Browse Topic: Electrohydraulics
Komatsu has launched a new excavator, the PC220LCi-12, that features its latest intelligent machine control technology. IMC 3.0 incorporates automation enhancements and a reported “construction-industry first” technology - factory-integrated 3D boundary control - designed to boost operator productivity. The intelligent machine, displayed previously at Bauma 2025 in Munich, Germany, has many of the same features as the new PC220LC-12 excavator, including a cab that is 28% larger, with 30% more legroom and 50% improved visibility compared to the PC210LC-11 model. Other advantages the new machines offer are up to a 20% increase in fuel efficiency thanks to a new electrohydraulic system and 129-kW (173-hp) next-generation engine, and up to a 20% reduction in maintenance costs due to longer replacement intervals for hydraulic oil and oil filters and longer cleaning intervals for the particulate filter.
Custom electrohydraulic solutions can address unique demands not satisfied by standard components. As mobile equipment is pushed to perform in increasingly demanding and challenging environments - ranging from frozen construction sites to harsh marine applications - some OEMs are discovering that customized solutions can provide significant advantages. Standard electronic controls and hydraulic components are carefully engineered to meet the requirements of a broad range of typical applications. For many OEMs, these components provide a dependable and cost-effective foundation, especially in environments and duties that don't push operational boundaries.
The traditional braking system has been unable to meet the redundant safety requirements of the intelligent vehicle for the braking system. At the same time, under the change of electrification and intelligence, the braking system needs to have the functions of braking boost, braking energy recovery, braking redundancy and so on. Therefore, it is necessary to study the redundant braking boost control of the integrated electro-hydraulic braking system. Based on the brake boost failure problem of the integrated electro-hydraulic brake system, this paper proposes a redundant brake boost control strategy based on the Integrated Brake Control system plus the Redundant Brake Unit configuration, which mainly includes fault diagnosis of Integrated Brake Control brake boost failure, recognition of driver braking intention based on pedal force, pressure control strategy of Integrated Brake Control brake boost and pressure control strategy of Redundant Brake Unit brake boost. The designed control strategy of redundant brake boost is tested and verified on the real vehicle platform. The results show that the designed control strategy can effectively judge the brake boost fault of Integrated Brake Control and accurately identify the driver’s braking intention after the Integrated Brake Control is in brake boost failure. After receiving the expected braking pressure of the driver, the braking pressure is built by Redundant Brake Unit, which can accurately respond to the driver’s braking request and improve the redundant safety of the braking system.
Compact off-highway machines should be as maneuverable, versatile and energy-efficient as possible. Key to achieving these goals is the electronification of the working hydraulics. New mini excavators, wheel loaders and track loaders from the Eurocomach brand, which is part of the Italian Sampierana Group, demonstrates the improvements that can be gained by utilizing electrohydraulic pump control and software. Sampierana first launched the electronification of its working hydraulics on its six-ton mini excavators. “Our compact construction machines are used for a wide variety of jobs,” said Giuseppe Fabbri, technical manager at Sampierana. “Loading, excavating or digging should be very accurate or quick and productive to perform, as needed, and also support a wide range of tools - from shovels to hammers or mowers.”
This SAE Aerospace Information Report (AIR) includes all missile and launch vehicle actuation systems, including electrohydraulic, electropneumatic, and electromechanical types. The data for many systems are not complete. As more information becomes available, periodic updates will be issued to complete existing data sheets and to add new ones. An index by type of vehicle and by type of actuation system is included. The actual data sheets in the body of the report are organized in alphabetical order.
The basics of electrohydraulic valves are easy to understand — they are electrically operated valves that control how hydraulic fluid is sent to actuators. However, to apply electrohydraulic valves for efficient and effective hydraulic systems, designers must consider several factors. This article will explore seven key design considerations for applying electrohydraulic valves.
Mobile hydraulics expert details key trends in controls and IoT connectivity to improve machine design and end-user operations. Off-highway equipment manufacturers are increasingly working with suppliers of drivetrain systems and electrohydraulic (EH) system suppliers to advance the digitalization of mobile-machine technology. OEMs are completing their own R&D efforts to determine the best ways to use digitalized EH systems, sensors, controls and mobile edge gateway devices. They also are working with end-user customers to clearly define what “actionable data” really means for off-highway operations. What device data, or correlated datasets from multiple devices, provides the most value for end users? This is at the crux of creating the IoT-ready technologies that can advance machine performance. The development of IoT-ready technology needs to respond to the requirements of key uses in both OEM and end-user communities. Their needs are interrelated and based on exploiting the potential for applying data to improve machine design and end-user operations. They include:
The four-wheel drive electric sport utility vehicle (SUV) requires high dynamic performance, and the front and rear axles are matched with a high-power motor. High-power motors operate under low-speed and low-torque conditions, with low efficiency and large power loss. To reduce the power loss under low-speed and low-load conditions, a hybrid system of front and rear dual motors and dual hydraulic pumps/motors is designed. A simulation model of a four-wheel drive SUV electrohydraulic hybrid system is constructed. Aiming at the optimal energy consumption, a dynamic programming algorithm is adopted to establish the driving control rules of the vehicle. Constrained by the Economic Commission for Europe Regulation No.13 (ECE R13), a braking-force distribution strategy for the front and rear axles is formulated. On the premise of satisfying the braking safety, regenerative braking is preferred, and the braking energy is recovered to the greatest extent possible. The optimal efficiency curve of the motor is identified, and an energy-management strategy based on the optimal efficiency curve of the motor is established. The comprehensive efficiency of the dual motor for driving and braking is defined, and the energy-management strategy with the optimal comprehensive efficiency of the dual motor is established. Under the New European Driving Cycle (NEDC) condition, the equivalent energy consumption per 100 km for the two energy-management strategies is 13.2208 kWh/100 km and 13.1507 kWh/100 km. The latter has a higher overall efficiency and less power loss. Fuzzy-logic control with the accumulator pressure and its variation as the input and the threshold speed as the output is proposed, which improves the energy-management strategy with the optimal comprehensive efficiency of the dual motor. The results show that the equivalent energy consumption per 100 km for the improved strategy is 13.1481 kWh/100 km, and the vehicle energy consumption is reduced. The system design and control strategy are validated.
A library for modelling faults in multi-domain physical systems is introduced. The library is based on the simulation of fault effects on the system’s behavior. The motivation of how and why to model faults systematically as well as a description of the Modelica®-based library structure with a wizard supporting the semi-automatic augmentation process of faults are outlined. The fault types are classified into continuous and discrete with dedicated type definitions. The application of the Fault library is exemplified in the field of aerospace electrohydraulic actuator. The actuator is equipped with hydromechanical, electrical and digital systems for mitigating failures, which should be tested at an early stage of design. To perform the tests, a multi-domain, dynamic system model is created, wherein failures are systematically simulated using a special approach for fault augmentation. In addition, several complementary tests are obtained by a variants simulation and the simulation results of the fault augmented model are analyzed and using supervised machine learning classifier are demonstrated. Different classification algorithms were compared to each other and analyzed. The accuracy of an appropriate machine learning classifier is analyzed in detail to classify several faults from different domains and to localize their impact by changing a control mode. The selection of relevant output values for the fault classification in the electrohydraulic control system is executed based on the extraction of the feature’s importance.
Hysteresis is a common shortcoming in applying fluid power products to industrial and mobile equipment. It is frequently unreported due to a lack of a cost-effective option to address this issue. As the hydraulics industry works to enhance precision and repeatability in machines, a better understanding of hysteresis-or the variance of output flow from the input command-and how it affects fluid power may help.
The modular designing principle is generally recognized in the automotive industry. However, the issue of building a wheel open-link locomotion module (OLLM) as a combination of steering (wheel turning), springing, traction drive and braking systems is not properly developed yet. An automated control system (ACS) is needed to able to unite and coordinate all the vehicle systems intended to manage the wheel. The automated control system intended to manage the steering and wheel springing parameters is a combination of an information and power channels, through which the wheel is electro-hydraulically driven, and the steering, springing and braking systems are controlled. The number of such channels in a wheeled mover of the vehicle or mobile robot is defined by the wheel type (driving, driven, steered or non-steered wheel). The plurality of such channels forms a complex of automated control systems of the wheeled mover. This complex is responsible for: 1) Controlling the steering wheel of the vehicle (through the systems aimed to steer the wheel at curvilinear motion); 2) Regulating the rigidity and damping parameters of axle suspensions (through controlling the pressure in wheel suspensions); and 3) Vertical displacements of the right and left wheels of the axle (through the control systems of the vertical wheel displacements), which is done in response to the signals arriving to the input of the complex from the main or backup control system of the vehicle. Thus, the wheeled mover is based on OLLMs with ACSs. Theoretically, the design of the OLLM with a complex of ACSs is based on the original complex mathematical model that makes it possible to simulate various interaction schemes of all the vehicle systems, including the effects of the contact (tribological) interaction of the wheel with the support surface. Based on the mathematical model, the operation of all the subsystems of the complex of the ACSs of the WM was studied, namely: the all-wheel steering based on various types of the electrohydraulic servo drive, a regulated wheel springing system and an onboard information and control system. Special attention is given to the interaction of these systems as a part of the vehicle's active safety. The braking system is easily built into the ACS of the OLLM. The results of the studies allowed formulating the main principles of building the complex of ACSs of the WM, technical specifications of the main components of the complex as a mechatronic module of the active safety of the vehicle or mobile robot. The paper presents the layouts of all the components of the complex of ACSs of the WM, and of the complex as a whole. The main outcome of the studies is the idea that an automobile should be built as a complex of mechatronic systems based on modules. An ideal automobile is a multifunctional mobile robot.
Camless Variable Valve Actuation (VVA) technologies have been known for improving fuel economy, reducing emissions, and enhancing engine performance. VVA can be divided into electro-magnetic, electro-hydraulic, and electro-pneumatic actuation. A family of camless VVA designs (called LGD-VVA or Gongda-VVA) has been presented in an earlier SAE publication (SAE 2007-01-1295) that consists of a two-spring actuation, a bypass passage, and an electrohydraulic latch-release mechanism. The two-spring pendulum system is used to provide efficient conversion between the moving mass kinetic energy and the spring potential energy for reduced energy consumption and to be more robust to the operational temperature than the conventional electrohydraulic actuation; and the electrohydraulic mechanism is intended for latch-release function, energy compensation and seating velocity control. This paper presents the prototype design of a variable valve-time and two-lift LGD-VVA with bench and engine test results. The designed actuator is able to achieve 3 ms opening and closing response time with satisfactory valve seating velocity and low energy consumption. This is all achieved with a cost-effective design and open-loop control.
This SAE Aerospace Information Report (AIR) describes a mathematical model that can be used to analyze particle count data. Particle counts that fit the model can be graphically displayed, converted from one counting size-frequency range to another, and extrapolated to estimate counts beyond the measured range. Derivation, applications, and calculations are described.
Insights into sustainability: Environmental, economic, and/or societal goals for a successful, and long-lasting, off-highway industry. - Unskew the talent system and build a sustainable future We live in an age dominated by technology. It's so ubiquitous we seldom consider the fact that every bit of it is a product of human ingenuity. Someone, somewhere, sometime was sufficiently intrigued by a challenge that he or she applied their intelligence, talent, and training to create a solution. I am willing to bet the word “technology” immediately conjured up an image of a smart phone, tablet, or laptop in your mind. One of the main reasons why technology has become synonymous with electronics, and particularly computers, is because electronics and computer science have become huge consumer industries that naturally attract both R&D investments and talented people because of the potential for large returns.
Vehicle Development Insights from Industry: Technologies and Trends for Future Growth - A smarter future. The off-highway equipment industry is extremely dynamic, with environmental pressures and wildly fluctuating markets creating daily challenges. Key business decisions are not made lightly or on a whim. Research is conducted, needs are identified, forecasts are projected, and goals are formed. This approach is taken because most of us believe that even more important than what the industry looks like today is what it will look like in the future. Of course, when a global recession suddenly delivers a vicious uppercut that challenges our strategic plans and standard processes, it's easy for any company to get caught up in the present and lose sight of long-term goals. Some may even be hit so hard that they forget to do what's necessary to maintain a position of strength in the market once the economy rebounds.
Toyota Motor Corporation has developed a new drivetrain for their flagship Lexus LFA sports car. Passionate driving experience was pursued at the forefront of development. Superior vehicle performance, handling, and responsiveness that seem to anticipate the driver's intentions are achieved. Special vehicle packaging and component placement are adopted in the LFA in order to realize such performance. The engine, clutch, and front counter gear are positioned at the front of the vehicle, and the transaxle at the rear. The engine and transaxle are connected by a rigid torque tube. The transaxle is an automated manual transmission equipped with an electrohydraulic actuator for controlling both the shift and clutch operations. This actuator enables accurate control of the transmission and extremely quick response to shift paddle operation by the driver. This paper describes a general outline of the drivetrain and each component that has significantly contributed to LFA product appeal.
Smaller pumps, smarter controllers help maintain power levels even as engine power declines. THE DRIVE to conserve fuel and reduce emissions began by focusing primarily on engines, but it quickly rippled out to hydraulics. Tighter environmental regulations will reduce the amount of power that is available, forcing engineers to improve efficiency and squeeze equipment into less space. By cleverly combining electronics and mechanics, hydraulic system and component designers are rolling out products that will make operators think little has changed. Pumps and valves are shrinking to make way for emissions aftertreatment systems, while electronic controls are evolving to use every bit of energy that is available.
Executive Viewpoints-Vehicle Development Insights from Industry: Driving Factors for Future Innovation. While dealing with the unpleasant results of the last year, engineering teams also undoubtedly looked toward the future-most specifically, at new regulations that are in place or on the near horizon. New EU functional safety standards, the advent of Tier 4 in the U.S. and Stage IV in Europe, and the continuing end-user demands of a better operator experience are all compelling events that must be addressed. On top of (or perhaps in spite of) these new regulations, customers demand these machines more quickly than ever, and OEM senior management teams require machines that differentiate themselves in the market. Even through these tough times, Sauer-Danfoss has been working as part of our customers' development teams to take on these big challenges. Despite the downturn, our test lab and research work has continued. We've taken a vehicle-by-vehicle approach to expand our applications and vehicle systems knowledge, tackling these new regulations while maintaining efficiency and total vehicle performance. Our goal is to deliver system solutions and flexible products that greatly reduce the engineering effort required by our customers to meet these challenges. We are doing this by designing products that simplify system integration, validating standard system design solutions in our test labs, and developing standardized control software solutions that allow engineers to improve both systems performance and operator experience.
Collaboration between OEMs and suppliers leads to new advances, and challenges, for electrohydraulic system control. Off-highway OEMs have found that electrohydraulics are particularly suited to platforms where there is a high degree of coordination required between the propulsion and work functions, as well as those where functional complexity or repetition of task is more suited to an automated approach. Now, they are turning to the technology to help them meet emerging emissions regulations in the U.S. and Europe. “A major development has been the rapid and increasing demand for hydraulic-hybrid propulsion systems that are highly reliant on electronic controls and software functionality to allow them to deliver better fuel savings, reduce mechanical wear, and improve emissions in conjunction with the mechanical and fluid power subsystem,” said Clyde Thomas, Senior Manager of Technical Services at Eaton.
Recent attention has been given to the energy and fuel economy benefits of replacing hydraulic power steering with electronically controlled electrohydraulic power steering (EHPS) systems for commercial vehicles. Given this emerging capability, investigation of the impact such systems would have on overall large truck stability is reported in this paper. It is found that varying the assist gain associated with the EHPS through the motor drive allows for improved stability of articulated vehicles. This paper first presents a method based on feedback of the rate of change in the articulation angle in conjunction with gain-scheduling to instantaneously vary the assist torque provided by the EHPS system. Experimental results of the design are evaluated through a hardware-in-the-loop (HIL) configuration that confirms the performance benefits of incorporating variable gain steering assist in large trucks.
Properly implemented, an electrohydraulic system can add a great deal of automatic control, advanced performance, advanced diagnostics, and remote monitoring to a mobile application. In terms of an electrohydraulic system, the word system is defined a little differently today than it was in the past. For example, if a pulse-width-modulation joystick was working in conjunction with an electronically controlled valve, each was considered a separate system. Today, however, the electronics, hydraulics, engines, and transmissions-working together-comprise a comprehensive electrohydraulic system. In this context, electronics are integrated with hydraulics for a complete system approach. It is crucial, however, for designers to comprehend that not all electronics are designed to be used on mobile equipment. Therefore, when choosing electronic components, the first thing to determine is whether the components have been designed, tested, and evaluated for use in a mobile environment.
Improving efficiency is new design target. The study of ergonomics has brought marked changes in areas ranging from workplaces to vehicles. Those whose workplace is a vehicle also expect to find cabs that are more comfortable. Manufacturers are responding with interiors that come much closer to those of the cars and pickups that bring operators to worksites. Designers are reducing noise, improving comfort, and offering better sight lines as they attempt to make operators more efficient by reducing fatigue.
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