SpeedStream.java

/**
 * Copyright 2012 Kevin J. Jones (http://www.kevinjjones.co.uk)
 *
 * 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.
 */
package uk.co.kevinjjones.vehicle;

import uk.co.kevinjjones.Log;
import uk.co.kevinjjones.model.*;

/**
 * Speed virtual stream.
 */
public class SpeedStream extends StreamBase {

    public static String NAME = "Speed";
    private View _view;
    private ROStream _lusp;
    private ROStream _rusp;
    private ROStream _ldsp;
    private ROStream _rdsp;
    private ROStream _lowt;

    public SpeedStream() {
    }

    @Override
    public void setView(View view, Object arg, ParamHandler handler, WithError<Boolean, BasicError> ok) {
        super.setView(view, arg, handler, ok);
        _view = view;
        _lusp = _view.getStream(WheelStream.name(WheelStream.LUSP));
        _rusp = _view.getStream(WheelStream.name(WheelStream.RUSP));
        _ldsp = _view.getStream(WheelStream.name(WheelStream.LDSP));
        _rdsp = _view.getStream(WheelStream.name(WheelStream.RDSP));
        _lowt = _view.getStream(LowThrottleStream.NAME);

        if (_lusp != null && _rusp != null && _ldsp != null && _rdsp != null) {
            ok.addError(new BasicError(BasicError.WARN, "Using four wheel speeds to calculate speed"));
        } else if (_lusp != null && _rusp != null) {
            ok.addError(new BasicError(BasicError.WARN, "Using two undriven wheel sensors to calculate speed"));
        } else if (_lusp != null) {
            ok.addError(new BasicError(BasicError.WARN, "Using left undriven wheel sensors to calculate speed"));
        } else if (_rusp != null) {
            ok.addError(new BasicError(BasicError.WARN, "Using right undriven wheel sensors to calculate speed"));
        } else if (_ldsp != null && _rdsp != null) {
            ok.addError(new BasicError(BasicError.WARN, "Using two driven wheel sensors to calculate speed"));
        } else if (_ldsp != null) {
            ok.addError(new BasicError(BasicError.WARN, "Using left driven wheel sensors to calculate speed"));
        } else if (_rdsp != null) {
            ok.addError(new BasicError(BasicError.WARN, "Using right driven wheel sensors to calculate speed"));
        } else {
            ok.addError(new BasicError(BasicError.WARN, "No wheel speeds available"));
            ok.setValue(false);
        }
    }

    @Override
    public String name() {
        return NAME;
    }

    @Override
    public String description() {
        return "Speed";
    }

    @Override
    public String axis() {
        return "Speed";
    }

    @Override
    public String units() {
        switch (isKPH(false)) {
            case 1:
                return "kph";
            case 2:
                return "mph";
        }
        return null;
    }

    @Override
    public int size() {
        return _view.getStream(Log.TIME_STREAM).size();
    }
    
    private double safeAverage(double v1, double v2) {
        if (v1 != 0 && v2 != 0) {
            return (v1+v2)/2;
        } else if (v1 != 0) {
            return v1;
        } else {
            return v2;
        }
    }

    @Override
    public double getNumeric(int position) throws NumberFormatException {

        if (_lusp != null && _rusp != null && _ldsp != null && _rdsp != null) {
            // With four wheel sensors we track undriven under accel
            // and driven under braking by looking at tps 
            // at tps
            double avgDriven = safeAverage(_ldsp.getNumeric(position), _rdsp.getNumeric(position));
            double avgUndriven = safeAverage(_lusp.getNumeric(position), _rusp.getNumeric(position));

            if (_lowt != null && _lowt.getNumeric(position) == 1) {
                return avgDriven;
            } else {
                return avgUndriven;
            }
        } else if (_lusp != null && _rusp != null) {
            // With only 2 undriven go for max to remove lock ups
            return Math.max(_lusp.getNumeric(position), _rusp.getNumeric(position));
        } else if (_lusp != null) {
            return _lusp.getNumeric(position);
        } else if (_rusp != null) {
            return _rusp.getNumeric(position);
        } else if (_ldsp != null && _rdsp != null) {
            // With only 2 undriven go for min to remove spin
            return Math.min(_ldsp.getNumeric(position), _rdsp.getNumeric(position));
        } else if (_ldsp != null) {
            return _ldsp.getNumeric(position);
        } else if (_rdsp != null) {
            return _rdsp.getNumeric(position);
        }
        return 0;
    }
}