✨Acausal Blocks

Acausal modeling is often used for modeling the dynamics of physical systems. In contrast to Causal blocks, Acausal blocks generally do not have explicit inputs and outputs. Some of the blocks listed here are meant to bridge between the Causal and Acausal domains, and so their ports are a mix of directional and non-directional.

The Acausal Blocks in our Library are divided into domains as follows:

Electrical

For modeling electrical components, voltages, and currents.

Battery

Behaves like an electro-chemical battery cell. Electrical current is integrated to track SOC. Open Circuit Voltage (OCV) is a linear function of SOC between OCV_min and OCV_max. Terminal voltage is OCV minus the voltage drop across the internal resistance.

Capacitor

Behaves like an electrical capacitor.

CurrentSensor

Measures the current flowing through it.

CurrentSource

Source block where current flowing through it is set by an input signal.

Ground

Defines the ground of the electrical circuit, the absolute reference for all other voltages.

IdealMotor

Converts electrical power to mechanical rotational power. The behavior is similar to a permanent magnet motor. Torque is proportional to electrical current.

Inductor

Behaves like an electrical inductor.

Resistor

Behaves like an electrical resistor.

VoltageSensor

Measures the voltage between two points in an electrical circuit.

VoltageSource

Source block where voltage across its electrical terminals is set by an input signal.

Rotational

For modeling mechanical components that are characterized primarily by rotational motion.

Damper

Behaves like a rotational damper.

FixedAngle

Acts like a fixed reference point in the rotational degree of freedom.

IdealGear

A gear ratio between two rotating shafts. When the ratio is >1, the output rotates faster, and has less torque relative to the input.

IdealPlanetary

A planetary gear device with ring gear, sun gear, and planet carrier. The device has three rotational interfaces that need to be connected. The ratio parameter 'r' is the ratio of ring teeth to sun teeth.

IdealWheel

Converts rotational power to translational power. Torque at the shaft input is converted to translational force. Behaves like an idealized version of an automobile wheel.

Inertia

Behaves like a rotational inertia with one rotational degree of freedom.

MotionSensor

Measures the motion at some point of a rotational domain system. Can measure angle, and/or angular velocity, and/or angular acceleration.

SpeedSource

Source block where the speed difference between its ports is set by an input signal.

Spring

Behaves like a rotational spring.

TorqueSensor

Measures the torque across it.

TorqueSource

Source block where the torque across its port is set by an input signal.

Thermal

For modeling thermal properties of components, thermal transfer, and thermal resistance.

HeatCapacitor

Like a thermal mass, stores and release thermal energy as a function of the temperature difference at its thermal interface. It releases thermal energy when its internal temperature is greater then that at its interface, and accumulates thermal energy when its internal temperature is lesser.

HeatFlowSensor

Measures the heat energy flowing through it.

HeatFlowSource

Source block where the heat flow from it is set by an input signal.

TemperatureSensor

Measures the relative temperature between its ports.

TemperatureSource

Source block where the temperature difference between its ports is set by an input signal.

ThermalInsulator

Behaves like a thermal insulator. The heat flow power through the insulator is proportional to the tempertaure difference across the insulator.

Translational

For modeling mechanical components that are characterized primarily by translational motion.

Damper

Behaves like a translational damper.

FixedPosition

Acts like a fixed reference point in the translational degree of freedom.

ForceSensor

Measures the force across it.

ForceSource

Source block where the force across its port is set by an input signal.

Mass

Behaves like a mass with one translational degree of freedom.

MotionSensor

Measures the motion at some point of a translational domain system. Can measure position, and/or velocity, and/or acceleration.

SpeedSource

Source block where the speed difference between its ports is set by an input signal.

Spring

Behaves like a translational spring.