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PIDMC Class Reference

#include <PIDMC.h>

Inheritance diagram for PIDMC:

Inheritance graph
[legend]
List of all members.

Detailed Description

A nice little MotionCommand for manually manipulating the PID values.

This will, by default, autoprune after its PID values have been set.

Although this doesn't handle directly sending PID commands to the system (the MotionManager::updatePIDs() does that) a little documentation on how Tekkotsu ad OPEN-R handle the PIDs might be nice.

In Tekkotsu, each of P,I, and D are a single floating point number. However, OPEN-R has, in essence, a limited precision floating point number. Each value is broken into a gain (mantissa) and shift (exponent). The shifts appear to be 4 bit values, and are inverted. In other words, x = g/(1<<(0x10-s)), or $ x = \frac{g}{2^{16-s}} $ The gain is probably 6-8 bits of resolution.

On the ERS-2xx series, each joint is completely independent. One caveat is that the shift value 0x0A gives a warning (AGRMSDriver::SetGain() : 0x0A IS USED FOR GAIN SHIFT VALUE.) for some unknown reason.

On the ERS-7, all the joints share the last set shift values, so a global set of shifts must be enforced. This of course, pretty much kills the whole point of having the shifts.

To understand the conversion from Tekkotsu format to the OPEN-R format, see MotionManager::updatePIDs().

A final note: the OPENR::SetJointGain function seems to be a rather costly function call. You should probably try to avoid setting PIDs at too high a frequency.

Definition at line 41 of file PIDMC.h.

Public Member Functions

 PIDMC ()
 Constructor, uses default PIDs and 0 weight for all.
 PIDMC (float powerlevel, float w=1)
 Constructor, sets general power level of all.
 PIDMC (unsigned int low, unsigned int high, float powerlevel, float w=1)
 Constructor, sets general power level of a range of joints, uses default and 0 weight for others.
virtual ~PIDMC ()
 Destructor.
void setDefaults (float weight=1)
 Sets the PIDs to the defaults specified in RobotInfo.
void setJointPowerLevel (unsigned int i, float p, float w=1)
 Sets the PIDs to a percentage of default for a given joint, and sets weight.
void setAllPowerLevel (float p, float w=1)
 Sets the PIDs to a percentage of default for all joints.
void setRangePowerLevel (unsigned int low, unsigned int high, float p, float w=1)
 Sets a range of joints' PIDs to a given power level and weight.
void setPID (unsigned int i, const OutputPID &pid)
 Use this to set the PID value and weight.
OutputPIDgetPID (unsigned int i)
 Use this if you want to double check the PID you set.
const OutputPIDgetPID (unsigned int i) const
 Use this if you want to double check the PID you set.
virtual int updateOutputs ()
 is called once per update cycle, can do any processing you need to change your priorities or set output commands on the MotionManager
virtual int isDirty ()
 not used by MotionManager at the moment, but could be used to reduce recomputation, and you may find it useful
virtual int isAlive ()
 used to prune "dead" motions from the MotionManager
virtual void DoStart ()
 marks this as dirty each time it is added

Static Protected Member Functions

static bool isPID (unsigned int i)
 returns true if the output i is a PID joint

Protected Attributes

bool dirty
 true if there are changes that have not been picked up by Motion
OutputPID PIDs [NumPIDJoints]
 the PIDs being requested


Constructor & Destructor Documentation

PIDMC::PIDMC  )  [inline]
 

Constructor, uses default PIDs and 0 weight for all.

Definition at line 44 of file PIDMC.h.

PIDMC::PIDMC float  powerlevel,
float  w = 1
[inline]
 

Constructor, sets general power level of all.

Definition at line 49 of file PIDMC.h.

PIDMC::PIDMC unsigned int  low,
unsigned int  high,
float  powerlevel,
float  w = 1
[inline]
 

Constructor, sets general power level of a range of joints, uses default and 0 weight for others.

Definition at line 53 of file PIDMC.h.

virtual PIDMC::~PIDMC  )  [inline, virtual]
 

Destructor.

Definition at line 59 of file PIDMC.h.


Member Function Documentation

virtual void PIDMC::DoStart  )  [inline, virtual]
 

marks this as dirty each time it is added

Reimplemented from MotionCommand.

Definition at line 70 of file PIDMC.h.

const OutputPID& PIDMC::getPID unsigned int  i  )  const [inline]
 

Use this if you want to double check the PID you set.

Definition at line 123 of file PIDMC.h.

OutputPID& PIDMC::getPID unsigned int  i  )  [inline]
 

Use this if you want to double check the PID you set.

Definition at line 118 of file PIDMC.h.

virtual int PIDMC::isAlive  )  [inline, virtual]
 

used to prune "dead" motions from the MotionManager

note that a motion could be "paused" or inactive and therefore not dirty, but still alive, biding its time to "strike" ;)

Returns:
zero if the motion is still processing, non-zero otherwise

Implements MotionCommand.

Definition at line 69 of file PIDMC.h.

virtual int PIDMC::isDirty  )  [inline, virtual]
 

not used by MotionManager at the moment, but could be used to reduce recomputation, and you may find it useful

Returns:
zero if none of the commands have changed since last getJointCmd(), else non-zero

Implements MotionCommand.

Definition at line 68 of file PIDMC.h.

static bool PIDMC::isPID unsigned int  i  )  [inline, static, protected]
 

returns true if the output i is a PID joint

Definition at line 129 of file PIDMC.h.

void PIDMC::setAllPowerLevel float  p,
float  w = 1
[inline]
 

Sets the PIDs to a percentage of default for all joints.

Definition at line 88 of file PIDMC.h.

Referenced by PIDMC(), and setDefaults().

void PIDMC::setDefaults float  weight = 1  )  [inline]
 

Sets the PIDs to the defaults specified in RobotInfo.

Definition at line 74 of file PIDMC.h.

Referenced by PIDMC().

void PIDMC::setJointPowerLevel unsigned int  i,
float  p,
float  w = 1
[inline]
 

Sets the PIDs to a percentage of default for a given joint, and sets weight.

Definition at line 79 of file PIDMC.h.

void PIDMC::setPID unsigned int  i,
const OutputPID pid
[inline]
 

Use this to set the PID value and weight.

Definition at line 111 of file PIDMC.h.

void PIDMC::setRangePowerLevel unsigned int  low,
unsigned int  high,
float  p,
float  w = 1
[inline]
 

Sets a range of joints' PIDs to a given power level and weight.

Definition at line 98 of file PIDMC.h.

Referenced by PIDMC().

virtual int PIDMC::updateOutputs  )  [inline, virtual]
 

is called once per update cycle, can do any processing you need to change your priorities or set output commands on the MotionManager

Returns:
zero if no changes were made, non-zero otherwise
See also:
RobotInfo::NumFrames

RobotInfo::FrameTime

Implements MotionCommand.

Definition at line 63 of file PIDMC.h.


Member Data Documentation

bool PIDMC::dirty [protected]
 

true if there are changes that have not been picked up by Motion

Definition at line 133 of file PIDMC.h.

Referenced by DoStart(), isAlive(), isDirty(), PIDMC(), setAllPowerLevel(), setJointPowerLevel(), setPID(), setRangePowerLevel(), and updateOutputs().

OutputPID PIDMC::PIDs[NumPIDJoints] [protected]
 

the PIDs being requested

Definition at line 134 of file PIDMC.h.

Referenced by getPID(), setAllPowerLevel(), setJointPowerLevel(), setPID(), setRangePowerLevel(), and updateOutputs().


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

Tekkotsu v2.2.2
Generated Tue Jan 4 15:45:29 2005 by Doxygen 1.4.0