Icon class icon_class fas fa-quote-left icon_class_computed fas fa-quote-left Related content Figure D.26 - Defining Analyses for Hybrid SUV Engineering Development (Block Definition Diagram) Figure 10-1: Stereotypes defined in SysML ConstraintBlocks package REFERENCE CARD: Types of Block Properties and Block compartments REFERENCE CARD: Property cheat-sheet for Block Source OMG Systems Modeling Language (SysML) 1.6 Copyright information About Object Management Group copyright in text extracts quoted from OMG specifications for educational purposes Snippet kind INFO SysML keywords ConstraintBlock Previous snippet Full quote Constraint blocks provide a mechanism for integrating engineering analysis such as performance and reliability models with other SysML models. Next snippet Constraint blocks can be used to specify a network of constraints that represent mathematical expressions such as {F=m*a} and {a=dv/dt}, which constrain the physical properties of a system. Related snippets Related snippets (backlinks) Constraint blocks can be used to specify a network of constraints that represent mathematical expressions such as {F=m*a} and {a=dv/dt}, which constrain the physical properties of a system. Such constraints can also be used to identify critical performance parameters and their relationships to other parameters, which can be tracked throughout the system life cycle. A constraint block includes the constraint, such as {F=m*a}, and the parameters of the constraint such as F, m, and a. Constraint blocks define generic forms of constraints that can be used in multiple contexts. For example, a definition for Newton’s Laws may be used to specify these constraints in many different contexts. Reusable constraint definitions may be specified on block definition diagrams and packaged into general-purpose or domain-specific model libraries. Such constraints can be arbitrarily complex mathematical or logical expressions. The constraints can be nested to enable a constraint to be defined in terms of more basic constraints such as primitive mathematical operators. Parametric diagrams include usages of constraint blocks to constrain the properties of another block. The usage of a constraint binds the parameters of the constraint, such as F, m, and a, to specific properties of a block, such as a mass, that provide values for the parameters. The constrained properties, such as mass or response time, typically have simple value types that may also carry units, quantity kinds, or probability distributions. A pathname dot notation can be used to refer to nested properties within a block hierarchy. This allows a value property (such as an engine displacement) that may be deeply nested within a containing hierarchy (such as vehicle, power system, engine) to be referenced at the outer containing level (such as vehicle-level equations). The context for the usages of constraint blocks shall also be specified in a parametric diagram to maintain the proper namespace for the nested properties. A constraint block is defined by a keyword of «constraint» applied to a block definition. Properties of this block define parameters of the constraint, with the exception of properties that hold internally nested usages of constraint blocks. The usage of a constraint block is distinguished from other parts by a box having rounded corners rather than the square corners of an ordinary part. A parametric diagram is a restricted form of internal block diagram that shows only the use of constraint blocks along with the properties they constrain within a context. Figure D.26 defines the various model elements that will be used to conduct analysis in this example. It depicts each of the constraint blocks/equations that will be used for the analysis, and key relationships between them. Visit also Visit also (backlinks) Flags
