chrono::models::ChRobotActuation Class Reference

Description

Generic robot actuation driver using interpolated data from files.

ChRobotActuation takes 3 input files, the lines of which contain a time stamp and values for the motor actuations (equal in number to the number of specified motors). The "cycle" input data file is required, while the "start" and "stop" input files are optional. Within each input data file, time stamps are assumed to start at 0. Actuations at the current time are calculated (through linear interpolation within each data set) each time the Update() function is called.

In the most general case, the robot is assumed to go through the following phases:

1. POSE:
   During this phase (of user-specified duration), the actuations are evolved to the initial pose, defined by the
   first line of the "start" dataset (if it exists, otherwise, the "cycle" dataset).
   This is done by interpolation using a logistic function.
2. HOLD:
   During this phase (of user-specified duration), the robot holds the initial pose.
3. START:
   During this phase, the robot assumes the pose necessary for a particular operation mode.
4. CYCLE:
   This is the main operating phase. This phase can be repeated if so indicated.
5. STOP:
   During this phase, the robot assumes a rest end position.

The different input data files are assumed to be consistent with each other (for example, the end of the "start" dataset must match the beginning of a cycle.

#include <ChRobotActuation.h>

Collaboration diagram for chrono::models::ChRobotActuation:

Classes
class	PhaseChangeCallback
	Class to be used as callback interface for user-defined actions at phase changes. More...

Public Types
enum	Phase {   Phase::POSE, Phase::HOLD, Phase::START, Phase::CYCLE,   Phase::STOP }
	Actuation phases. More...
typedef std::vector< double >	Actuation

Public Member Functions
	ChRobotActuation (int num_motors, const std::string &filename_start, const std::string &filename_cycle, const std::string &filename_stop, bool repeat=false)
	Construct a robot actuator using the specified input data files. More...
void	SetVerbose (bool verbose)
	Enable/disable verbose output (default: false).
void	SetDrivingMode (bool drivemode)
	Set the driving mode to accept external inputs (default: false).
void	SetTimeOffsets (double time_pose, double time_hold)
	Specify time intervals to assume and then hold the initial pose (default: 1s, 1s). More...
const Actuation &	GetActuation () const
	Return the current motor actuations.
Actuation &	GetActuation ()
void	SetActuation (Actuation ext_act)
	Directly feed actuations to the motors.
std::string	GetCurrentPhase () const
	Return the current phase.
void	SetPhase (Phase phase)
	Set (force) the phase.
void	RegisterPhaseChangeCallback (PhaseChangeCallback *callback)
	Register a phase-change callback object.
void	Update (double time)
	Update internal state of the robot driver.

Static Public Member Functions
static std::string	GetPhaseAsString (Phase phase)

Protected Member Functions
void	LoadDataLine (double &time, Actuation &buffer)

Protected Attributes
int	m_num_motors
	number of actuated motors
bool	m_verbose
	verbose output
std::ifstream	m_ifs_start
	input file stream for start phase
std::ifstream	m_ifs_cycle
	input file stream for cycle phase
std::ifstream	m_ifs_stop
	input file stream for stop phase
std::ifstream *	m_ifs
	active input file stream
double	m_time_pose
	time interval to assume initial pose
double	m_time_hold
	time interval to hold initial pose
double	m_offset
	current time offset in input files
bool	m_repeat
	repeat cycle
Phase	m_phase
	current phase
double	m_time_1
	time for cached actuations
double	m_time_2
	time for cached actuations
Actuation	m_actuations_1
	cached actuations (before)
Actuation	m_actuations_2
	cached actuations (after)
Actuation	m_actuations
	current actuations
PhaseChangeCallback *	m_callback
	user callback for phase change
bool	m_driven = false
	true if the using external inputs instead of reading from a file

Friends
class	RoboSimian

Member Enumeration Documentation

Phase

enum chrono::models::ChRobotActuation::Phase

strong

Actuation phases.

Enumerator
POSE	from design configuration to an initial pose
HOLD	hold the last configuration
START	from initial pose to operating pose
CYCLE	operation (periodic)
STOP	from operating pose to final pose

Constructor & Destructor Documentation

ChRobotActuation()

chrono::models::ChRobotActuation::ChRobotActuation	(	int	num_motors,
		const std::string &	filename_start,
		const std::string &	filename_cycle,
		const std::string &	filename_stop,
		bool	repeat = false
	)

Construct a robot actuator using the specified input data files.

The data files for the "start" and "stop" phases are not required (pass an empty string).

Parameters

num_motors	number of actuated motors
filename_start	name of file with joint actuations for start phase
filename_cycle	name of file with joint actuations for cycle phase
filename_stop	name of file with joint actuations for stop phase
repeat	true if cycle phase is looped

Member Function Documentation

SetTimeOffsets()

void chrono::models::ChRobotActuation::SetTimeOffsets	(	double	time_pose,
		double	time_hold
	)

Specify time intervals to assume and then hold the initial pose (default: 1s, 1s).

Parameters

time_pose	time to transition to initial pose (duration of POSE phase)
time_hold	time to hold initial pose (duration of HOLD phase)

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The documentation for this class was generated from the following files:

• /builds/uwsbel/chrono/src/chrono_models/robot/ChRobotActuation.h
• /builds/uwsbel/chrono/src/chrono_models/robot/ChRobotActuation.cpp