Active Seat Research Articles

Controller of Pneumatic Muscles Implemented in Active Seat Suspension

In this work, we present a study on seat suspension technology that integrates pneumatic muscles, marking a significant advancement in active vibration control. This innovative approach addresses the limitations of traditional suspension systems, providing enhanced comfort and adaptability. A key achievement is the development of a mathematical model for controlling horizontal seat vibration, which serves as a valuable design tool for evaluating seat suspension under various conditions and control strategies. The creation of a custom microcontroller, benchmarked against a standard from National Instruments, highlights the practical applications of this research. Positive results suggest a promising future for this technology in industrial settings, where vibration reduction is critical. The system’s scalability and user-adjustable signal levels further enhance its potential for widespread industrial adoption.

Improving Ride Comfort approach by Fuzzy and Genetic Base PID Controller in Active Seat Suspension

Improving Ride Comfort approach by Fuzzy and Genetic Base PID Controller in Active Seat Suspension

Improving ride comfort approach by fuzzy and genetic-based PID controller in active seat suspension

Improving ride comfort approach by fuzzy and genetic-based PID controller in active seat suspension

Multi-Degree-of-Freedom Active Seat Suspension for Ultra-Compact Mobility

Multi-Degree-of-Freedom Active Seat Suspension for Ultra-Compact Mobility

Study of AEB and active seat belt on driver injury in vehicle–vehicle frontal oblique crash

The safety of vehicle occupants in oblique collision scenarios continues to pose challenges, even with the implementation of Automatic Emergency Braking (AEB) systems. While AEB reduces collision risks, studies indicate it may heighten injury risks for out-of-position (OOP) occupants. To counteract this issue, the integration of active seat belts in vehicles equipped with AEB systems is recommended. Firstly, this study established an oblique angle collision scenario post-AEB activation using data from the Chinese National Automobile Accident In-depth Investigation System (NAIS) database, analyzed through Prescan software. The dynamic response of the vehicle was examined. Following this, finite element (FE) models were validated to assess the effects of collision overlap rate, AEB braking strategy, and active seat belt pre-tensioning on occupant injuries and kinematics. Under specific collision conditions, the impact of the timing and amount of seat belt pre-tensioning, as well as airbag deployment timing on occupant injuries, was also explored. Findings revealed that a 75% collision overlap rate significantly increases driver injury risk. Active seat belts effectively mitigate injuries caused by OOP statuses during AEB interventions, with the lowest Weighted Injury Criterion (WIC) observed at a pre-tensioning time of 200 ms for active seat belts. The study further suggests that optimal results in reducing occupant injuries are achieved when active pre-tensioning seat belts are complemented by appropriately timed airbag deployment.

Development of Learning Facilities for ADHD Student Aged 6-9 Years Old at Special School in Indonesia

Attention-Deficit / Hyperactivity Disorder (ADHD) is a neurobiological disorder in the form of inability to focus attention, easily distracted, impulsive, and hyperactive. Children with ADHD are usually aggressive, unable calm down, are difficult to teach, and have trouble focusing when doing an activity. With this, children with ADHD need treatment, special handling, as well as facilities and infrastructure that are suitable for children with ADHD. One special facility for ADHD that looks significant compared to other normal facilities is a study furniture designed for children with ADHD. The study furniture is important because it often interacts with children with ADHD for a long time. The good consideration of a design is the fulfillment of needs that can adapt to user conditions. To get a solution, interviews with experts were conducted, potential users that is children with ADHD aged 6-9 years, literature studies on ADHD, active seating, fidgeting, ergonomics, color, benchmarking to product existing, and analysis of user needs. The results of this design are furniture sets in the form of tables and chairs that use active seating, calm, adjustable, and safe as the concept to support the learning activities of children with ADHD in special schools. The chair design uses the concept of active seating in the form of whole body fidgeting to support hyperactive and inattention symtoms. This design utilizes digital simulation to digitize the concept and simulate it, reducing trial and error during prototype development. Furniture with adjustable height system for children aged 6-9 years with a simple and safe form for the needs of children with ADHD. This design uses muted brown color to give a clean impression and not cause distraction, combined with a muted blue color to give a calming feel from a psychological standpoint and fulfill user preferences.

Development of a Digital Twin for a Hydraulic, Active Seat Suspension System

The vibrations induced by the soil irregularities and other equivalent disturbances on agricultural tractors represent a major cause of disease for tractor drivers. The reduction of vibration exposure of operators is a topic of interest for the (Italian) National Institute for Insurance against Accidents at Work (INAIL). Several passive, semi-active, and active solutions are commercially available for the seat or the cabin suspension to isolate the driver from the vibrations. A prototype of a hydraulic active suspension system for the operator seat has been developed in the laboratories of INAIL. In this paper, nonlinear multi-physics modeling of the prototype has been carried after an experimental identification of the actuation system and specifically of the control valve parameters. The model is adjusted to retrace the system’s response and is used as a digital twin of the physical prototype to develop and optimize the control system. An equivalent simplified model is obtained to design a proper control strategy for the active suspension system. Finally, the controller is tested on the digital twin of the system to assess its performance in isolating vibrations.

Driver Injury from Vehicle Side Impacts When Automatic Emergency Braking and Active Seat Belts Are Used.

As an advanced driver assistance system, automatic emergency braking (AEB) can effectively reduce accidents by using high-precision and high-coverage sensors. In particular, it has a significant advantage in reducing front-end collisions and rear-end accidents. Unfortunately, avoiding side collisions is a challenging problem for AEB. To tackle these challenges, we propose active seat belt pretensioning on driver injury in vehicles equipped with AEB in unavoidable side crashes. Firstly, records of impact cases from China's National Automobile Accident In-Depth Investigation System were used to investigate a scenario in which a vehicle is impacted by an oncoming car after the vehicle's AEB system is triggered. The scenario was created using PreScan software. Then, the simulated vehicles in the side impact were devised using a finite element model of the Toyota Yaris and a moving barrier. These were constructed in HyperMesh software along with models of the driver's side seatbelt, side airbag, and side curtain airbag. Moreover, the models were verified, and driver out-of-position instances and injuries were evaluated in simulations with different AEB intensities up to 0.7 g for three typical side impact angles. Last but not least, the optimal combination of seatbelt pretensioning and the timing thereof for minimizing driver injury at each side impact angle was identified using orthogonal tests; immediate (at 0 ms) pretensioning at 80 N was applied. Our experiments show that our active seatbelt with the above parameters reduced the weighted injury criterion by 5.94%, 22.05%, and 20.37% at impact angles of 90°, 105°, and 120°, respectively, compared to that of a conventional seatbelt. The results of the experiment can be used as a reference to appropriately set the collision parameters of active seat belts for vehicles with AEB.

FORMATION OF THE EDUCATIONAL SPACE OF THE NEW UKRAINIAN SCHOOL: ANALYSIS OF EXISTING REQUIREMENTS AND RECOMMENDATIONS

The article deals with the analysis of the requirements and recommendations for the creation of the educational space of the New Ukrainian School. It is emphasized that the educational space includes not only educational programs, methods, tools, but everything that surrounds students and ensures the creation of effective conditions for the development of their key competencies. It is accented that at the state level the creation of a modern effective new educational space is regulated by the legal framework, in particular, the Laws of Ukraine, Orders of the Ministry of Education and Science of Ukraine, State standards, norms and rules.There were pointed out such components of the new educational space as: creative external and internal design; comfort and energy efficiency; modern conditions for learning, development and communication; barrier-free space and conditions for inclusive education; multifunctional environment. It is emphasized that the organization of the educational space of the classroom requires the use of new IT technologies, multimedia tools, the creation of cells, which makes it possible to create various opportunities for various types of activities, cause joy, stimulate imagination, and motivate learning. Great attention is paid to external (3D and thematic design with maximum use of the facade, modern murals) and internal (learning rooms and common areas) design. The focus is on equipping with modern furniture that ensures a healthy body position due to constant change of working posture (the so-called «active seat principle»).It is noted that the creation of a new effective educational space requires changes in the planning of buildings of educational institutions and school grounds. It is emphasized that most of modern school buildings are not suitable for the implementation of the latest pedagogical approaches and don’t make it possible to diversify the organization of the educational process. Renovation of a school building can be carried out by means of cosmetic or major repairs or total reconstruction with additions and superstructures.

A multi-objective optimization method based on NSGA-II algorithm and entropy weighted TOPSIS for fuzzy active seat suspension of articulated truck semi-trailer

This paper aims to optimize a fuzzy logic controller (FLC) active seat suspension applied to an articulated truck semi-trailer seat to improve ride comfort considering the energy consumption of the controller. The proposed truck model is a linear truck with 13 degree-of-freedom (DOF). Two objective functions are defined seat root mean square (RMS) acceleration related to ride comfort and controller RMS force pertaining to the energy consumption of the controller. The Pareto Front is obtained for these two objective functions using the multi-objective optimization method in MATLAB. The optimization is based on the Non-Dominated Sorting Genetic Algorithm (NSGA-II), which has been proposed as a powerful decision space exploration engine based on a genetic algorithm (GA) for solving a multi-objective function problem. Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), which is simple and effective, selects a set of optimal controller parameters. In addition, considering the changes of effective parameters in the truck, including trailer load and location, tyres’ stiffness and the driver’s mass, has been investigated to provide Monte Carlo sensitivity analysis of these parameters on objective functions. Finally, using ISO 2631-1, the ride comfort and controller required force levels before and after optimization are compared. The results of this optimization indicate a significant improvement in ride comfort and controller force which has been different in various conditions of truck speed and road classes. The results have shown that the maximum amount of improvement in ride comfort is about 25% which happens on Class-C road (at the truck speed of 60 km/h), and the control force reduction peaks at around 60%, which occurs on Class-A road (at the truck speed of 60 km/h). The simulation is validated by MSC-ADAMS software.

Adaptive fuzzy fault-tolerant control for active seat suspension systems with full-state constraints

In this paper, an adaptive fuzzy fault-tolerant control (FTC) scheme is proposed for active seat suspension systems. The addressed system contains electromagnetic actuator faults. In addition, the constraints of the displacements of the car seat, active suspension, and wheel, their vertical vibration speeds and current intensity are included. In the control design, since the systems have dynamic characteristics of complexities and spring non-linearities, the fuzzy logic systems are utilized to approximate the unknown nonlinear dynamics. By the aid of Barrier Lyapunov functions and based on the adaptive backstepping recursive design algorithm, a novel adaptive fuzzy FTC scheme is formulated. When the electromagnetic actuator fails, the developed control scheme can guarantee that all the vertical vibration states are stable. Eventually, the effectiveness of the presented control method is offered to illustrate by a random road surface.

Active Seat Suspension for Ultra-compact Mobility with Small Motor

Active Seat Suspension for Ultra-compact Mobility with Small Motor

Modelling and simulation of the energy regenerative system for active horizontal seat suspension driven by an induction motor

The paper investigates the design and performance of an active horizontal seat suspension driven by an induction motor, with the aim of reducing harmful vibrations and enhancing energy efficiency. The physical model employs a permanent magnet synchronous motor (PMSM) as a modern actuator to generate the active force. Both passive and active seat suspensions are examined, revealing that the active system significantly reduces resonant vibration by applying electromagnetic torque from an induction motor. The motoring/braking principle is explored, where braking an induction motor returns electric energy to the servo drive system, and regenerative braking is utilized to charge batteries. However, the current regenerative braking system recovers only 3% of power. A novel control design methodology is proposed for the subsequent project to enhance suspension dynamics, attenuate vibrations transmitted to the human body, and minimize energy consumption during operation. The proposed energy-regenerative electromagnetic actuator model, in conjunction with advanced programmable micro-controller algorithms and inverter switching schemes, aims to optimize energy recuperation and vibration energy harvesting in the vibration reduction system.

Modeling, Simulation and Optimization of Agricultural Tillage Process Vibrations using an Interactive Active Control System

Tractor operators have to work for long hours to perform different tasks. During tillage, implements are attached to the tractor for soil preparations for crop production. The attached implements also have direct effect on vibrations of tractors. Drivers of tractors are exposed to different frequency vibrations which effect their health badly. In this study, the vibrations transmitted during tillage to seat of operator were measured using accelerometer and root mean square (RMS) accelerations was analysed according to ISO standard. Tests were carried out with different type of implements (Cultivator and Disc Harrow) and at different forward speeds of tractor. The dynamic model of tractor and tillage implements was created in MATLAB-Simulink software. An active seat suspension was designed with PID and Fuzzy Logic Controllers and was analysed for improvement in ride comfort level of driver. The results reveal that designed controllers reduce the RMS accelerations at operator’s seat base by 69% as compared to passive seat.

Research on Tractor Active Seat Suspension Based on Model Predictive Control

Research on Tractor Active Seat Suspension Based on Model Predictive Control

Vibration Characteristics Control of Resonance Point in Vehicle: Fundamental Considerations of Control System without Displacement and Velocity Information

The deterioration of ride comfort in ultra-compact vehicles has recently become an increasing concern. Active seat suspension was proposed to improve the ride comfort of ultra-compact vehicles. An active seat suspension is a vibration control device that is easily installed. The general vibration control system of the active seat suspension is fed back to the displacement and velocity by integrating the measured seat acceleration. This control has problems, such as control delay and deviation by integration. In this study, we focused on vibration control using acceleration directly. First, we established a control model that feeds back the acceleration to terminate the error occurring in the integral process and investigated the change in vibration characteristics in the case where the feedback gain of acceleration was changed. Second, the control system was analyzed to investigate the performance of the control based on the frequency characteristics. As a result, it was confirmed that the frequency response changes when the feedback gain is changed. In acceleration feedback control, ride comfort was improved by selecting a proper feedback gain because the characteristics of frequency were changed by the gain.

Using Active Seat Belt Retractions to Mitigate Motion Sickness in Automated Driving

The introduction of automated-driving functions provides passengers with the opportunity to engage in non-driving related tasks during the ride. However, this benefit might be compromised by an increased incidence of motion sickness. Therefore, we investigated the effectiveness of active seat belt retractions as a countermeasure against motion sickness during inattentive automated driving. We hypothesized that seat belt retractions would mitigate motion sickness by supporting passengers to anticipate upcoming braking maneuvers, by actively tensioning their neck muscles and, thereby, reducing the extent of forward head movement while braking. In a motion base driving simulator, 26 participants encountered two 30 min automated drives in slow-moving traffic: one drive with active seat belt retractions before each braking maneuver and a baseline drive without. The results revealed that there was no difference in perceived motion sickness between both experimental conditions. Seat belt retractions resulted in an increased activity of the lateral neck muscles and supported drivers to anticipate braking maneuvers. However, at the same time, the retractions led to an increased magnitude of head movement in response to braking. This research lays the groundwork for future research on active seat belt retractions as a countermeasure against motion sickness and provides directions for future work.

Research on Vibration Reduction Performance of Electromagnetic Active Seat Suspension Based on Sliding Mode Control.

Vehicle seats have a significant impact on the comfort of passengers. The development of seats is a field in which scholars are widely concerned. In this study, we add an electromagnetic levitation structure and design a new active seat suspension based on the passive seat suspension. Then, simulation research is carried out based on a C-level road surface combined with integral sliding mode control and state feedback control. The results show that both state feedback control and integral sliding mode control positively affect vehicle seat vibration reduction, and integral sliding mode control has a better anti-interference effect than state feedback control. At the same time, it is proved that the seat suspension has good working characteristics and economy.

Achaemenid ceramics from the site Beniamin II (Shirak, Armenia): the end of the 6th to the mid 4th centuries BC

In Beniamin, not far from Gyumri, Armenia, at the foot of a hill on which an Achaemenid palace was built, several semi-excavated constructions dating back from the 6th-4th centuries BC were found. Hosting metallurgy workshops at the beginning of their existence, they were later the seat of a livestock activity. From artisanal iron workshop to long-house, they offer a double interest: They concern the economy of an Achaemenid palatial domain, and present a typical architecture of the Armenian plateau, very similar to the houses described by Xenophon in the 5th century BC, in the Anabasis, the epic of the Ten Thousand. Finally, six main periods of occupation were highlighted by the analysis of stratigraphic data and archaeological artifacts discovered. Continuing the first article devoted to architecture and its evolution, this contribution aims to present the catalogue of the productions collected in the Achaemenid levels of periods I to V. The evolution of these productions clearly attests the function of the buildings demonstrating essential similarities to that of the contemporary site of Tsaghkahovit. After the rapid disappearance of coarse and often decorated common forms (decorated black pottery – group 1A), the present catalogue of Achaemenid ceramics is mainly characterized by productions with red slip (Type 3), black common wares (Type 1b and C), with special predominance of productions of brown burnished ware (clear or polished – type 4). Painted ceramics are almost absent from the catalogue of productions.

Safety of active pre-collision seat rotation strategies for autonomous vehicles: injury risk evaluation of occupant’s neck

The development of autonomous driving technology has engendered new requirements for the safety of the occupants of autonomous vehicles. Different variants of seat configurations, including face-to-face rides and rotating seats, have been implemented in autonomous vehicles. Furthermore, pre-collision active seat rotation strategies have been proposed for the safety of the occupants of autonomous vehicles. However, further evaluations are required to determine whether the active seat rotation strategy could cause injuries to the occupants during a significantly rapid rotation process. In this study, two types of multi-rigid body seat-occupant models and a finite element model of the occupant’s cervical spine were designed. The validity of the multi-rigid body model for the seat occupant was verified through a frontal collision simulation test. Considering the influence of different seat types and rotation directions on the risk of neck injuries to the occupants, four simulations were conducted based on the condition that the seat rotated by 90° in 200 ms. The kinematic and biomechanical aspects of the risk of injuries to the occupant’s cervical spine during the active seat rotation strategy were assessed, and the essential causes of these injuries were discussed. The results indicate that, in the absence of leg baffles and foot supports, seat rotation toward the diagonal line of the seatbelt poses different degrees of risk of injuries to the cervical spine, platysma, sternocleidomastoid, common carotid artery, external jugular vein, and internal jugular vein. Therefore, the seats of highly or fully autonomous vehicles should be designed to prevent this scenario.