Namespace package_template

namespace package_template

Functions

void print_configuration(const Gains_configuration &configuration)

print values encapsulated by the provided configuration console on the standard output

PID &get_default_pid()

convenience factory for getting default controller, i.e.

same as PID(std::shared_ptr<DefaultConfiguration> configuration)

See also

DefaultConfiguration

class DefaultConfiguration : public package_template::Gains_configuration

#include <default_configuration.hpp>

Default configuration for the kp, kd, ki paramters.

This class initialize the PID gains as follow:

• kp = DEFAULT_KP,

• kd = DEFAULT_KD

• ki = DEFAULT_KI

Public Functions

inline ~DefaultConfiguration()

Here we use the default destructor.

virtual double get_kp() const

Always returns DEFAULT_KP.

Returns:

double DEFAULT_KP

virtual double get_kd() const

Always returns DEFAULT_KD.

Returns:

double DEFAULT_KD

virtual double get_ki() const

Always returns DEFAULT_KI.

Returns:

double DEFAULT_KI

virtual bool has_error() const

Always returns false.

Returns:

true Never

Returns:

false Always

virtual std::string get_error() const

Always returns “no error”.

Returns:

std::string “no error”

class File_configuration : public package_template::Gains_configuration

#include <file_configuration.hpp>

Reading configuration from yaml file.

Public Functions

File_configuration(std::string yaml_file)

Returns error encountered when reading configuration.

See also

has_error()

Parameters:

yaml_file – absolute path to configuration yaml file. The file is expected to have parameters “kp”, “kd” and “ki”

virtual double get_kp() const

Get the proportional gain.

Returns:

double

virtual double get_kd() const

Get the derivative gain.

Returns:

double

virtual double get_ki() const

Get the integral gain.

Returns:

double

virtual bool has_error() const

Enquire if an error was encountered while reading the configuration.

See also

get_error()

Returns:

true if an error has been encountered

Returns:

false otherwise

virtual std::string get_error() const

returns error encountered when reading configuration

See also

has_error()

Private Members

double kp_

Proportinal gain.

double kd_

Derivative gain.

double ki_

Integral gain.

std::string error_message_

Internal error message.

bool error_

True if an error occured.

class Gains_configuration

#include <gains_configuration.hpp>

Abstract class defining for the PID configuration.

This virtual object describes the configuration a PID objects is waiting for. Daughter class will for example be initialize through files, ROS params, etc.

Subclassed by package_template::DefaultConfiguration, package_template::File_configuration, package_template::RosParameters_configuration

Public Functions

inline virtual ~Gains_configuration()

The default destructor do nothing.

virtual double get_kp() const = 0

Get the proportional gain.

Returns:

double

virtual double get_kd() const = 0

Get the derivative gain.

Returns:

double

virtual double get_ki() const = 0

Get the integral gain.

Returns:

double

virtual bool has_error() const = 0

Enquire if an error was encountered while reading the configuration.

See also

get_error()

Returns:

true if an error has been encountered

Returns:

false otherwise

virtual std::string get_error() const = 0

returns error encountered when reading configuration

See also

has_error()

class PID

#include <pid.hpp>

Simple 1D pid controller.

Public Functions

PID()

Construct a default PID object using the DefaultConfiguration.

PID(const Gains_configuration &configuration)

Construct a new PID object using a user provided configuration.

Parameters:

configuration –

~PID()

double compute(const double position, const double velocity, const double position_target, const double delta_time)

compute the force related to the pid controller.

Warning

this function is not stateless, as it performs integration. Call reset_pid() to reset the integral part.

Parameters:

• position – current position

• velocity – current velocity

• position_target – target position

• delta_time – time passed since last measurement. Used for integral computation

Returns:

computed force

void reset_integral()

reset integral part of the PID

Private Members

const Gains_configuration *configuration_

bool private_configuration_

double integral_

class RosParameters_configuration : public package_template::Gains_configuration

#include <rosparameters_configuration.hpp>

Read gains configuration from the ros parameter server.

Public Functions

RosParameters_configuration()

Attempt to get the gains from the parameter server (“gains_kp”,”gains_kd”,”gains_ki” parameters) If roscore is running, calls to this constructor will be blocking until all the gains are read or roscore is turned off.

If roscore is turned off before gains are read, has_error() will return true

See also

has_error()

virtual double get_kp() const

Get the proportinal gain.

virtual double get_kd() const

Get the derivative gain.

virtual double get_ki() const

get the integral gain

virtual bool has_error() const

Check if there are internal errors

virtual std::string get_error() const

Get the error messages

Private Members

double kp_

Proportinal gain.

double kd_

Derivative gain.

double ki_

Integral gain.

std::string error_message_

Internal error message.

bool error_

True is an error occured.