Easy motor control based on convergent processor BF50x

Motors are used almost everywhere, from elevators and home appliances to robots and industrial automation production lines. As high-energy consuming devices, the huge number of motors consume a high proportion of the world's electricity consumption. In the United States, it is estimated that 50% of electricity is consumed by motors. Due to the low efficiency of many motors, a large part of this huge energy consumption is wasted. For example, the efficiency of small AC motors is as low as 50%.

The low energy efficiency of motors is a double whammy for application environments such as factories - it consumes electricity and generates heat that affects equipment performance. One way to solve this problem is to add intelligent load matching and variable speed control, which can improve energy efficiency by 14% to 30%. If this solution is widely adopted, the United States alone can save 15% of total electricity, which is equivalent to reducing energy consumption by 300 billion kilowatt-hours, saving nearly $15 billion in electricity costs, and reducing greenhouse gas emissions by 180 million tons per year.

The pressure of low-carbon economy has made advanced motor control solutions increasingly valued. More and more motors are beginning to adopt advanced control technologies to achieve the best performance of target applications and reduce power consumption as much as possible. In addition, consumers and relevant government regulations have also put forward more stringent requirements on the energy saving, low noise and safety characteristics of motors, and DSP-based motor control applications are rapidly gaining more and more widespread applications due to their unique advantages.

DSP becomes the preferred solution for high-performance motor control.

Motor control ICs can be divided into three categories, namely, dedicated motor control chips, MCUs and DSPs for motor control applications.

As society pays more attention to environmental protection, the design of low-energy products faces increasingly stringent requirements. Similarly, in recent years, motor control system solutions have also faced increasingly higher requirements. On the one hand, the complex algorithms and advanced modeling used for sensorless vector control require excellent processing capabilities, and on the other hand, they need to have comprehensive advantages in performance, efficiency, ease of use and cost. With the increasing demand for energy saving and product performance in the global market, as well as the continuous decline in prices, the unique advantages of DSP have made it more and more widely recognized in the motor control market, expanding from the high-end industrial motor control field to a wider range of motor control markets.

High-performance motor application systems usually include core servo functions, motion description, and host communication functions. In many MCU or dedicated chip solutions in the past, due to the limited processing power of the processor, the control algorithm must be compromised during system design to release enough performance margin to implement other functions, or a dual-processor solution must be adopted. With the rapid decline in DSP prices, the cost difference between MCU and DSP has narrowed, and DSP solutions have more advantages in reducing the number of components and circuit size, reducing overall BOM cost, and improving system performance.

Embedded DSP motor control chips integrate the DSP core and a series of powerful control peripherals into one chip, so that the high-speed DSP core is used as the computing engine, and the built-in analog-to-digital converter module increases the motor control bandwidth, and allows more complex control and sensorless algorithms to be implemented at low cost, which can control AC induction motors, brushless DC motors and switched reluctance motors. These computing capabilities and optimized peripherals allow DSP to easily complete more functions, such as power factor correction. Without increasing the cost of the controller, it can meet the requirements of certain special applications, such as the balance control of washing machines. High computing power also allows engineers to use algorithms with higher computing intensity, thereby using more efficient motors, further improving efficiency and dynamic performance.

BF50x simplifies motor control design

The launch of the Blackfin BF50x processor is in line with the current motor control market's requirements for processor features and performance, providing a variety of optimized solution options with a combination of features, which will further strengthen the competitive position of DSP in the motor control market. BF50x continues to inherit the advanced signal processing functions unique to the Blackfin processor and the ease of use of general-purpose microcontrollers, providing 400MHz processing performance at the price of processors with an industry-leading frequency of 150-200MHz, achieving breakthrough performance and power efficiency. BF50x well meets the dual functional requirements of signal processing and control in motor control applications, thus eliminating the trouble of having to use two heterogeneous processors in many applications, thereby simplifying software and hardware design. Using the high processing power of the BF50x processor, design engineers can achieve more powerful system functions and accuracy by using complex algorithms, including real-time processing of more data, shortening latency, and achieving higher design flexibility and optimization of system interfaces and control functions.

1. The superior performance of the leading hardware platform

Blackfin BF50x processor enables motor control system design engineers to execute more complex algorithms, ensuring that the system can be dynamically controlled to adapt to real-time changes in system behavior, thereby achieving smoother performance and reducing power consumption. Higher motor control efficiency can be achieved by adopting sensorless vector control, and by using advanced modeling technology to accurately determine the motor position and/or speed, design engineers can omit the position/speed sensor, thereby further reducing costs and improving system reliability.

BF50x implements optimized peripheral integration for motor control applications. Users can select the most cost-effective, performance-intensive, integrated and power-efficient solution for their target applications in this series of products: the optional built-in dual SAR 12-bit ADC (BF506F) enables more accurate data conversion, providing the accuracy required for accurate modeling of the motor state, thereby more accurately estimating the motor position/speed; the on-chip 4MB executable parallel flash memory can be used for program storage, eliminating off-chip memory, thereby reducing system BOM costs and improving reliability; standard features such as the removable storage interface and the CAN controller provide communication interfaces and storage support features in motor control applications... For a more detailed description of product features, please refer to the BF50x data sheet.

2. Significant low-cost advantage

The 400MHz main frequency of the BF50x processor extends high-performance digital signal processing capabilities to a wider range of motor control applications, including applications previously dominated by high-end microcontrollers, while its price once again breaks the low price record of Blackfin processors, with the lowest price quote for 10,000-piece quantities as low as US$4.5. Compared with similarly priced competitive processors with integrated ADC and flash memory, the BF50x performance is improved by more than 100%. In other words, the BF50x is the most cost-effective solution among DSPs with integrated ADC and flash memory, so under the same cost budget, design engineers can obtain great advantages in signal conversion and calculation accuracy by using the BF50x. This performance margin allows design engineers to obtain stronger system functions and accuracy by applying more complex algorithms. The BF50x processor also combines a high-performance signal processing core with industry-standard interfaces to ensure that application development can be completed quickly and economically without the need for high-cost external devices. As mentioned earlier, the BF50x has an optional built-in dual SAR type 12-bit ADI ADC for higher-precision data conversion, as well as an optional 4MB on-chip executable flash memory. All these features minimize off-chip components to reduce overall system hardware cost and design cost.

Independent evaluation agency BDTI's benchmark analysis of Blackfin BF50x's price-performance ratio confirms BF50x's unique advantage over competing devices. Based on the speed-per-dollar ratio of fixed-point processors, BF50x's BDTIsimMark2000/$ score is as high as 498, far exceeding similar processors.

ADI also launched a new low-cost ($199) EZ-KIT Lite evaluation kit for the BF50x series, providing the most economical and affordable option for processor evaluation. The latest ultra-low-cost, high-performance Blackfin emulator ADZS-ICE-100B, which was fully launched in China at the same time, has reduced its price to a new low of $150 for the first time, providing designers with an unprecedented low-cost, high-performance design tool. The cost-effective emulator, combined with other development environments and tools of ADI, will help users simplify the design process, reduce design costs and significantly accelerate time to market.

3. Comprehensive design resource support

In the software development process of the motor control system, the advanced integrated development environment helps design engineers quickly and easily complete software programming and debugging. As mentioned above, while launching BF50x, ADI also launched a low-cost EZ-KIT Lite evaluation kit for the BF50x series, including the ADI VisualDSP++ integrated development and debugging environment (IDDE). ADI's latest ultra-low-cost high-performance emulator ADZS-ICE-100B is fully launched in China and is customized for customers using Blackfin. In addition to the shocking price of as low as $150, the many innovative features of ADZS-ICE-100B also bring a new concept of higher performance and ease of use to JTAG emulators.

When choosing a motor control solution, in order to reduce the difficulty of design and speed up the product launch, it is also necessary to examine whether the solution provider provides strong application support. In order to greatly facilitate engineers to implement motor control applications based on BF50x, ADI began to cooperate with Shanghai Jiaotong University as early as August 2008, and implemented the software and hardware simulation design of BF50x in motor control applications based on BF548 processor. It has successfully completed the hardware platform and software complete solution for three-phase induction motor, brushless DC motor, and permanent magnet synchronous motor control applications based on BF50x, and can provide users with software and hardware design documents and algorithm modules and library resources. The software modules provided include all drivers including general ADC drivers, Hall effect interface drivers (for brushless DC motor control applications using sensors), PWM drivers, etc., as well as various algorithm modules. These hardware reference designs and complete software modules that can be used directly can greatly accelerate the design process of motor control systems and greatly reduce the difficulty and cost of design.

Summary of this article

When choosing a DSP platform for your motor control system, in addition to performance and features, you should choose a supplier with market advantages, long-term stable supply capabilities, and long-term relevant product development strategies. This is very important for OEMs to continue product development, because it involves the reusability of R&D results (including software and hardware). ADI regards industrial applications as one of the most important target markets for its Blackfin processor series, and motor control is a key area of ​​industrial applications. In early 2009, ADI launched a low-cost DSP for applications such as motor control - BF51x, and the launch of BF50x once again refreshed the price of Blackfin processors in a short period of time, while also achieving more performance optimization. The low-cost evaluation kit and simulator supporting products launched at the same time also once again sent a strong signal that ADI will strengthen the development of the motor control application market.