fastcat::ThreeNodeThermalModel Class Reference

Class implementing a Three-Node Thermal Model for estimating internal motor temperatures, through fastcat. More...

#include "three_node_thermal_model.h"

Inheritance diagram for fastcat::ThreeNodeThermalModel:

Collaboration diagram for fastcat::ThreeNodeThermalModel:

Public Member Functions
	ThreeNodeThermalModel ()
	ThreeNodeThermalModel constructor.
bool	ConfigFromYaml (const YAML::Node &node) override
	Parses input yaml file to set model constants and temperature limits.
bool	Read () override
	Reads in most recent temperature and current signal values, and stores them for further calculations.
FaultType	Process () override
	Performs one update step of the thermal prediction model, tracking the most recently predicted temperature values at each node, and reporting a fault if any of the limits are exceeded.
bool	Write (DeviceCmd &cmd) override
	Commands device Currently, only the SEED_THERMAL_MODEL_TEMPERATURE_CMD, used to reseed the model is accepted.
Public Member Functions inherited from fastcat::DeviceBase
virtual	~DeviceBase ()
virtual void	Fault ()
virtual void	Reset ()
virtual void	SetInitializationTime (double time_sec, double monotonic_time_sec)
void	RegisterCmdQueue (std::shared_ptr< ThreadSafeQueue< DeviceCmd > > cmd_queue)
std::string	GetName ()
std::shared_ptr< DeviceState >	GetState ()
void	SetTime (double time, double monotonic_time)
void	SetLoopPeriod (double loop_period)

Protected Attributes
double	thermal_mass_node_1_on_ {0.0}
double	thermal_mass_node_1_off_ {0.0}
double	thermal_mass_node_2_ {0.0}
double	thermal_res_nodes_1_to_2_
	thermal resistance from node 1 to 2 (deg C / W)
double	thermal_res_nodes_2_to_3_
	thermal resistance from node 2 to 3 (deg C / W)
double	winding_res_ {0.0}
	motor winding electrical resistance (ohms)
double	winding_thermal_cor_ {0.0}
	coefficient of resistance
double	k1_ {0.0}
double	k2_ {0.0}
double	k3_ {0.0}
	weights for T4 estimate
std::vector< double >	max_allowable_temps_ {0.0, 0.0, 0.0, 0.0}
uint32_t	persistence_limit_
	be exceeded before throwing a fault
double	ref_temp_ {0.0}
double	exp_smoothing_alpha_ {1.0}
bool	awaiting_seed_temp_ {false}
double	motor_current_
	this value is retrieved from a motor controller measurement
bool	motor_on_status_
	this value is retrieved from the motor controller status
double	motor_res_ {0.0}
std::vector< double >	node_temps_
std::vector< size_t >	node_overtemp_persistences_
Protected Attributes inherited from fastcat::DeviceBase
std::string	name_
	unique device name
double	last_monotonic_time_ = 0.0
double	loop_period_ = 0.0
	only some devices need
double	initialization_time_sec_ = -1
	only some devices need
double	monotonic_initialization_time_sec_ = -1
	only some devices need
bool	device_fault_active_ = false
	device-level fault, manager also has fault status flag
std::shared_ptr< DeviceState >	state_
	Fastcat state data.
std::shared_ptr< ThreadSafeQueue< DeviceCmd > >	cmd_queue_
	for intra-device commands

Static Protected Attributes
static constexpr size_t	FC_TNTM_NUM_SIGNALS = 3
static constexpr size_t	NODE_3_TEMP_IDX = 0
static constexpr size_t	MOTOR_CURRENT_IDX = 1
static constexpr size_t	MOTOR_ON_STATUS_IDX = 2

Additional Inherited Members
Public Attributes inherited from fastcat::DeviceBase
std::vector< Signal >	signals_

Detailed Description

Class implementing a Three-Node Thermal Model for estimating internal motor temperatures, through fastcat.

Constructor & Destructor Documentation

ThreeNodeThermalModel()

fastcat::ThreeNodeThermalModel::ThreeNodeThermalModel

(

)

ThreeNodeThermalModel constructor.

Member Function Documentation

ConfigFromYaml()

bool fastcat::ThreeNodeThermalModel::ConfigFromYaml ( const YAML::Node &  node )

overridevirtual

Parses input yaml file to set model constants and temperature limits.

Parameters

node	The portion of the yaml file corresponding to this device.

Returns

True if configuration completes without error; false otherwise.

Implements fastcat::DeviceBase.

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Process()

FaultType fastcat::ThreeNodeThermalModel::Process ( )

overridevirtual

Performs one update step of the thermal prediction model, tracking the most recently predicted temperature values at each node, and reporting a fault if any of the limits are exceeded.

Returns

FaultType enum value corresponding to appropriate fault state.

Reimplemented from fastcat::DeviceBase.

Read()

bool fastcat::ThreeNodeThermalModel::Read ( )

overridevirtual

Reads in most recent temperature and current signal values, and stores them for further calculations.

Returns

True if device state is read without error; false otherwise.

Implements fastcat::DeviceBase.

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Write()

bool fastcat::ThreeNodeThermalModel::Write ( DeviceCmd &  cmd )

overridevirtual

Commands device Currently, only the SEED_THERMAL_MODEL_TEMPERATURE_CMD, used to reseed the model is accepted.

Parameters

cmd	Command provided to the device, of a type that is a subclass of DeviceCmd

Returns

boolean for if the command was accepted and successful or not

Reimplemented from fastcat::DeviceBase.

Member Data Documentation

awaiting_seed_temp_

bool fastcat::ThreeNodeThermalModel::awaiting_seed_temp_ {false}

protected

this variable is used to delay setting initial temperatures until we read the first temperature for node 3 and sets all nodes to that starting temperature

exp_smoothing_alpha_

double fastcat::ThreeNodeThermalModel::exp_smoothing_alpha_ {1.0}

protected

this parameter specifies the extent to which smoothing is applied to the temperature sensor value

FC_TNTM_NUM_SIGNALS

constexpr size_t fastcat::ThreeNodeThermalModel::FC_TNTM_NUM_SIGNALS = 3

staticconstexprprotected

k1_

double fastcat::ThreeNodeThermalModel::k1_ {0.0}

protected

k2_

double fastcat::ThreeNodeThermalModel::k2_ {0.0}

protected

k3_

double fastcat::ThreeNodeThermalModel::k3_ {0.0}

protected

weights for T4 estimate

max_allowable_temps_

std::vector<double> fastcat::ThreeNodeThermalModel::max_allowable_temps_ {0.0, 0.0, 0.0, 0.0}

protected

motor_current_

double fastcat::ThreeNodeThermalModel::motor_current_

protected

Initial value:

{
      0.0}

this value is retrieved from a motor controller measurement

MOTOR_CURRENT_IDX

constexpr size_t fastcat::ThreeNodeThermalModel::MOTOR_CURRENT_IDX = 1

staticconstexprprotected

motor_on_status_

bool fastcat::ThreeNodeThermalModel::motor_on_status_

protected

Initial value:

{
      false}

this value is retrieved from the motor controller status

MOTOR_ON_STATUS_IDX

constexpr size_t fastcat::ThreeNodeThermalModel::MOTOR_ON_STATUS_IDX = 2

staticconstexprprotected

motor_res_

double fastcat::ThreeNodeThermalModel::motor_res_ {0.0}

protected

this value is estimated based on the temp 1 estimate and represents the resistance of the motor, which is used for calculated power

NODE_3_TEMP_IDX

constexpr size_t fastcat::ThreeNodeThermalModel::NODE_3_TEMP_IDX = 0

staticconstexprprotected

node_overtemp_persistences_

std::vector<size_t> fastcat::ThreeNodeThermalModel::node_overtemp_persistences_

protected

Initial value:

{
      0, 0, 0, 0}

this is used as a counter for how many cycles node 1 has been over the temperature limit

node_temps_

std::vector<double> fastcat::ThreeNodeThermalModel::node_temps_

protected

Initial value:

{
      0.0, 0.0, 0.0, 0.0}

this value is estimated from the model and represents winding temperature

persistence_limit_

uint32_t fastcat::ThreeNodeThermalModel::persistence_limit_

protected

Initial value:

{
      0}

be exceeded before throwing a fault

represents how many time cycles a temperature limit is able to

ref_temp_

double fastcat::ThreeNodeThermalModel::ref_temp_ {0.0}

protected

the reference temperature for the winding resistance parameter, along with being used for calculating the dynamically varying resistance

thermal_mass_node_1_off_

double fastcat::ThreeNodeThermalModel::thermal_mass_node_1_off_ {0.0}

protected

thermal_mass_node_1_on_

double fastcat::ThreeNodeThermalModel::thermal_mass_node_1_on_ {0.0}

protected

thermal_mass_node_2_

double fastcat::ThreeNodeThermalModel::thermal_mass_node_2_ {0.0}

protected

thermal_res_nodes_1_to_2_

double fastcat::ThreeNodeThermalModel::thermal_res_nodes_1_to_2_

protected

Initial value:

{
      0.0}

thermal resistance from node 1 to 2 (deg C / W)

thermal_res_nodes_2_to_3_

double fastcat::ThreeNodeThermalModel::thermal_res_nodes_2_to_3_

protected

Initial value:

{
      0.0}

thermal resistance from node 2 to 3 (deg C / W)

winding_res_

double fastcat::ThreeNodeThermalModel::winding_res_ {0.0}

protected

motor winding electrical resistance (ohms)

winding_thermal_cor_

double fastcat::ThreeNodeThermalModel::winding_thermal_cor_ {0.0}

protected

coefficient of resistance

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

• src/fastcat_devices/three_node_thermal_model.h
• src/fastcat_devices/three_node_thermal_model.cc