::PARAMETER_DOUBLE)
        {
          double value_d = param.get_value<double>();
          // convert to string using no locale
          specific_group_params[k] = moveit::core::toString(value_d);
          continue;
        }
        else if (param.get_type() == rclcpp::ParameterType::PARAMETER_INTEGER)
        {
          int value_i = param.get_value<int>();
          specific_group_params[k] = std::to_string(value_i);
          continue;
        }
        else if (param.get_type() == rclcpp::ParameterType::PARAMETER_BOOL)
        {
          bool value_b = param.get_value<bool>();
          specific_group_params[k] = std::to_string(value_b);
          continue;
        }

Something like this should work.

sidetrack: I have a working move_group node, i'm a bug away from a working version (and a draft PR). If you happen to be fixing a bug that occurs with the srdf injesting the joint values of a group_state with the wrong joint order let me know if you've found a solution. turns out the solution was to port joint reordering functionality over in joint_trajectory_controller. I've integrated it into the pr.

[henningkayser]

Something like this should work.

Probably, but in general I would prefer either a template function (instead of explicit type checks) or introducing a convention that forbids variable types. I also thought that there are already some implicit conversions available, at least for double and int.

sidetrack: I have a working move_group node, i'm a bug away from a working version (and a draft PR). If you happen to be fixing a bug that occurs with the srdf injesting the joint values of a group_state with the wrong joint order let me know if you've found a solution.

That's interesting, could you start an issue on that?

[jrgnicho]

rclcpp::Parameter param = node_->get_parameter(group_name_param + "." + k);
        if (param.get_type() == rclcpp::ParameterType::PARAMETER_STRING)
        {
          std::string value = param.get_value<std::string>();
          if (!value.empty())
            specific_group_params[k] = value;
          continue;
        }
        else if (param.get_type() == rclcpp::ParameterType::PARAMETER_DOUBLE)
        {
          double value_d = param.get_value<double>();
          // convert to string using no locale
          specific_group_params[k] = moveit::core::toString(value_d);
          continue;
        }
        else if (param.get_type() == rclcpp::ParameterType::PARAMETER_INTEGER)
        {
          int value_i = param.get_value<int>();
          specific_group_params[k] = std::to_string(value_i);
          continue;
        }
        else if (param.get_type() == rclcpp::ParameterType::PARAMETER_BOOL)
        {
          bool value_b = param.get_value<bool>();
          specific_group_params[k] = std::to_string(value_b);
          continue;
        }

Something like this should work.

sidetrack: I have a working move_group node, i'm a bug away from a working version (and a draft PR). If you happen to be fixing a bug that occurs with the srdf injesting the joint values of a group_state with the wrong joint order let me know if you've found a solution.

That should work but I'm with @henningkayser on preferring template functions

[ddengster]

That's interesting, could you start an issue on that?

turns out the solution was to port joint reordering functionality over in joint_trajectory_controller. I've integrated it into the jtc pr.

[henningkayser]

That's interesting, could you start an issue on that?

turns out the solution was to port joint reordering functionality over in joint_trajectory_controller. I've integrated it into the jtc pr.

Great, thanks!