bioscara_hardware_drivers::Gripper Class Reference

Child class implementing control of the hardware gripper. More...

#include <mGripper.h>

Inheritance diagram for bioscara_hardware_drivers::Gripper:

Public Member Functions
	Gripper (float reduction, float offset, float min, float max, float backup_init_pos)
	Construct a new Gripper object.
err_type_t	enable (void) override
	Activates the the hardware.
err_type_t	disable (void) override
	Deactivates the hardware.
err_type_t	setPosition (float width) override
	Sets the gripper width in m.
err_type_t	setServoPosition (float angle)
	Sets the servo position of the gripper actuator in degrees.
Public Member Functions inherited from bioscara_hardware_drivers::BaseGripper
	BaseGripper (float reduction, float offset, float min, float max, float backup_init_pos)
	Construct a new BaseGripper object.
	~BaseGripper (void)
	Destroy the BaseGripper object.
virtual err_type_t	init (void)
	Initializes the gripper.
virtual err_type_t	deinit (void)
	Deinitializes the gripper.
virtual err_type_t	getPosition (float &width)
	Gets the gripper width.
virtual void	setReduction (float reduction)
	Manually set reduction.
virtual void	setOffset (float offset)
	Manually set offset.

Protected Attributes
RPI_PWM	_pwm
	RPI_PWM object to generate PWM voltage for servo control.
int	_freq = 50
	PWM frequency in Hz.
Protected Attributes inherited from bioscara_hardware_drivers::BaseGripper
float	_reduction = 1
	gripper width to actuator reduction ratio
float	_offset = 0
	gripper width position offset
float	_min = 0
	gripper width lower limit
float	_max = 0
	gripper width upper limit
float	_backup_init_pos = 0.0
	Initial position assumed if none can be retrieved from the buffer file.
float	_pos = _backup_init_pos
	stored position
float	_pos_get = _pos
	reported position

Additional Inherited Members
Protected Member Functions inherited from bioscara_hardware_drivers::BaseGripper
err_type_t	save_last_position (float pos)
	Stores the latest position to the buffer file.
err_type_t	retrieve_last_position (float &pos)
	Retrieves the stored position from the buffer file.

Detailed Description

Child class implementing control of the hardware gripper.

Use this class if you wish to control the actual hardware by generating a PWM voltage on GPIO18 of the Raspberry Pi.

Constructor & Destructor Documentation

Gripper()

bioscara_hardware_drivers::Gripper::Gripper	(	float	reduction,
		float	offset,
		float	min,
		float	max,
		float	backup_init_pos
	)

Construct a new Gripper object.

see the BaseGripper constructor for a description of the parameters.

Member Function Documentation

disable()

err_type_t bioscara_hardware_drivers::Gripper::disable ( void  )

overridevirtual

Deactivates the hardware.

Invokes BaseGripper::disable() and stops the servo by disableing the PWM generation.

Returns

err_type_t::OK

Reimplemented from bioscara_hardware_drivers::BaseGripper.

enable()

err_type_t bioscara_hardware_drivers::Gripper::enable ( void  )

overridevirtual

Activates the the hardware.

Invokes BaseGripper::enable() and starts the PWM generation but does not set a position. Must be called before a position is set. The PWM pin is GPIO18 on the Raspberry Pi 4. PWM chip is 0, channel 0.

Returns

err_type_t::OK on success, err_type_t::COMM_ERROR if PWM can not be enabled

Reimplemented from bioscara_hardware_drivers::BaseGripper.

setPosition()

err_type_t bioscara_hardware_drivers::Gripper::setPosition ( float  width )

overridevirtual

Sets the gripper width in m.

Invokes BaseGripper::setPosition(), transforms the desired gripper width to a servo angle using the JOINT2ACTUATOR() macro and finally sets the servo position using setServoPosition()

Parameters

width

width in m.

Returns

see setServoPosition()

Reimplemented from bioscara_hardware_drivers::BaseGripper.

setServoPosition()

err_type_t bioscara_hardware_drivers::Gripper::setServoPosition

(

float

angle

)

Sets the servo position of the gripper actuator in degrees.

Calculates a PWM dutycycle for the desired servo angle and invokes RPI_PWM::setDutyCycle() to set it.

Parameters

angle

in degrees.

Returns

err_type_t::OK on success, err_type_t::COMM_ERROR if the dutycycle can not be set.

Member Data Documentation

_freq

int bioscara_hardware_drivers::Gripper::_freq = 50

protected

PWM frequency in Hz.

_pwm

RPI_PWM bioscara_hardware_drivers::Gripper::_pwm

protected

RPI_PWM object to generate PWM voltage for servo control.

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

• lib/ros2_ws/src/dalsa_bioscara_grippers/bioscara_gripper_hardware_driver/include/bioscara_gripper_hardware_driver/mGripper.h
• lib/ros2_ws/src/dalsa_bioscara_grippers/bioscara_gripper_hardware_driver/src/mGripper.cpp