Smart hydraulic cylinders with integrated sensors for real-time performance monitoring

Hydraulic cylinders are among the most important parts of industrial machinery, mobile equipment, and manufacturing processes. They provide the linear force and motion to do all the heavy lifting in machines such as excavators, presses, cranes, landing gear for aircraft, farm equipment, and many other applications. The traditional hydraulic cylinder has been a passive part; it reacts to the fluid pressure and mechanically connects/disconnect but gives no information about its operation until something fails.

But that is changing rapidly as we now have a new generation of smart hydraulic cylinders that contain built-in sensors to provide real-time performance measurements, predictive diagnostics, a higher level of safety for operators, and improved efficiency for operations. In this article, we will discuss the different types of smart hydraulic cylinders, how they function, why they are important, and what will become of hydraulics and industrial automation in the future.

What are intelligent hydraulic cylinders?

Smart hydraulic cylinders are traditional hydraulic cylinders that have been enhanced with embedded sensing and communication technology. The embedded sensors continuously provide data about critical performance parameters, including position, load, temperature, pressure, vibration, and speed, to a computer system via a communication network for analytical purposes. 

Smart hydraulic cylinders provide direct, real-time, genuine data about their own performance and operating environment, unlike traditional hydraulic cylinders, which only indirectly provide data about performance through the performance of the external system or perform periodic manual assessments of hydraulic cylinders.

What are the Key Types of Integrated Sensors Within Intelligent Hydraulic Cylinders and What Do Each of These Sensors Measure?

Intelligent hydraulic cylinders incorporate a collection of integrated sensors. Below are the most prevalent types of sensors found within intelligent hydraulic cylinders and their respective functions:

Position sensors

The position sensor measures the position of the piston rod at all times by utilizing a variety of technologies, such as linear potentiometers, magnetostrictive transducers, and optical encoders.

Key benefits of position sensors include:

• Providing accurate motion control
• Monitoring the full stroke of the piston rods
• Providing feedback to automation systems.

Temperature sensors

Integrated temperature sensors are used to monitor the temperature of the hydraulic oil in the hydraulic cylinders continuously because the temperature of the hydraulic fluid in the hydraulic cylinders directly affects performance, viscosity, efficiency, and wear.

Key benefits of temperature sensors include:

• Providing overheat protection
• Improved thermal management
• Providing early warning of lubrication-related problems.

Pressure sensors

Hydraulic cylinders and systems are measured by their internal force or pressure to determine the load on the machine and whether a leak or pressure surge has occurred.

Advantages of Smart Cylinder Technology

• Gaining information about loads
• Identifying leaks
• Identifying hazards

Vibration and shock sensors

The use of accelerometers and vibration sensors can detect unusual conditions like impact load, misalignment, or accidental contact.

Advantages of Smart Cylinder Technology

• Identifying mechanical stress
• Preventing structural failure
• Notifying of sudden failure

Strain gauges

A strain gauge measures how much deformation has occurred in the cylinder structure, thus determining the possible amount of stress within the machine and whether it is on the verge of failure.

Advantages of Smart Cylinder Technology

• Identifying fatigue and wear
• Improving service schedules
• Preventing catastrophic failure

How smart cylinders operate, data flow, and connectivity

Not only do Smart cylinders collect data, but they also send data (via communication) to other devices that use that information. Each Smart Cylinder has several components that implement this communication, such as:

• Sensors (embedded in the component), which acquire "real-time" physical data
• Microcontroller or Edge Processor, which pre-processes sensor data and filters out noise or performs initial fault detection
• Communication Interface: (wireless: for example, Bluetooth, WiFi, LoRaWAN, or physical communication, i.e., CANbus, Ethernet) that connect to other computers
• A platform (either Cloud or an On-premise platform) that centralizes and analyzes the data by using dashboards, machine learning algorithms, and integration with other industrial systems, such as PLCs and SCADAs.

Through connectivity, we create a stream of data allowing us to both analyze how things are going right now and look back at what has happened to see if we can identify specific trends to help us avoid problems in the future, as opposed to waiting until something happens before trying to figure out how to fix it.

Advantages of real-time performance monitoring and performance analysis

So what’s the big deal about having smart hydraulic cylinders? Here are the main advantages they give us:

1)Hardware maintenance based on real-time data means predictive maintenance of our equipment and will ultimately cut down on our unanticipated breakdowns - predict and act before something bad happens (i.e., detect and repair a leak before it turns into a major problem, identify unusual wear characteristics in our cylinders, forecast future service needs based on historical trend analysis).

As a result, we will reduce unplanned downtime, improve the reliability of our equipment, and reduce our overall lifecycle costs.

2)Smart hydraulic cylinders also help create safer working environments for our employees by providing timely alerts when there is an excessive amount of hydraulic pressure and/or an over- temperature condition, causing a hydraulic system to potentially go beyond design limitations.

Smart cylinders will automatically shut down a hydraulic system should an unsafe state develop, and they will also provide an early warning of structural fatigue before total structural failure.

Safe workplace = safe employees + resilient equipment.

3)The ability to collect data about the performance of a machine in real-time allows for smarter control over how to tune the machine across all systems.

Operators can:

Change a load profile to increase efficiencies

Increase the accuracy of cycle-time data

Improve energy consumption by varying the operation of a cylinder based on demand.

When smart cylinders are integrated into the control systems, they become active participants in the optimization process and not simply passive components.

4)Traditional hydraulic systems typically do not provide operators with any sort of visibility into their operation. As a result, operators and engineers must rely on indirect methods such as gauging pressure, motor amperage, or using their sense of feel to infer the performance of a hydraulic cylinder.

By providing visibility through dashboards/alerts, trend analytics, and remote diagnostics, smart cylinders provide insight to engineers who can then make educated decisions, reduce the amount of guesswork, and streamline the process of troubleshooting.

Smart hydraulic cylinders are currently proliferating throughout many different industries today, with a couple of examples including:

Construction & heavy equipment

Many excavators, loaders, and cranes utilize smart cylinders for boom position, load dynamics, and stress levels on a job site to reduce wear and improve job site safety.

Manufacturing automation

Presses, forging machines, and stamping lines utilize smart cylinders to receive precise feedback on their motion and to monitor their condition, which ultimately allows them to maintain tolerances and produce products at planned rates (throughput).

Harvest and agricultural machinery

Implementers like tractors, harvesters, and balers use real-time data to adjust the hydraulic system based on soil conditions, load, and performance objectives.

Aerospace and defence

Aircraft require highly reliable performance in terms of landing gear, control surfaces, and actuators. Smart cylinders enable monitoring of critical operational and maintenance parameters.

Marine and offshore

Stabilizers, cranes, and winches operate in extreme environments. Sensor feedback minimises the chances of failure when operating under environmentally challenging or remote conditions.

Challenges and considerations

Even if smart hydraulic cylinders provide many advantages, implementing them presents some difficulties:

Data integration & infrastructure- Installing smart cylinders is dependent on having a properly connected network (network hardware, gateways, and platform integration). If installing with legacy systems, this may mean some substantial up-front investments.

Security & reliability- Since the connected sensors need to be secure from cyber attacks, having secure communication protocols, encryption, and authentication is extremely important.

Data management- When using high-frequency data collection using the sensors, large volumes of data can build up quickly; effective filtering, pre-processing, and storing procedures will need to be put in place in order not to end up with information overload.

Compatibility with existing systems- To support the use of IoT-enabled cylinders, the smart cylinders will need to communicate with PLC, SCADA, and control logic. It may be necessary to create custom protocols or to utilize middleware to bridge the gap between new IoT-enabled systems and older industrial controls.

Emerging trends and technologies

Smart hydraulics is constantly developing. Some current trends to pay attention to include:

Analytic algorithms using artificial intelligence

Advancements in Analytics through Machine Learning will provide an unprecedented level of forethought to prevent cylinder failures weeks in advance by analyzing minute details regarding cylinders.

Edge computing technology

When described as "edge computing", this new technology allows analytics to be performed within a cylinder at its location in the field rather than sending data to the cloud, which will help reduce latency as well as reduce bandwidth used.

Digital twins

Digital Twins for hydraulic systems, a representation of hydraulic components in the digital realm that act like hydraulic components in the real world, are now the norm for:

Running simulations before utilizing hydraulic equipment, improving hydraulic system controls, and providing real-time data for improved and accurate planning for maintenance.

Standardization of industrial IoT communications protocols

Protocol standards such as OPC UA, MQTT, and Time-Sensitive Networking (TSN) create a seamless method of connecting smart cylinders to complete industrial automation ecosystems.

How to begin using the smart cylinders application in your business

Here is some information on how you can get started using smart cylinders in your production facility:

Establish A user's requirements

Identify which areas of your operation require real-time monitoring. Will it help to improve the availability of production equipment, improve safety, or optimize process performance?

Identify the appropriate sensors

Different applications may require varying types of sensors. Depending on the specific requirements of the use case being monitored, a higher or lower priority may be assigned to the position, pressure, temperature, and vibration sensors.

Establish a connectivity architecture

Determine the best (wireless, wired, or hybrid) mode of communication (i.e., cloud-based/3rd party service).

Select a monitoring technology platform

The technology selected should provide tools such as dashboards, alerts, historical data analysis, and the ability to integrate with existing operations to monitor in real-time.

Develop a security plan

All currently deployed monitoring systems will need to support secure enrollment, secure authentication, and/or encryption for all connected devices.

The evolution of Smart Hydraulic Cylinders with integrated sensors is revolutionizing how hydraulic systems are monitored, maintained, and optimised. By integrating traditional mechanical power with modern sensing and connectivity, these smart actuators provide transparency, intelligence, and resilience to systems that power the back-end of the industrial and infrastructure systems.

The benefits include predictive maintenance, improved safety, and digital optimisations—all of which will be enhanced as sensor, connectivity, and analytics continue to evolve; hence, the future of hydraulics will be an ever-growing network of smart and connected devices.

Anyone who operates hydraulic systems or is responsible for operational efficiencies should take notice now—Smart Hydraulic Cylinders represent not just a minor improvement over conventional cylinders, but rather they will be the future of motion control in the form of more reliable, efficient, and intelligent systems.