param_parser.cpp

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/*
 * Copyright 2017 Fraunhofer Institute for Manufacturing Engineering and Automation (IPA)
 *
 * 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.
 */
 
 
#include <cob_omni_drive_controller/param_parser.h>
#include <cob_omni_drive_controller/UndercarriageCtrlGeomROS.h>
#include <urdf/model.h>
#include <angles/angles.h>
#include <XmlRpcException.h>
 
#include <tf2/LinearMath/Quaternion.h>
#include <tf2/LinearMath/Transform.h>
#include <tf2/LinearMath/Vector3.h>
 
class MergedXmlRpcStruct : public XmlRpc::XmlRpcValue{
    MergedXmlRpcStruct(const XmlRpc::XmlRpcValue& a) :XmlRpc::XmlRpcValue(a){ assertStruct(); }
public:
    MergedXmlRpcStruct(){ assertStruct(); }
    MergedXmlRpcStruct(const XmlRpc::XmlRpcValue& a, const MergedXmlRpcStruct &b, bool recursive= true) :XmlRpc::XmlRpcValue(a){
        assertStruct();
 
        for(ValueStruct::const_iterator it = b._value.asStruct->begin(); it != b._value.asStruct->end(); ++it){
            std::pair<XmlRpc::XmlRpcValue::iterator,bool> res =  _value.asStruct->insert(*it);
 
            if(recursive && !res.second && res.first->second.getType() == XmlRpc::XmlRpcValue::TypeStruct && it->second.getType() == XmlRpc::XmlRpcValue::TypeStruct){
                res.first->second = MergedXmlRpcStruct(res.first->second, it->second); // recursive struct merge with implicit cast
            }
        }
 
 
    }
};
 
template<typename T> T read_typed(XmlRpc::XmlRpcValue &val){
    return val;
}
template<> double read_typed(XmlRpc::XmlRpcValue &val){
    if(val.getType() ==  XmlRpc::XmlRpcValue::TypeInt) return read_typed<int>(val);
    return val;
}
 
template<typename T> bool read_optional(T& val, const std::string &name, XmlRpc::XmlRpcValue &wheel){
    try{
        if(wheel.hasMember(name)){
           val = read_typed<T>(wheel[name]);
           return true;
        }
    }catch(XmlRpc::XmlRpcException &e){
        ROS_ERROR_STREAM("Could not access '" << name << "', reason: " << e.getMessage());
    }
    return false;
}
 
template<typename T> bool read_with_default(T& val, const std::string &name, XmlRpc::XmlRpcValue &wheel, const T& def){
    if(!read_optional(val, name, wheel)){
        val = def;
        return false;
    }
    return true;
}
 
template<typename T> bool read(T& val, const std::string &name, XmlRpc::XmlRpcValue &wheel){
    if(!read_optional(val, name, wheel)){
        ROS_ERROR_STREAM("Parameter not found: " << name);
        return false;
    }
    return true;
}
 
bool parseCtrlParams(CtrlParams & params, XmlRpc::XmlRpcValue &wheel, urdf::Model* model){
    double deg;
    read_with_default(deg, "steer_neutral_position", wheel, 0.0);
    params.dWheelNeutralPos = angles::from_degrees(deg);
 
    std::string steer_name, drive_name;
    double max_steer_rate, max_drive_rate;
    read_with_default(steer_name, "steer", wheel, std::string());
    read_with_default(drive_name, "drive", wheel, std::string());
 
    urdf::JointConstSharedPtr steer_joint;
    if(model && !steer_name.empty()){
        steer_joint = model->getJoint(steer_name);
        if(steer_joint){
            params.dMaxSteerRateRadpS = steer_joint->limits->velocity;
        }
    }
    if(!read_optional(params.dMaxSteerRateRadpS, "max_steer_rate", wheel) && !steer_joint){
        ROS_WARN_STREAM("max_steer_rate not set - defaulting to 0.0");
        params.dMaxSteerRateRadpS = 0.0;
    }
    urdf::JointConstSharedPtr drive_joint;
    if(model && !drive_name.empty()){
        drive_joint = model->getJoint(drive_name);
        if(drive_joint){
            params.dMaxDriveRateRadpS = drive_joint->limits->velocity;
        }
    }
    if(!read_optional(params.dMaxDriveRateRadpS, "max_drive_rate", wheel) && !drive_joint){
        ROS_WARN_STREAM("max_drive_rate not set - defaulting to 0.0");
        params.dMaxDriveRateRadpS = 0.0;
    }
 
    ROS_DEBUG_STREAM("max_steer_rate: " <<  params.dMaxSteerRateRadpS);
    ROS_DEBUG_STREAM("max_drive_rate: " <<  params.dMaxDriveRateRadpS);
    
    return true;
}
 
bool parsePosCtrlParams(PosCtrlParams & params, XmlRpc::XmlRpcValue &wheel){
    if(!wheel.hasMember("steer_ctrl")){
        ROS_ERROR_STREAM("steer_ctrl not found");
        return false;
    }
    XmlRpc::XmlRpcValue &steer = wheel["steer_ctrl"];
 
    return read(params.dSpring, "spring", steer)
        && read(params.dDamp, "damp", steer)
        && read(params.dVirtM, "virt_mass", steer)
        && read(params.dDPhiMax, "d_phi_max", steer)
        && read(params.dDDPhiMax, "dd_phi_max", steer);
}
 
bool parseWheelGeom(WheelGeom & geom, XmlRpc::XmlRpcValue &wheel, MergedXmlRpcStruct &merged, urdf::Model* model){
 
    read_with_default(geom.steer_name, "steer", wheel, std::string());
    read_with_default(geom.drive_name, "drive", wheel, std::string());
    read_with_default(geom.dSteerDriveCoupling, "steer_drive_coupling", wheel, 0.0);
 
    urdf::JointConstSharedPtr steer_joint;
    urdf::Vector3 steer_pos;
 
    if(model && !geom.steer_name.empty()){
        steer_joint = model->getJoint(geom.steer_name);
        if(steer_joint){
            tf2::Transform transform;
            if(parseWheelTransform(geom.steer_name, model->getRoot()->name, transform, model)){
                steer_pos.x = transform.getOrigin().getX();
                steer_pos.y = transform.getOrigin().getY();
                steer_pos.z = transform.getOrigin().getZ();
            }
        }
    }
 
    if(!read_optional(steer_pos.x, "x_pos", wheel) && !steer_joint){
        ROS_ERROR_STREAM("Could not parse x_pos");
        return false;
    }
 
    if(!read_optional(steer_pos.y, "y_pos", wheel) && !steer_joint){
        ROS_ERROR_STREAM("Could not parse y_pos");
        return false;
    }
 
    if(!read_optional(steer_pos.z, "wheel_radius", merged) && !steer_joint){
        ROS_ERROR_STREAM("Could not parse wheel_radius");
        return false;
    }
 
    if(steer_pos.z == 0){
        ROS_ERROR_STREAM("wheel_radius must be non-zero");
        return false;
    }
 
    ROS_DEBUG_STREAM(geom.steer_name<<" steer_pos \tx:"<<steer_pos.x<<" \ty:"<<steer_pos.y<<" \tz:"<<steer_pos.z);
 
    geom.dWheelXPosMM = steer_pos.x * 1000;
    geom.dWheelYPosMM = steer_pos.y * 1000;
    geom.dRadiusWheelMM = fabs(steer_pos.z * 1000);
 
    double offset = 0;
 
    if(!read_optional(offset, "wheel_offset", merged)){
        urdf::JointConstSharedPtr drive_joint;
        if(model && !geom.drive_name.empty()){
            drive_joint = model->getJoint(geom.drive_name);
        }
        if(drive_joint){
            const urdf::Vector3& pos = drive_joint->parent_to_joint_origin_transform.position;
            offset = sqrt(pos.x*pos.x + pos.y * pos.y);
        }else{
            ROS_ERROR_STREAM("Could not parse wheel_offset");
            return false;
        }
    }
    geom.dDistSteerAxisToDriveWheelMM = offset * 1000;
    return true;
}
 
template<typename W> bool parseWheel(W & params, XmlRpc::XmlRpcValue &wheel, MergedXmlRpcStruct &merged, urdf::Model* model);
 
template<> bool parseWheel(UndercarriageGeom::WheelParams & params, XmlRpc::XmlRpcValue &wheel, MergedXmlRpcStruct &merged, urdf::Model* model){
    return parseWheelGeom(params.geom, wheel, merged, model);
}
 
template<> bool parseWheel(UndercarriageDirectCtrl::WheelParams & params, XmlRpc::XmlRpcValue &wheel, MergedXmlRpcStruct &merged, urdf::Model* model){
    return parseWheelGeom(params.geom, wheel, merged, model) && parseCtrlParams(params.ctrl, merged, model);
}
 
template<> bool parseWheel(UndercarriageCtrl::WheelParams & params, XmlRpc::XmlRpcValue &wheel, MergedXmlRpcStruct &merged, urdf::Model* model){
    return parseWheelGeom(params.geom, wheel, merged, model) && parseCtrlParams(params.ctrl, merged, model) && parsePosCtrlParams(params.pos_ctrl, merged);
}
 
bool make_wheel_struct(XmlRpc::XmlRpcValue &wheel_list){
    if(wheel_list.getType() ==  XmlRpc::XmlRpcValue::TypeArray){
        XmlRpc::XmlRpcValue new_stuct;
        for(size_t i = 0; i < wheel_list.size(); ++i){
            new_stuct[boost::lexical_cast<std::string>(i)] = wheel_list[i];
        }
        wheel_list = new_stuct;
    }else if(wheel_list.getType() !=  XmlRpc::XmlRpcValue::TypeStruct){
        return false;
    }
 
    return wheel_list.size() > 0;
}
 
template<typename W> bool parseWheels(std::vector<W> &wheel_params, const ros::NodeHandle &nh, bool read_urdf){
 
    urdf::Model model;
 
    std::string description_name;
    bool has_model = read_urdf && nh.searchParam("robot_description", description_name) &&  model.initParam(description_name);
 
    MergedXmlRpcStruct defaults;
    nh.getParam("defaults", defaults);
 
    // clear vector in case of reinititialization
    wheel_params.clear();
 
    XmlRpc::XmlRpcValue wheel_list;
    if (!nh.getParam("wheels", wheel_list)){
        ROS_ERROR("List of wheels not found");
        return false;
    }
 
    if (!make_wheel_struct(wheel_list)){
        ROS_ERROR("List of wheels is invalid");
        return false;
    }
 
    for(XmlRpc::XmlRpcValue::iterator it = wheel_list.begin(); it != wheel_list.end(); ++it){
 
        W params;
        MergedXmlRpcStruct merged(it->second, defaults);
 
        if(!parseWheel(params, it->second, merged, has_model?&model:0)){
            return false;
        }
 
        wheel_params.push_back(params);
    }
    return !wheel_params.empty();
}
 
namespace cob_omni_drive_controller{
 
bool parseWheelParams(std::vector<UndercarriageGeom::WheelParams> &params, const ros::NodeHandle &nh, bool read_urdf /* = true*/){
    return parseWheels(params, nh, read_urdf);
}
bool parseWheelParams(std::vector<UndercarriageDirectCtrl::WheelParams> &params, const ros::NodeHandle &nh, bool read_urdf /* = true*/){
    return parseWheels(params, nh, read_urdf);
}
bool parseWheelParams(std::vector<UndercarriageCtrl::WheelParams> &params, const ros::NodeHandle &nh, bool read_urdf /* = true*/){
    return parseWheels(params, nh, read_urdf);
}
 
 
}