Translates from JderobotTypes CMDVel to ROS Twist. 

    @param vel: JderobotTypes CMDVel to translate

    @type img: JdeRobotTypes.CMDVel

    @return a Twist translated from vel

def cmdvel2Twist(vel):
    '''
    Translates from JderobotTypes CMDVel to ROS Twist. 

    @param vel: JderobotTypes CMDVel to translate

    @type img: JdeRobotTypes.CMDVel

    @return a Twist translated from vel

    '''
    tw = TwistStamped()
    tw.twist.linear.x = vel.vx
    tw.twist.linear.y = vel.vy
    tw.twist.linear.z = vel.vz
    tw.twist.angular.x = vel.ax
    tw.twist.angular.y = vel.ay
    tw.twist.angular.z = vel.az

    return tw