PilotNode Class Reference

controls the ART vehicle brake, throttle, steering and transmission More...

Public Member Functions
	PilotNode (ros::NodeHandle node)
void	spin (void)
Private Types
typedef dynamic_reconfigure::Server < Config >	ReconfigServer
Private Member Functions
void	adjustSteering (void)
void	halt (void)
void	monitorHardware (void)
void	processCarCommand (const art_msgs::CarCommand::ConstPtr &msg)
void	processCarDrive (const art_msgs::CarDriveStamped::ConstPtr &msg)
void	processLearning (const art_msgs::LearningCommand::ConstPtr &learningIn)
void	reconfig (Config &newconfig, uint32_t level)
void	speedControl (void)
void	validateTarget (void)
Private Attributes
boost::shared_ptr < pilot::AccelBase >	accel_
ros::Subscriber	accel_cmd_
boost::shared_ptr < device_interface::DeviceBrake >	brake_
ros::Subscriber	car_cmd_
Config	config_
ros::Time	current_time_
ros::Time	goal_time_
boost::shared_ptr < device_interface::DeviceImu >	imu_
bool	is_shifting_
ros::Subscriber	learning_cmd_
boost::shared_ptr < device_interface::DeviceOdom >	odom_
ros::Publisher	pilot_state_
art_msgs::PilotState	pstate_msg_
boost::shared_ptr< ReconfigServer >	reconfig_server_
boost::shared_ptr < device_interface::DeviceShifter >	shifter_
boost::shared_ptr < device_interface::DeviceSteering >	steering_
boost::shared_ptr < device_interface::DeviceThrottle >	throttle_
ros::Duration	timeout_

Detailed Description

controls the ART vehicle brake, throttle, steering and transmission

The pilot receives CarDriveStamped messages from the navigator, then translates them into commands to the servo motor actuators for controlling the speed and direction of the vehicle. It gets odometry information from a separate node.

Subscribes:

pilot/drive [art_msgs::CarDriveStamped] driving command
pilot/cmd [art_msgs::CarCommand] velocity and steering angle command
imu [sensor_msgs::Imu] estimate of robot accelerations
odom [nav_msgs::Odometry] estimate of robot position and velocity.

brake/state [art_msgs::BrakeState] brake status.
shifter/state [art_msgs::Shifter] shifter relays status.
steering/state [art_msgs::SteeringState] steering status.
throttle/state [art_msgs::ThrottleState] throttle status.

Publishes:

pilot/state [art_msgs::PilotState] current pilot state information.
brake/cmd [art_msgs::BrakeCommand] brake commands.
shifter/cmd [art_msgs::Shifter] shifter commands.
steering/cmd [art_msgs::SteeringCommand] steering commands.
throttle/cmd [art_msgs::ThrottleCommand] throttle commands. Pilot node class.

Definition at line 82 of file pilot.cc.

Member Typedef Documentation

typedef dynamic_reconfigure::Server<Config> PilotNode::ReconfigServer [private]

Definition at line 103 of file pilot.cc.

Constructor & Destructor Documentation

PilotNode::PilotNode ( ros::NodeHandle node )

constructor

Definition at line 142 of file pilot.cc.

Member Function Documentation

void PilotNode::adjustSteering ( void ) [private]

Adjust steering angle.

We do not use PID control, because the odometry does not provide accurate yaw speed feedback. Instead, we directly compute the corresponding steering angle. We can use open loop control at this level, because navigator monitors our actual course and will request any steering changes needed to reach its goal.

Todo:: Limit angle actually requested based on current velocity to avoid unsafe high speed turns.

Definition at line 213 of file pilot.cc.

void PilotNode::halt ( void ) [private]

halt -- soft version of hardware E-Stop.

The goal is to bring the vehicle to a halt as quickly as possible, while remaining safely under control. Normally, navigator sends gradually declining speed requests when bringing the vehicle to a controlled stop. The only abrupt requests we see are in "emergency" stop situations, when there was a pause request, or no clear path around an obstacle.

Note:: The target goal velocity may not always be zero, due to the gear shifting requirements.

Postcondition:: Since this function bypasses the normal acceleration controller, it is reset on exit.

Definition at line 245 of file pilot.cc.

void PilotNode::monitorHardware ( void ) [private]

monitor hardware status based on current inputs

Postcondition:: pstate_msg_ updated to reflect current control hardware status and time of this cycle

Todo:: Optionally check if no commands received recently.

Definition at line 275 of file pilot.cc.

void PilotNode::processCarCommand ( const art_msgs::CarCommand::ConstPtr & msg ) [private]

CarCommand message callback (now DEPRECATED)

Definition at line 329 of file pilot.cc.

void PilotNode::processCarDrive ( const art_msgs::CarDriveStamped::ConstPtr & msg ) [private]

CarDriveStamped message callback

Definition at line 321 of file pilot.cc.

void PilotNode::processLearning ( const art_msgs::LearningCommand::ConstPtr & learningIn ) [private]

LearningCommand message callback (DEPRECATED)

Definition at line 359 of file pilot.cc.

void PilotNode::reconfig	(	Config &	newconfig,
		uint32_t	level
	)			`[private]`

handle dynamic reconfigure service request

Parameters:

	newconfig	new configuration from dynamic reconfigure client, becomes the service reply message as updated here.
	level	SensorLevels value (0xffffffff on initial call)

This is done without any locking because it is called in the same thread as ros::spinOnce() and all the topic subscription callbacks.

Definition at line 377 of file pilot.cc.

void PilotNode::speedControl ( void ) [private]

Speed control

Manage the shifter. Inputs are the current and target states. If a gear shift is requested, the vehicle must first be brought to a stop, then one of the transmission shift relays set for one second (then reset), before the vehicle can begin moving in the opposite direction.

Definition at line 405 of file pilot.cc.

void PilotNode::spin ( void )

main loop

Definition at line 177 of file pilot.cc.

void PilotNode::validateTarget ( void ) [private]

validate target CarDrive values

Definition at line 477 of file pilot.cc.