Semiconductors Bring Robots Closer to Humans


Dr. Peter Wawer, Division President of Industrial Power Control at Infineon

Dr. Peter Wawer

Robots have long been the workhorses on the production lines in modern factories. Manufacturers worldwide benefit in terms of increased productivity and cost optimization. Against the background of Industry 4.0 and Smart Factory, the latest generation of industrial robots is revolutionizing traditional production processes. This generation is used as collaborative robots, otherwise known as cobots. They work alongside people, support them in the respective manufacturing processes and increase the quality of the finished products thanks to their highly precise and safe working methods.

 

New Robot Type: Compact, Agile, Safe

Technological advances in the fields of sensor technology, the rapid analysis of vast amounts of data, artificial intelligence and power electronics have made the new generation of robots possible. And the robotics market is undergoing radical change – in addition to the known top dogs, many relatively small start-up companies have appeared on the market and the trend continues. Their focus is to develop special algorithms as a basis for new robot concepts. They do not want to occupy themselves so much with the mechanical design and required electronics hardware.

These specialized new start-up robotics companies are able for example to set up development platforms within a few weeks, on the basis of which robots are developed for use in a wide range of fields. They do not require complex programming for the respective target application like the earlier robot generations. Instead, they can be easily and flexibly reprogrammed and can adapt their motion sequences – sometimes even independently – to new conditions.

There is a broad application field for modern semiconductor products relating to the new generation of robots. The spectrum ranges from motor control, high-performance position and object detection, efficient and compact drives, efficient and compact power supplies and chargers, and the implementation of virtual safety gates to security functions with secure authentication and calibration. Functional safety is not feasible in networked production environments without security. In addition, IP protection, especially for start-up companies whose know-how is based on the algorithms, is essential.

 

Out of the Cage

If you want to liberate robots from their cages, it is necessary to ensure that people do not even come within the critical range of a robot working at high-speed and precision, which could result in them being injured either through their own fault or malfunctions. Designing robots with the corresponding degree of sensitivity is only possible with sophisticated sensor technology.

Basically, it is important to make the area between the person and robot safer, and also between robots themselves. This is about making the protection zones more flexible; i.e. that a greatly reduced protection zone moves along dynamically with a moving robot arm, for example. A zone concept is used when implementing the virtual fences. By way of example, only a warning signal is triggered when approaching in the first warning level, whilst the robot continues to operate at full speed. On approaching further, the speed is then reduced with the corresponding warning. Only in the immediate danger area does the robot stop.

Corresponding protection mechanisms require extremely precise object recognition. Redundant sampling ensures maximum functional safety. It is also helpful to capture the direction of movement – does a person approach and then move away again, or do they enter the danger area? Intelligent detection of the actual danger situation prevents unnecessary downtimes or slowing down of the robot's work – and accordingly production losses and costs.

 

No Safety Without Security

Only in terms of security (data security) are secure systems also functionally safe – an aspect that is increasingly important in the context of Industry 4.0 and IoT. Cryptographic encryption is used to ensure that the robot only performs the functions that it is supposed to do. In particular, the robots as part of the manufacturing process are to be secured against manipulation to permit wired or remote software updates. It also requires secure authentication of users and newly added components.

Calibration is necessary for the correct functioning of the robot. If, for example, a hacker manipulates the calibrations, the robot could then exceed the given limits of movement. This is where security and safety converge – without efficient security protection, there is no functional safety. This is an important requirement for future systems, which is addressed by dedicated security controllers or microcontrollers with features such as the HSM (Hardware Security Module). Since the security functions are implemented in the hardware, users require only little-detailed knowledge of encryption technologies. In addition, the impact on existing software implementations is extremely low!

 

Mobile for Longer

Efficient and compact power supplies and charging functions play an essential role in mobile robots. On the basis of the latest CoolMOS, SiC and GaN technologies, Infineon expects an increase in power density by a factor of 2 to 5 compared to conventional battery chargers, with a shorter charging time for mobile robots. Wireless charging is also possible. The energy can be used even more efficiently if the batteries are recharged via the braking process.

This is made possible by the modern power semiconductors as well as the better use of the batteries in uninterruptible power supplies – for example for buffering energy. Due to the increasing use of battery-powered AGVs in future IE4.0 factories, they could be networked to dramatically reduce the outlay and cost of the additional UPS batteries needed in manufacturing. After all, the batteries of an AGV located at the charging station can be used to some extent for the emergency power supply of the factory's internal supply network.

 

Simplified Wiring

A conventional industrial robot is usually based on a central motor control and numerous drives in the axes. This requires a considerable amount of wiring for a typical robot arm with thick motor cables (3 or more phases) per motor, plus an additional communication bus for control purposes and reading out sensor data.

Thanks to modern semiconductors and the integration of powerline-like modulation together with the motor control electronics, this outlay can be significantly reduced and thus also weight and costs. In laboratory experiments, Infineon has succeeded in reducing the number of cables in a robot arm from almost 30 down to only 2 to 3. At the same time, transmission speeds of well over 100 Mbps were achieved – almost real-time. Less wiring also means fewer interfaces in harsh manufacturing environments, which in turn increases reliability. An initial prototype of such a motor control, for which Infineon integrates the necessary components, is in preparation.

From controllers and power electronics to sensors and chips for safety and security functions, Infineon offers a comprehensive range of components that can be used to realize efficient electronics for the new generation of robots. Additionally, we not only manufacture a comprehensive semiconductor portfolio used in robots but also use various generations of robots in our production lines. Many concepts that are currently being discussed in connection with Industry 4.0 are already in use here. It is obvious that the knowledge of robotics acquired then flows back into the development of the chips.

Source: Bodo's Power Systems, June 2018