Digital technologies allow for precise, highly responsive and efficient hydraulic control.
By Josh Cosford, Contributing Editor
In the era of Industry 4.0, where the integration of digital technologies is transforming the manufacturing landscape, on-board electronic controllers play a pivotal role in enhancing the efficiency and precision of hydraulic systems. These controllers, embedded within hydraulic valves and pumps, are ushering in a new wave of automation and intelligence, contributing significantly to the evolution of smart manufacturing. Many hydraulic advancements in the past few decades are on the electronic control side rather than the fundamental nature of fluid power components.
On-board electronic controllers are sophisticated devices designed to manage and regulate the operation of hydraulic valves and pumps. However, pretty much any hydraulic component, from hose assemblies to cylinders, has benefited from electronic integration. These controllers utilize advanced sensors, actuators, and microprocessors to monitor and control various parameters, such as pressure, flow, and temperature, in real-time. By integrating these controllers directly into hydraulic components, manufacturers can achieve unprecedented precision, responsiveness, and adaptability in their industrial processes.
Electronic valve controls
Valves were among the first hydraulic components to realize the benefit of on-board electronics. Before I continue, let’s be clear: we’re differentiating between electric and electronic. Electric valves use raw ac or dc power to actuate the spool or poppet. However, electronic describes the use of electric components employing diodes, transistors, and integrated circuits. Even further, digital technology upgrades electronics to the level of computer control by processing binary codes.
Electronics are fascinating because of how closely their concepts resemble hydraulics, not only in the twin relationships between pressure and volts, and between flow and amps, but also in the functions and expression of its individual components. Look at the attached example schematic, which, although not entirely familiar to a hydraulic technician, is really just the electronic version of directional valves, check valves, orifices and pressure valves.
Schematic shows a pulse width modulation (PWM) controller.
The schematic breakdown is for another article on another day, but understand that without any traditional computer control, an analog PWM valve driver can power and control a proportional valve using 1950s technology. Early electronics were bulky, which is why a separate electronic valve driver card installed into the electrical cabinet was the standard for the day. Believe it or not, early electronic control hardware used vacuum tube amplifiers, much like the gear today’s audiophiles still covet. It took miniaturization of solid-state transistors and eventual computer chips to shrink the controls enough to fit on a valve, which led to on-board electronics.
On-board electronic controllers enable proportional control of hydraulic valves, allowing for precise fluid flow and pressure adjustments. This level of control is essential in applications where accuracy is paramount, such as in the aerospace and automotive industries. Proportional valves, driven by on-board electronic controllers, precisely control pressure and flow while requiring only a power source and input signal from the PLC.
Traditional hydraulic systems often suffer from lag and overshooting issues. On-board electronic controllers address these challenges by providing dynamic response capabilities, especially with the implementation of poppet or spool position feedback sensors. These controllers can quickly adjust valve settings to changing conditions, ensuring a more immediate and accurate system response. This is particularly advantageous in applications where rapid and precise movements are crucial, such as in motion control and robotics.
Innercept Digital Proportional Control from HydraForce is a compact proportional cartridge valve with an integrated LVDT position sensor and electronic valve driver that delivers high linearity and repeatability.
Proper digital control came when manufacturers added spool position transducers to the electronics, which use a PID (Proportional, Integral, Derivative) feedback and control system to exponentially improve the accuracy and repeatability of the valve. The PID controller uses a mathematical algorithm to regulate the valve based on inputs from the LDT (linear differential transducer) attached to the spool or poppet. In this case, the poppet is the slip-in cartridge valve since traditional poppets are difficult to modulate.
Advanced pump technologies
On-board electronics aren’t just limited to valves, as hydraulic pumps also benefit significantly from on-board electronic controllers. However, the accoutrement of electronic and computer control can aid pumps and their systems in many more ways than what’s used on valves alone.
On-board electronic controllers facilitate variable speed control in hydraulic pumps, optimizing energy consumption and system efficiency. By adjusting the pump speed according to the actual demand of the system, these controllers contribute to substantial energy savings. This is particularly relevant in applications where the load varies, such as in material handling equipment and manufacturing processes.
Bosch Rexroth’s modular CytroForce is based on energy-on-demand drive Sytronix. CytroForce features a manifold and differential or tandem cylinder connected to this energy-efficient unit. The out-of-the-box system consisting of flow-optimized standard modules reportedly sets new benchmarks in terms of power density, energy efficiency and quiet operations. Sytronix servo variable pump has hydraulic intelligence built into the drive that lets users simply send a profile for position, velocity and force to the drive, which converts that information into commands needed by the servomotor to control the cylinder.
The above example requires an asynchronous electric motor (servo) or variable frequency drive with an inverter duty motor so the motors may spin at speed outside a fixed rpm, which is typical of electric motors. The advantages are more than savings to your electricity bill, as the responsiveness is improved when both the variable pump and the motor contribute to the dynamic requirements of the actuators. Clever programming allows previously unheard-of features such as energy recovery, dynamic load holding and electronic flow sharing.
Load sensing is a crucial feature enabled by on-board electronic controllers in hydraulic pumps. The machine controllers continuously monitor the load on the system and adjust the pump output accordingly to suit the pressure and flow demand of the machine. This results in more efficient energy use, as the pump only delivers the required flow and pressure, reducing unnecessary power consumption. Load sensing is particularly beneficial in mobile hydraulic applications, such as construction equipment and agricultural machinery, and this method goes beyond the traditional hydraulic method. Instead of an arbitrary preset standby pressure applied to every valve and actuator, the digital version provides precisely the pressure and flow as required based on demand.
Danfoss’ Digital Displacement Pump is a digitally controlled pump. The pump controller activates each piston individually, making the pump displacement electronically variable and resulting in fast, accurate flow control. The unique radial pump design provides unmatched full and part load efficiency. The pump boasts easy controllability with the fast response time and multiple independent outlets in a compact package.
The integration of electronic controllers allows for remote monitoring and control of hydraulic pumps. Manufacturers can use Industrial Internet of Things (IIoT) technologies to access real-time data on pump performance, identify potential issues, and make adjustments remotely. This capability enhances overall system reliability and enables a proactive approach to maintenance, reducing operational costs and downtime.
Adopting on-board electronic controllers aligns seamlessly with the principles of Industry 4.0, which emphasizes connectivity, data-driven decision-making, and automation. These controllers serve as the bridge between the physical and digital realms, facilitating hydraulic systems integration into the broader industrial network.
Future opportunities
On-board electronic controllers generate a wealth of data related to the performance of hydraulic valves and pumps. When harnessed and analyzed, these data provide valuable insights into the hydraulic system’s efficiency, reliability, and overall health. Manufacturers can use this information to make informed decisions, optimize processes, and identify opportunities for improvement. With the proliferation of artificial intelligence, we can take this principle further and have the machine make its own optimization and improvement decisions.
On-board electronic controllers enable seamless communication between hydraulic components and other devices within the manufacturing environment. This interconnectivity is vital for achieving a synchronized and coordinated operation of different systems. For example, in a production line, electronic controllers in hydraulic valves and pumps can communicate with controllers in other machinery, ensuring a harmonized workflow. Many traditional controller area networks, such as CANopen and DeviceNet, continue to thrive in today’s market, but others, such as Time-Sensitive Networking (TSN), are gaining ground.
The advanced capabilities of on-board electronic controllers contribute to developing adaptive and autonomous systems. In an Industry 4.0 setting, hydraulic systems can autonomously adjust their parameters based on real-time data, environmental conditions, and production requirements. This level of adaptability enhances overall system performance and responsiveness, contributing to the agility demanded by modern manufacturing.
While on-board electronic controllers offer significant benefits, their integration into hydraulic systems is not without challenges. Implementing on-board electronic controllers involves additional investment costs, including purchasing sensors, actuators, and advanced control systems. Small and medium-sized enterprises (SMEs) may find the initial investment challenging, although the long-term benefits in terms of efficiency and reliability can outweigh the upfront costs.
As hydraulic systems become more interconnected, there is an increased risk of cybersecurity threats. Manufacturers must prioritize implementing robust cybersecurity measures to protect sensitive data and ensure the secure operation of electronic controllers. This includes regular updates, encryption, and adherence to industry-specific cybersecurity standards. The post-pandemic world has seen an exponential rise in cybersecurity threats, so risk aversion may keep many enterprises within the Industry 3.0 realm until the security solutions are more robust.
Besides the financial cost and security threats, we must also consider the challenges we face in growing and maintaining the technical personnel within fluid power. Integrating on-board electronic controllers necessitates a workforce with expertise in hydraulic systems and digital technologies. Training programs and educational initiatives are essential to equip professionals with the skills required to design, implement, and maintain these advanced systems.
On-board electronic controllers are at the forefront of the technological revolution shaping Industry 4.0. Their integration into hydraulic valves and pumps is transforming conventional hydraulic systems into intelligent, adaptive, and efficient components of modern manufacturing processes. The enhanced precision, dynamic response, and connectivity these controllers provide contribute to improved energy efficiency, reduced downtime, and overall optimization of industrial operations.
As the manufacturing landscape continues to evolve, the role of on-board electronic controllers will become increasingly prominent. Manufacturers must embrace these advancements, recognizing the long-term benefits they offer in terms of sustainability, competitiveness, and resilience in the ever-changing global market. The journey toward smart manufacturing fueled by on-board electronic controllers is a testament to the transformative power of technology in shaping the future of industry.
Filed Under: Components Oil Coolers, Pumps & Motors, Trending, Valves & Valve Manifolds
