Technical Publications
Modeling a Digitally Controlled Power Supply
Power supply designs are going digital. It is now common to see what would have once been a completely analog design incorporate some combination of Digital-Signal Processing (DSP), microcontroller (uC), and/or Field-Programmable Gate Array (FPGA) technologies. This paper illustrates how the SystemVision simulation environment can be used to design and analyze this class of power supply on a 150 W, 100 KHz half-bridge converter.
How to Model Power Systems Using SystemVision
This booklet introduces practical guidelines and specific techniques for developing and analyzing complex power systems with the aid of computer simulation. The general concept of computer simulation (referred to simply as simulation in this booklet) is to use a computer to predict the behavior of a system that is to be developed. To achieve this goal, a system model of the real system is created. This system model is then used to predict actual system performance and to help make effective design decisions.
CAN Bus Signal Integrity Design
VHDL-AMS (IEEE Standard 1076.1) provides hardware modeling capabilities that are well suited for CAN signal integrity analysis. This includes modeling the analog, digital and mixed-signal aspects of the transceivers, as well as the behavior of twisted-pair transmission lines, connectors and other components of the CAN Physical Layer. SystemVision supports both VHDL-AMS as well as traditional Spice modeling methods. This paper presents various modeling approaches applicable to the key hardware components of a CAN bus. It also provides examples of simulation-based techniques for CAN signal integrity design.
Object Action Language Reference Manual
The purpose of this manual is to serve as a reference and general user?s guide to aid in the correct specification of action semantics for UML models. Although originally designed for models used with the BridgePoint UML Suite, the language described can be used to define the action semantics for any UML model in any tool.
The Object Action Language is written to satisfy the following goals:
- Readability - Modelers must be able to easily understand the OAL for development and reviews
- Derivation - Event generation and data access information is captured for derivation of the Object Collaboration Diagrams and Package Dependency Diagrams for both asynchronous (event) and synchronous (data access) communication
- Simulation - The UML models can be simulated through interpretation of the actions
- Translation - Richness of expression is provided while maintaining a specification that can be automatically translated on a target architecture
DO-254 Compliant Design and Verification with VHDL-AMS
The functionality and performance of modern military and aerospace systems has become heavily influenced by their electronic content. Consequently, selecting the right electronic components and choosing the optimal design methodology is vital in developing a successful product. The flexibility and capabilities of new digital components is still growing exponentially. The potential of these devices, however, cannot be fully (and safely) utilized without incorporating the latest design and verification methodologies. Design methodologies for mil-aero applications must consider the complexities of mechatronic systems. The VHDL-AMS language is an undiscovered asset for mil-aero digital designers - a powerful tool to define and verify safety-critical requirements in a non-digital context. This paper discusses the use of VHDL-AMS for safety-critical digital systems.
Lit Number: TECH7810-w
Rules-based Code Generation
There are a number of tools available that aim to improve the software development process by having the developer model the software using the UML. The level of support provided to take the model and turn it into the target implementation varies considerably from no support all the way to full translation of the model and its content. This paper provides an overview of the latter and discusses the numerous benefits of a fully translatable model using a rules-based code generator.
Requirements Tracing
Requirements tracing is accomplished in different ways within different development organizations. This paper describes requirements tracing and one example of its deployment within an engineering team. This process uses common issue tracking and configuration management tools working together with source code editors and UML modeling tools.
Combining ModelSim and Simulink in an Integrated Simulation Environment
Multi-technology system development poses many challenges for conventional design tools. Multi-technology designs are complex because they can incorporate many different technologies within a single system. These systems typically include analog (continuous) and digital (discrete) effects, often spread across several areas of engineering specialization. As a result, such systems are commonly designed and verified with a combination of CAD/CAE tools.
Simulation environments that can directly use such tools as resources for system-level design and verification are essential for two main reasons: 1) to allow the integration of individual components and subsystems into a single, simulatable system, and 2) to allow effective communication and design collaboration among individuals involved in the development of such systems.
This paper discusses one such environment, the SystemVision™ Modeling Solution. SystemVision has the ability to effectively integrate compiled ModelSim libraries, Simulink block diagrams, and additional multi-technology design elements into a single simulatable system. This was demonstrated by developing an Unmanned Aerial Vehicle (UAV) system with the combined power of these tools.
Improving Automotive EE Design with SystemVision
Gaps exist at critical junctures in the design process that work against creation of intelligent automotive electronic systems and networks capable of providing advanced functionality while remaining cost effective, reliable, and durable. Ultimately, encumbrances in the design process lead to systems characterized by quality problems in both hardware and software that are placing a heavy warranty cost burden on manufacturers. This paper illustrates gaps in the design process, discusses their effects on efforts to solve engineering problems, and examines how product quality and cost are affected. Finally, an approach is suggested that enhances control of design processes and improves decision making in view of an understanding of the diverse systems that make up the whole vehicle, while saving time, improving quality, and helping to control costs.
Mini-Baja Traction Control System-Mechatronics Modeling
A versatile new modeling technology was used to help design an innovative traction control system. Using models written exclusively in the IEEE standard VHDL-AMS language, simulation-based analysis and verification were performed at both the component/subsystem and at the overall system levels. Key insights were gained about a wide range of design issues, from the critical need to bleed the brake lines, to power converter topology trade-offs, to detecting inherent wheel lock-up modes in the control algorithm. This paper presents modeling and simulation techniques applicable to a wide range of automotive "mechatronic" systems, where coordinated interaction of mechanical, electronic, and software components is required to meet performance goals.
LVDT/RVDT Sensor Modeling and Signal Conditioning Design
This paper shows how the IEEE Standard 1076.1 (VHDL-AMS) hardware description language was used to create versatile models of LVDT and RVDT sensors. These models can be used to support the design or selection of suitable signal conditioning circuits or algorithms for specific applications. Signal conditioning is a key aspect of LVDT and RVDT sensing systems, with a strong impact on meeting measurement accuracy requirements. In the design example, the effects of a long cable, between a remote LVDT sensor and its associated signal conditioning circuitry, are examined. Measurement error due to cable length and temperature changes, as well as signal conditioning circuit variations, is analyzed. The design process leverages SystemVision's parametric analysis capability to make important signal conditioning and system design trade-offs.