Industry trends in servo drives: Creating new quality with Melservo J5 Part 1
23.04.202510 min read
Industry is a place of constant development and evolution, and one of the key elements of this process is motion control solutions, in particular servo drives. Servo systems are an integral part of advanced, modern machines and devices that ensure precise control and efficiency in operation.
The future of servo drives – challenges and innovations (Part 1/2)
In this article, we highlight the leading trends in drive solutions and explain how Mitsubishi Electric is responding to these changes with the introduction of its latest MR-J5 servo series. We explain how new technologies are redefining performance and safety standards in industry and what advantages they offer machine manufacturers and users. Finally, you will learn why servo drives play a central role in the future of industry and why it is worth taking a closer look at the solutions on offer in order to remain competitive.
Each industry trend is described in a separate chapter. The first part of the article consists of the following sections:
Higher precision and shorter reaction times
Improved machine and plant safety
Flexibility through open network connections (Servo Open Network)
Compact design for space-saving constructions
The future of servo systems: an overview of the most important industry trends
Higher precision and shorter reaction times
The main goal of every industrial machine engineer is usually clear: maximum productivity at minimum cost. This is an understandable approach, because the faster a machine runs, the higher the production and thus the profit for the company. Increasing competition from companies specializing in machine manufacturing is leading to increased demand for efficiency. This phenomenon is reflected in the demand for servo drive systems. According to a study by Interact Analysis, the industry is expected to grow by 21.6% worldwide in 2021 and by 9.1% in 2022. Average annual growth of 5.5% is expected in the following years.
Mitsubishi Electric is aware of this trend. That is why the Melservo J5 series offers some of the most competitive solutions when it comes to drive efficiency. However, when talking about efficiency, the first question that arises is how this efficiency can be measured. One of the most important factors influencing efficiency is the response time of the drive.
The frequency response is a measure of the time required by the servo drive to process input signals.
Shorter response times enable better precision and performance of the drive unit, with the MR-J5 series offering the fastest frequency response on the market at 3.5 kHz – any change can be made 3,500 times per second. However, it is important to note that the response time within the drive alone does not mean that we are able to change the motion command within the same range, as we are limited by the network through which the data exchange takes place. With CC-Link IE TSN, we can exchange information between the drive and the PLC cyclically every 32.5 microseconds, so the network interface is not a limitation for the drive, as we already know that the performance of the machine is influenced by the latency of the network and the drive itself. Another important consideration is the motor itself as the drive. After all, it is the motor that has to do the actual work. The MR-J5 series uses a motor solution in the form of a synchronous servo motor.
Other manufacturers of servo motors use similar technologies, but our patented winding technology sets us apart. It enables a particularly compact design that not only saves space but also provides a decisive performance advantage. The performance of a servo motor can be illustrated particularly clearly by a key parameter: the power rating. This can also be expressed mathematically:
The power rating describes how quickly a servo motor can accelerate and decelerate – in other words, its dynamic performance. It is calculated as the ratio of the square of the rated torque to the moment of inertia and is a key benchmark for the performance of modern drive technology. The higher the power rating, the more agile and precise the motor will be in demanding applications.
The graph clearly shows that our drive solution is on average up to 20% more efficient than other solutions. This is the result of more than 40 years of experience in servo design.
The graph shows the failure rate of a battery used to store the absolute position of the servo motor.
Another component that determines the performance of the servo amplifier is the encoder. Each motor in the MR-J5 series has a 26-bit encoder (67,108,864 pulses per revolution).
The high resolution of the encoder enables precise positioning, and the battery-free position retention ensures that the absolute position is stored and less wear (e.g., battery replacement) occurs.
Improved machine and plant safety
Safety in industrial plants is a fundamental issue, both for employees and for the company itself. Machine manufacturers and end users are subject to much stricter requirements today than they were just a few years ago. It is not always possible to enclose the entire machine and thus restrict contact with the user to service cases. Increasingly, people have to work together with an application—and this requires suitable safety solutions.
The MR-J5 series recognizes the importance of this issue and introduces decisive changes to the safety concept. Each servo drive in the series is equipped as standard with up to 10 SIL safety functions in accordance with IEC 61508, these include, for example:
STO (Safe Torque Off)
SS1 (Safe Stop 1)
SS2 (Safe Stop 2)
SOS (Safe Operating Stop)
SBC (Safe Brake Control)
SLS (Safely-limited Speed)
SSM (Safe Speed Monitoring)
SDI (Safe Direction)
SLI (Safely-limited Increment)
SLT (Safely-limited Torque)
Functions such as Safe Torque Off or Safe Stop 1 are widely used and well known, but it is also worth considering less obvious safety functions. One example is Safely Limited Torque, which allows a safe torque limit to be set to prevent injuries – for example, if the user's hand is pressed down onto the drive. In addition, higher SIL categories can be achieved by using motors with an additional safety encoder (also available in the MR-J5 series).
The high safety requirements in the servo market have created another need: the transmission of safety signals via industrial networks. The MR-J5 drives are also equipped with this function as standard. Safety signals can be activated not only via Mitsubishi Electric's own network – CC-Link IE TSN – but also via other networks (e.g. with standard FSoE via the EtherCAT network), as explained later in this article.
Example connection diagram for safety devices in the CC-Link IE TSN network:
Flexibility through open network connections (Servo Open Network)
A dynamic industrial environment in which efficiency and flexibility are among the most important challenges is increasingly leading to the need to use different communication protocols and networks in a single machine. As more and more manufacturers come onto the market with powerful solutions, it is becoming virtually impossible to limit oneself to just one network interface in many applications.
The Servo Open Network approach opens up new possibilities and offers greater freedom in the design and integration of industrial machines and systems.
The choice of the right network often depends on the specific application, bandwidth requirements, response times or (especially in recent years) the availability of devices on the market. The MR-J5 series fulfills these requirements by supporting multiple network protocols.
In addition to supporting CC-Link IE TSN, our servo drives also offer full compatibility with the EtherCAT protocol. What does this mean?
Full support for EtherCAT controllers: The MR-J5 can be seamlessly connected to EtherCAT-capable motion controllers. This enables, for example, the complete synchronization of drives within the network with a cycle of 125 µs. Compatibility with the CiA402 drive profile standard enables compatibility with the rest of the network and facilitates programming through PLCopen compatibility.
Compatibility with the communication functions CoE, FoE, EoE, i.e. CANopen over EtherCAT, File over EtherCAT and Ethernet over EtherCAT. Each of the protocols enables the use of different network functionalities such as file transfer or data transmission, e.g. for diagnostic purposes. The MR-J5 series also finds additional applications for these protocols that are often not supported by drive manufacturers with EtherCAT, such as the ability to invoke autotuning of servo drives over the network (enabled by EoE compatibility).
Compatibility with Fail Safety over EtherCAT (FSoE): As mentioned in the previous chapter, machine and plant safety is a priority in the industry. The MR-J5 offers support for FSoE functionality, allowing functional safety to be used directly via EtherCAT. This opens the door to advanced monitoring and emergency stop functions integrated into our drive series without the need for a physical signal connection.
In modern industry, there is a growing demand for more compact machine solutions that take up less space in production. Space requirements play a particularly important role in control cabinet design, as more and more companies are striving to make optimum use of the space available. One important way of achieving this goal is to use multi-axis drive solutions, which allow several axes to be controlled with just one drive. This solution not only reduces the installation space required, but also increases flexibility when integrating the drive systems into the existing infrastructure.
The MR-J5 series servo drives have been designed to ensure that the drive unit takes up as little space as possible.
Space requirements in the control cabinet can be reduced by using multi-axis amplifier solutions (for smaller applications) or common DC bus systems. When using 3-axis amplifiers, space savings in the control cabinet can be up to 40% compared to a standard solution.
The use of common DC bus systems such as the MR-J5D enables even greater space savings due to the modularity of the devices and the availability of 2- and 3-axis amplifiers within the system. The 50% reduction achieved by this solution makes it possible to accommodate twice the number of drives in a single control cabinet, thereby halving its size.
In addition, the use of MR-J5D series drives means further savings in control cabinet size. Since only one power supply (energy recovery inverter) is required for the entire system, the number of protective devices is reduced to those installed upstream of the power supply.
A smaller control cabinet is undoubtedly a major advantage, but space in the application's working area is often limited. How can this problem be solved? Simply install smaller drives! The motors in the MR-J5 series are up to 40 percent shorter than comparable solutions on the market. The coil and encoder technology used has resulted in some of the most compact solutions available.
Our particularly compact servo motors (U types) are used in applications where there is little space available for mounting the drive. In addition, their increased rotor diameter gives them a higher moment of inertia, meaning that in some cases they can be used without a mechanical gear, further reducing the space required.
Still not enough space? Fortunately, the motors in the MR-J5 series are equipped with a single connector, so only one cable is required. This significantly reduces the amount of wiring in the machine and also shortens and simplifies the installation process.
Comparison of motor lengths from the Mitsubishi Electric portfolio, from top to bottom: HG-KR from the previous MR-J4 servo series, HK-KT and HK-KT_U from the MR-J5 series.
Download the flyer here to find out more about the MELSERVO MR-J5 Servo Motion System. Discover the advanced servo technology with AI-based maintenance, high-performance amplifiers and seamless network integration for maximum precision and efficiency.
Download the flyer here to find out more about the MELSERVO MR-J5 Servo Motion System with EtherCAT. Discover Safety over EtherCAT (FSoE), high-performance servo amplifiers and precise servo motors for maximum efficiency and flexibility in your production.
Download the flyer here to find out more about the advantages of Servo Open Network and the flexible usability of the MELSERVO MR-J4 servo series. Get detailed information on the seamless integration of open network connections and how to optimise your production processes.
Part 2 – Industry trends in servo drives: Read now
In the second part of our blog series, we take a look at other key challenges facing modern servo drives. The MR-J5 series from Mitsubishi Electric shows how current industry trends such as
limited warranty and support periods offered by manufacturers,
rising energy prices and legal requirements, as well as
unplanned maintenance downtime and high maintenance costs
with backward compatibility, energy-efficient functions and AI-supported maintenance (predictive maintenance).
