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Moving NAO’s head

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The aim of this example is to show how to move NAO using a proxy to ALMotion. This particular example will make NAO’s head move right and left.

The whole example is available here:

Source file:


* Copyright (c) 2011 Aldebaran Robotics. All Rights Reserved
* \file movehead.cpp
* \brief Move NAO's head.
* A simple example showing how to move NAO's head by using ALMotionProxy.
* This example will make NAO turn its head left and right slowly.
* We use here a specialized proxy to ALMotion.

#include <iostream>
#include <alerror/alerror.h>
#include <alproxies/almotionproxy.h>

int main(int argc, char* argv[]) {

  if(argc != 2)
    std::cerr << "Wrong number of arguments!" << std::endl;
    std::cerr << "Usage: movehead NAO_IP" << std::endl;

  /** The name of the joint to be moved. */
  const AL::ALValue jointName = "HeadYaw";

  try {
    /** Create a ALMotionProxy to call the methods to move NAO's head.
    * Arguments for the constructor are:
    * - IP adress of the robot
    * - port on which NAOqi is listening, by default 9559
    AL::ALMotionProxy motion(argv[1], 9559);

    /** Make sure the head is stiff to be able to move it.
    * To do so, make the stiffness go to the maximum in one second.
    /** Target stiffness. */
    AL::ALValue stiffness = 1.0f;
    /** Time (in seconds) to reach the target. */
    AL::ALValue time = 1.0f;
    /** Call the stiffness interpolation method. */
    motion.stiffnessInterpolation(jointName, stiffness, time);

    /** Set the target angle list, in radians. */
    AL::ALValue targetAngles = AL::ALValue::array(-1.5f, 1.5f, 0.0f);
    /** Set the corresponding time lists, in seconds. */
    AL::ALValue targetTimes = AL::ALValue::array(3.0f, 6.0f, 9.0f);
    /** Specify that the desired angles are absolute. */
    bool isAbsolute = true;

    /** Call the angle interpolation method. The joint will reach the
    * desired angles at the desired times.
    motion.angleInterpolation(jointName, targetAngles, targetTimes, isAbsolute);

    /** Remove the stiffness on the head. */
    stiffness = 0.0f;
    time = 1.0f;
    motion.stiffnessInterpolation(jointName, stiffness, time);

  catch (const AL::ALError& e) {
    std::cerr << "Caught exception: " << e.what() << std::endl;


The corresponding CMakeLists.txt file is the following


# Copyright (c) 2011 Aldebaran Robotics. All Rights Reserved.

cmake_minimum_required(VERSION 2.6.4 FATAL_ERROR)
# Give a name to the project.
# This include enable you to use our CMake framework

# Create an executable named movehead,
# with the source file : movehead.cpp
qi_create_bin(movehead movehead.cpp)

# Tell CMake that movehead depends on ALCOMMON and ALPROXIES
# This will set the libraries to link movehead with,
# the include paths, and so on
qi_use_lib(movehead ALCOMMON ALPROXIES)