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Application Notes |
Designing the Next Generation of Industrial Drive and Control Systems
A typical industrial system requires control, application and connectivity capabilities. The control subsystem directly manages motor operation and feedback, the application directs the overall motion, and the connectivity subsystem downloads application, control data and allows the system to be remotely managed.
In general, the core technology that makes up the foundation of each of these subsystems is clearly understood. At the high end, developers continue to innovate new ways to improve overall performance and accuracy. As these technologies mature and the cost to implement them decreases, these solutions that were available for high end ap- plications work their way down the value chain.
The challenge that developers of next-generation systems face today is efficiently implementing incremental innovations to provide better performance with lower latency and greater precision for their target application. To expand market share, they need to deliver better functionality such as new feedback algorithms or novel approaches that improve position accuracy and current sensing at lower costs.
To achieve this, processors offering higher performance and greater integration are required; however, this approach increases development costs and adds system complexities which in turn delay time-to-market and ultimately reduces the competitive advantage of delivering next-generation designs. Implementing new technology must be seamless, simple and value added both to developers and end users.
A New Architecture for Next-Generation Industrial Designs
Many original equipment manufacturers (OEMs) have traditionally relied upon field-program- mable gate-array (FPGA) technology to push leading edge performance of critical functions like torque loop management. FPGAs, however, increase system cost and are difficult to program. In addition, FPGAs offer a relatively fixed implementation that lacks scalability across multiple applications without requiring a redesign.
The dual-core C2000TM DelfinoTM F2837xD MCU from Texas Instruments (TI) makes it
easy to implement various mathematical transforms-and-trig-heavy computations that enable efficient torque loop management in a programmable processor platform. The dual-core Delfino F2837xD is also designed to maximize hardware and software performance for industrial drive and control applications. For example, its fast torque loop calculation can reach sub 3 uS, which is comparable to FPGA implementations.
The F2837xD MCUs extend control loop performance with their fast CPUs further boosted by tightly coupled accelerators. The dual-core MCU is based on TI’s proven C28x CPU. Each CPU core provides 32-bit floating-point processing capabilities at 200 MHz, and dual real- time control accelerators (CLAs) also running at 200 MHz each. Each C28x CPU is augmented by its own Trigonometric Math Unit (TMU) accelerator that provides hardware- based acceleration useful for control-based tasks. These four powerful engines are capable of pounding out the equivalent of 800 MIPS or 1600 MFLOPS of performance enabling consolidation of multi-processor architectures in control loop systems (Figure 1).
For example, in industrial drive applications one CPU (with TMU) + CLA can be used to implement control-side functionality; i.e., the torque loop. The other CPU (with TMU) + CLA can be used to implement the application side of the system; i.e., tracking speed and position, computing trajectories, comparing motion profiles and so on.
This division of the industrial drive system into control and application segments between CPUs provides developers with a clean partitioning to simplify design. Because only control code is running on one of the CPU, it is isolated from application code, thus developers do not need to spend valuable development hours mitigating the potential impact of application code on the responsiveness and latency of real-time tasks (Figure 2).
The Delfino F2837xD MCUs enable developers to migrate high-end functionality down the value chain to mid- and low-range applications. It achieves this through a combination of innovative technologies, including:
- Greater processing capacity at a lower cost than the current solutions
- A streamlined, low-latency architecture that provides higher performance in a deterministic manner
- Advanced hardware-based engines that accelerate common but compute-intensive tasks
- Integration of essential functions into the processor’s architecture to reduce external component count and cost
- Simplified new design migration and reuse of an OEM’s existing code investment
- 180pin controlCARD interface
- All key signals routed through the connector interface
- Can be used in existing 100pin controlCARD EVMs via the TMDSADAP180TO100 adapter
- Built-in Isolated xds100v2 JTAG Emulator
- Option for External JTAG emulator
- UART connectivity via USB
- USB host/device
- ADC clamping