Reference¶

Core¶

Core of BMS. All content of this file is imported by bms, and is therefore in bms

This file defines the base of BMS.

class bms.core.Block(inputs, outputs, max_input_order, max_output_order)[source]¶

Bases: object

Abstract class of block: this class should not be instanciate directly

InputValues(it, nsteps=None)[source]¶: Returns the input values at a given iteration for solving the block outputs

OutputValues(it, nsteps=None)[source]¶

Solve(it, ts)[source]¶

class bms.core.DynamicSystem(te, ns, blocks=[])[source]¶

Bases: object

Defines a dynamic system that can simulate itself

Parameters:	te – time of simulation’s end ns – number of steps blocks – (optional) list of blocks defining the model

AddBlock(block)[source]¶: Add the given block to the model and also its input/output variables

DrawModel()[source]¶

PlotVariables(subplots_variables=None)[source]¶

Save(name_file)[source]¶: name_file: name of the file without extension. The extension .bms is added by function

Simulate(variables_to_solve=None)[source]¶

VariablesValues(variables, t)[source]¶

Returns the value of given variables at time t. Linear interpolation is performed between two time steps.

Parameters:	variables – one variable or a list of variables t – time of evaluation

graph¶

bms.core.Load(file)[source]¶: Loads a model from specified file

exception bms.core.ModelError(message)[source]¶

Bases: Exception

args¶

with_traceback()¶: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

class bms.core.PhysicalBlock(physical_nodes, nodes_with_fluxes, occurence_matrix, commands, name)[source]¶

Bases: object

Abstract class to inherit when coding a physical block

class bms.core.PhysicalNode(cl_solves_potential, cl_solves_fluxes, node_name, potential_variable_name, flux_variable_name)[source]¶

Bases: object

Abstract class

class bms.core.PhysicalSystem(te, ns, physical_blocks, command_blocks)[source]¶

Bases: object

Defines a physical system

AddCommandBlock(block)[source]¶

AddPhysicalBlock(block)[source]¶

GenerateDynamicSystem()[source]¶

Simulate()[source]¶

dynamic_system¶

class bms.core.Signal(names)[source]¶

Bases: bms.core.Variable

Abstract class of signal

values¶

class bms.core.Variable(names='variable', initial_values=[0], hidden=False)[source]¶

Bases: object

Defines a variable

Parameters:	names – Defines full name and short name.

If names is a string the two names will be identical otherwise names should be a tuple of strings (full_name,short_name)

Parameters:	hidden – inner variable to hide in plots if true

values¶

Signals¶

Functions¶

Collection of mathematical function signals

class bms.signals.functions.Ramp(name='Ramp', amplitude=1, delay=0, offset=0)[source]¶

Bases: bms.core.Signal

Create a Ramp with a certain amplitude, time delay and offset.

$f(t) = amplitude \times (t - delay) + offset$

Parameters:	name (str) – The name of this signal. amplitude – The angular coefficient of the Ramp function. delay – The horizontal offset of the function. offset – The vertical offset of the function.

values¶

class bms.signals.functions.SignalFunction(name, function)[source]¶

Bases: bms.core.Signal

Create a signal based on a function defined by the user.

Parameters:	name (str) – The name of this signal. function – A function that depends on time.

values¶

class bms.signals.functions.Sinus(name='Sinus', amplitude=1, w=1, phase=0, offset=0)[source]¶

Bases: bms.core.Signal

Create a Sine wave with a certain amplitude, angular velocity, phase and offset.

$f(t) = amplitude \times sin(\omega \times t + phase) + offset$

Parameters:	name (str) – The name of this signal. amplitude – The amplitude of the sine wave. w – The angular velocity of the sine wave ( $\omega$ ). phase – The phase of the sine wave. offset – The vertical offset of the function.

values¶

class bms.signals.functions.Step(name='Step', amplitude=1, delay=0, offset=0)[source]¶

Bases: bms.core.Signal

Create a Step with a certain amplitude, time delay and offset.

$f(t) = amplitude \times u(t - delay) + offset$

where

$u(t) = \begin{cases} 0, & \textrm{if } t < 0 1, & \textrm{if } t \geq 0 \end{cases}$

Parameters:	name (str) – The name of this signal. amplitude – The height of the step function. delay – The time to wait before the function stops being zero. offset – The vertical offset of the function.

values¶

WLTP signals¶

WLTP signals

class bms.signals.wltp.WLTP1(name)[source]¶

Bases: bms.core.Signal

WLTP classe 1 cycle Caution! speed in m/s, not in km/h!

values¶

class bms.signals.wltp.WLTP2(name)[source]¶

Bases: bms.core.Signal

WLTP classe 2 cycle Caution! speed in m/s, not in km/h!

values¶

class bms.signals.wltp.WLTP3(name)[source]¶

Bases: bms.core.Signal

WLTP classe 3 cycle Caution! speed in m/s, not in km/h!

values¶

Blocks¶

Continuous Blocks¶

Collection of continuous blocks

class bms.blocks.continuous.DifferentiationBlock(input_variable, output_variable)[source]¶

Bases: bms.blocks.continuous.ODE

Creates an ODE block that performs differentation of the input relative to time.

$output = \frac{d[input]}{dt}$

Parameters:	input_variable – This is the input or list of inputs of the block. output_variable (Variable) – This is the output of the block.

Evaluate(it, ts)¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

LabelConnections()¶

OutputMatrices(delta_t)¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.continuous.Division(input_variable1, input_variable2, output_variable)[source]¶

Bases: bms.core.Block

Defines a division between its inputs.

$output = \frac{input1}{input2}$

Parameters:	input_variable1 (Variable) – This is the first input of the block, the dividend. input_variable2 (Variable) – This is the second input of the block, the divisor. output_variable (Variable) – This is the output of the block, the quotient.

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

LabelConnections()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.continuous.FunctionBlock(input_variable, output_variable, function)[source]¶

Bases: bms.core.Block

This defines a custom function over the input(s).

$output = f(input)$

Parameters:	input_variable – This is the input or list of inputs of the block. output_variable (Variable) – This is the output of the block. function – This is the function that takes the inputs and returns the output.

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

LabelConnections()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.continuous.Gain(input_variable, output_variable, value, offset=0)[source]¶

Bases: bms.core.Block

Defines a gain operation.

$output = (value \times input) + offset$

Parameters:	input_variable (Variable) – This is the input of the block. output_variable (Variable) – This is the output of the block. gain – This is what multiplies the input. offset – This is added to the input after being multiplied.

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

LabelConnections()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.continuous.IntegrationBlock(input_variable, output_variable)[source]¶

Bases: bms.blocks.continuous.ODE

Creates an ODE block that performs integration of the input over time.

$output = \int_{0}^{t} input\ dt$

Parameters:	input_variable – This is the input or list of inputs of the block. output_variable (Variable) – This is the output of the block.

Evaluate(it, ts)¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

LabelConnections()¶

OutputMatrices(delta_t)¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.continuous.ODE(input_variable, output_variable, a, b)[source]¶

Bases: bms.core.Block

Defines an ordinary differential equation based on the input.

a, b are vectors of coefficients so that H, the transfer function of the block, can be written as:

$H(p) = \frac{a_i p^i}{b_j p^j}$

with Einstein sum on i and j, and p is Laplace’s variable.

For example, a=[1], b=[0,1] is an integration, and a=[0,1], b=[1] is a differentiation.

Parameters:	input_variable (Variable) – This is the input of the block. output_variable (Variable) – This is the output of the block. a – This is the a vector for the transfer function. b – This is the b vector for the transfer function.

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

LabelConnections()[source]¶

OutputMatrices(delta_t)[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.continuous.Product(input_variable1, input_variable2, output_variable)[source]¶

Bases: bms.core.Block

Defines a multiplication between its inputs.

$output = input_1 \times input_2$

Parameters:	input_variable1 (Variable) – This is the first input of the block, one factor. input_variable2 (Variable) – This is the second input of the block, another factor. output_variable (Variable) – This is the output of the block, the product.

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

LabelConnections()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.continuous.Subtraction(input_variable1, input_variable2, output_variable)[source]¶

Bases: bms.core.Block

Defines a subtraction between its two inputs.

$output = input_1 - input_2$

Parameters:	input_variable1 (Variable) – This is the first input of the block, the minuend. input_variable2 (Variable) – This is the second input of the block, the subtrahend. output_variable (Variable) – This is the output of the block, the difference.

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

LabelConnections()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.continuous.Sum(inputs, output_variable)[source]¶

Bases: bms.core.Block

Defines a sum over its inputs.

$output = \sum{input_i}$

Parameters:	input_variable (list[Variables]) – This is the list of inputs of the block. output_variable (Variable) – This is the output of the block.

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

LabelConnections()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.continuous.WeightedSum(inputs, output_variable, weights, offset=0)[source]¶

Bases: bms.core.Block

Defines a weighted sum over its inputs.

$output = \sum{w_i \times input_i}$

Parameters:	input_variable (list[Variables]) – This is the list of inputs of the block. output_variable (Variable) – This is the output of the block. weights – These are the weights that are multiplied by the elements of the input. offset – This offset is added to the final result.

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

LabelConnections()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

Non-linear Blocks¶

Collection of non-linear blocks

class bms.blocks.nonlinear.Coulomb(input_variable, speed_variable, output_variable, max_value, tolerance=0)[source]¶

Bases: bms.core.Block

Return coulomb force under condition of speed and sum of forces (input)

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.nonlinear.CoulombVariableValue(external_force, speed_variable, value_variable, output_variable, tolerance=0)[source]¶

Bases: bms.core.Block

Return coulomb force under condition of speed and sum of forces (input) The max value is driven by an input

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.nonlinear.Delay(input_variable, output_variable, delay)[source]¶

Bases: bms.core.Block

Simple block to delay output with respect to input.

Parameters:	delay – a delay in seconds

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

Label()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.nonlinear.RegCoulombVariableValue(external_force, speed_variable, value_variable, output_variable, tolerance=0)[source]¶

Bases: bms.core.Block

Return coulomb force under condition of speed and sum of forces (input) The max value is driven by an input

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.nonlinear.Saturation(input_variable, output_variable, min_value, max_value)[source]¶

Bases: bms.core.Block

Defines a saturation block.

$output = \begin{cases} min\_value, & \textrm{if } input < min\_value max\_value, & \textrm{if } input > max\_value input, & \textrm{if } min\_value \leq input \leq max\_value \end{cases}$

Parameters:	input_variable (Variable) – This is the input of the block. output_variable (Variable) – This is the output of the block. min_value – This is the lower bound for the output. max_value – This is the upper bound for the output.

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶

class bms.blocks.nonlinear.Sign(input_variable, output_variable)[source]¶

Bases: bms.core.Block

Defines a sign operation on the input.

$output = \begin{cases} -1, & \textrm{if } input < 0 0, & \textrm{if } input = 0 1, & \textrm{if } input > 0 \end{cases}$

Evaluate(it, ts)[source]¶

InputValues(it, nsteps=None)¶: Returns the input values at a given iteration for solving the block outputs

LabelBlock()[source]¶

OutputValues(it, nsteps=None)¶

Solve(it, ts)¶