| 1. |
- Fu, Bin, et al.
(författare)
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Active suspension in railway vehicles: a literature survey
- 2020
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Ingår i: Railway Engineering Science. - : Springer. - 2662-4745 .- 2662-4753. ; , s. 3-35
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Tidskriftsartikel (refereegranskat)abstract
- Since the concept of active suspensions appeared, its large possible benefits has attracted continuous exploration in the field of railway engineering. With new demands of higher speed, better ride comfort and lower maintenance cost for railway vehicles, active suspensions are very promising technologies. Being the starting point of commercial application of active suspensions in rail vehicles, tilting trains have become a great success in some countries. With increased technical maturity of sensors and actuators, active suspension has unprecedented development opportunities. In this work, the basic concepts are summarized with new theories and solutions that have appeared over the last decade. Experimental studies and the implementation status of different active suspension technologies are described as well. Firstly, tilting trains are briefly described. Thereafter, an in-depth study for active secondary and primary suspensions is performed. For both topics, after an introductory section an explanation of possible solutions existing in the literature is given. The implementation status is reported. Active secondary suspensions are categorized into active and semi-active suspensions. Primary suspensions are instead divided between acting on solid-axle wheelsets and independently rotating wheels. Lastly, a brief summary and outlook is presented in terms of benefits, research status and challenges. The potential for active suspensions in railway applications is outlined.
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| 2. |
- Giossi, Rocco Libero, 1991-, et al.
(författare)
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Active Modal Control of an Innovative Two-Axle Vehicle with Composite Frame Running Gear
- 2021
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Ingår i: IAVSD 2021. - Cham : Springer Science and Business Media Deutschland GmbH. ; , s. 8-17
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Konferensbidrag (refereegranskat)abstract
- Within the Shift2Rail projects Pivot2 and NEXTGEAR, an innovative Metro vehicle with single axle running gear and only one suspension step is proposed. A composite material running gear frame is developed to be used both as structural and as suspension element. The design with only one suspension step can significantly degrade the passengers ride comfort. Thus, active modal control is implemented both in lateral and vertical direction to increase the performance of the system. The running gear frame is modelled in Abaqus® as well as the carbody. Structural modes of both elements are implemented in SIMPACK®. A hydraulic actuator model is developed in Simscape®, where two pressure-controlled valves are used to control the pressure inside the chambers of a double acting hydraulic cylinder. A co-simulation environment is then established between SIMPACK® and Simulink®. The vehicle is running with speeds between 10 and 120 km/h. Active modal control makes it possible to maintain ride comfort levels of conventional bogie vehicles with this innovative single axle and single suspension step running gear, promising substantial weight savings of about 400 kg/m. The single axle running gear solution with active comfort control developed here can be an attractive alternative to bogies, providing reduced Life Cycle Costs.
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| 3. |
- Giossi, Rocco Libero, 1991-, et al.
(författare)
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Gain Scaling for Active Wheelset Steering on Innovative Two-Axle Vehicle
- 2020
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Ingår i: Lecture Notes in Mechanical Engineering. - Cham : Springer International Publishing.
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Konferensbidrag (refereegranskat)abstract
- Within the Shift2Rail project Run2Rail, an innovative single axle running gear with only one suspension step is proposed. A composite material frame shall be used both as structural and as suspension element. To improve curving performance active wheelset steering control is introduced. The selected control aims to minimize the longitudinal creepage by controlling the lateral wheelset position on the track. A two-axle vehicle is created in the MBS program SIMPACK and co-simulation is established with Simulink. The control strategy used is a simple PID control. A set of run cases with different curves and speeds is selected to verify the performance. The control gain optimal for high non-compensated lateral acceleration (NLA) tends to produce unstable results for low speeds. Control gain scaling is introduced based on vehicle speed and online estimation of the curvature. The proposed gain scheduling approach maintains the simple control formulation still solving the instability problem. Gain scheduling allows use of optimal control gains for all combinations of curve radii and vehicle speed and thereby taking the full advantage that the active wheelset steering brings to a vehicle with single axle running gears.
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| 4. |
- Giossi, Rocco Libero, 1991-, et al.
(författare)
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Improved curving performance of an innovative two-axle vehicle: a reasonable feedforward active steering approach
- 2020
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Ingår i: Vehicle System Dynamics. - : Informa UK Limited. - 0042-3114 .- 1744-5159.
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Tidskriftsartikel (refereegranskat)abstract
- A mechatronic rail vehicle with reduced tare weight, two axles and only one level of suspension is proposed with the objective of reducing investment and maintenance costs. A wheelset to carbody connection frame in composite material will be used both as structural and as suspension element. Active control is introduced to steer the wheelsets and improve the curving performance. A feedforward control approach for active curve steering based on non-compensated lateral acceleration and curvature is proposed to overcome stability issues of a feedback approach. The feedforward approach is synthesised starting from the best achievable results of selected feedback approaches in terms of wheel energy dissipation and required actuation force. A set of 357 running cases (embracing 7 curves, 17 speeds per curve and 3 conicities) is used to design the controller. The controller is shown to perform well for conicity and track geometry variations and under the presence of track irregularities.
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| 5. |
- Giossi, Rocco Libero, 1991-
(författare)
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Mechatronic aspects of an innovative two-axle railway vehicle
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Within the Shift2Rail research program the goals for a sustainable growth of the railway sector are set. Among these are substantial reduction of Life Cycle Costs, improved reliability and energy efficiency, the reductionof noise emissions, and the achievement of full interoperability of the rolling stock. Therefore, a new generation of running gear is envisioned.An innovative two-axle vehicle that can reduce weight, initial investmentand maintenance cost, and emissions is proposed for a metro line system. The vehicle proposed will have only one suspension step. To further reducethe weight and incorporate the otherwise missing anti-roll bar, a compositematerial connection frame is introduced. The two-axle configuration suffers from poor ride comfort, due to the lack of a second suspension step acting as filter, and from poor steering capability, due to the long distance between wheelsets. Active suspensions are therefore introduced to improve both ride comfort and steering capability.This Ph.D. thesis showcases the key activities undertaken during the developmentof the innovative vehicle, building a simulation framework where the vehicle can be virtually tested. Several modelling environments are used such as: SIMPACK for vehicle dynamics, Abaqus for finite elements modelling, Simscape for hydraulic physics simulations, and Simulink for control logic development. During the Ph.D. time two elements of the mechatronic vehicle have been designed and manufactured, i.e. the carbon fiber connection frame and the steering active suspension. The two components models have been experimentally validated and introduced into the simulation environment. A ride comfort and a wheelset steering control strategy have been designed to overcome the limitations introduced by the two-axle configuration. The proposed solutions aim at being applicable in the whole operational scenario of the innovative vehicle.The present work emphasises the possibility of introducing innovative mechatronic solutions as an alternative to standard bogie solutions aiming at reducing costs and emissions, blurring the boundaries between academic view and possible industrial applications.
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| 6. |
- Giossi, Rocco Libero, 1991-, et al.
(författare)
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Towards the realization of an innovative rail vehicle - active ride comfort control
- 2022
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Ingår i: Control Engineering Practice. - : Elsevier BV. - 0967-0661 .- 1873-6939. ; 129
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Tidskriftsartikel (refereegranskat)abstract
- The Shift2Rail project Pivot2 introduces an innovative metro vehicle with two single axle running gears with only one suspension step to reduce the vehicle's weight. A U-shaped connection frame is designed in Carbon Fibre Reinforced Polymer to further reduce weight and incorporate the anti-roll bar. Due to the poor ride comfort of the vehicle with standard passive dampers, all six dampers are replaced by hydraulic actuators. Modal control is applied and optimized with genetic algorithms. Despite the good improvements obtained, the weighted vertical acceleration remains above the acceptance level. Two modifications of modal control are studied, i.e., modal control with additional sensor, and blended control. Based on the frequency response of the results, it is proposed a low-pass filtered blended controller to neglect frame accelerations high frequency content. This last improves vertical comfort at the expenses of a more complex control system in comparison to modal control.
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| 7. |
- Giossi, Rocco Libero, 1991-, et al.
(författare)
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Wheel wear reduction of a mechatronic two-axle vehicle controlled with feedforward wheelset steering approaches
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The mechatronic vehicle developed within the Shift2Rail projects Run2Rail, Pivot, NEXTGEAR, and Pivot2 is evaluated with respect to wheel wear. The KTH wear model is used to determine the coefficients of Archard’s wear map to reproduce measured worn wheel profiles of the present vehicle running on Metro Madrid line 10. The same wear model is then used to evaluate the performance of the mechatronic vehicle controlled with two variants of a feedforward controller. The first one uses on-board measurements, while the second one is optimized using firefly optimisation algorithms assuming knowledge of the travelled track. The control strategy based on on-board measurements shows improvements above 60% in terms of lost wheel volume due to wear, compared to the standard bogie vehicle. The optimized controller reaches improvements above 70%. Good coherence is found between improvements predicted with the wear number and the ones achieved in terms of lost wheel volume.
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| 8. |
- Kulkarni, Rohan, 1991-, et al.
(författare)
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iVRIDA: intelligent Vehicle Running Instability Detection Algorithm for high-speed rail vehicles using Temporal Convolution Network : – A pilot study
- 2022
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Ingår i: Proceedings of the 7th European Conference of the Prognostics and Health Management Society 2022. - : PHM Society. ; , s. 269-277
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Konferensbidrag (refereegranskat)abstract
- Intelligent fault identification of rail vehicles from onboard measurements is of utmost importance to reduce the operating and maintenance cost of high-speed vehicles. Early identification of vehicle faults responsible for an unsafe situation, such as the instable running of highspeed vehicles, is very important to ensure the safety of operating rail vehicles. However, this task is challenging because of the nonlinear dynamics associated with multiple subsystems of the rail vehicle. The task becomes more challenging with only accelerations recorded in the carbody where, nevertheless, sensor maintenance is significantly lower compared to axlebox accelerometers. This paper proposes a Temporal Convolution Network (TCN)-based intelligent fault detection algorithm to detect rail vehicle faults. In this investigation, the classifiers are trained and tested with the results of numerical simulations of a high-speed vehicle (200 km/h). The TCN based fault classification algorithm identifies the rail vehicle faults with 98.7% accuracy. The proposed method contributes towards digitalization of rail vehicle maintenance through condition-based and predictive maintenance.
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| 9. |
- Persson, Rickard, et al.
(författare)
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Cost reduction with single axle running gears in metro trains
- 2023
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Ingår i: 2022 Conference Proceedings Transport Research Arena, TRA Lisbon 2022. - : Elsevier B.V.. ; , s. 876-883
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Konferensbidrag (refereegranskat)abstract
- Energy and maintenance costs constitute a large part of the recurring cost for railway operation. The vehicle weight impacts both energy consumption and the need for tamping of the track, while curving performance impacts the curving resistance and the wear on wheels and rails. In the project RUN2Rail and further in NextGear, both parts of the EU-funded initiative Shift2Rail, a single axle running gear with composite frame and active wheelset guidance was proposed for metro vehicles. The present study is comparing a reference vehicle from Metro Madrid with the proposed vehicle in terms of energy consumption and maintenance cost for simulated service on Metro Madrid Line 10 with curvature, gradients, stops and speed profiles considered. The calculated yearly saving for each vehicle become about 50 k€/(year*trainset), split on 20% on energy and 40% on each of wheel and track maintenance.
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| 10. |
- Persson, Rickard, et al.
(författare)
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Possible reduction of energy consumption with single axlerunning gears in a metro train
- 2021
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Konferensbidrag (refereegranskat)abstract
- Running gears form a significant part of the weight of a railway vehicle, and if the weight of these could be reduced, this would affect the vehicle’s energy consumption, especially for services with many stops. In the project RUN2Rail, a part of the EU-funded initiative Shift2Rail, a single axle running gear was proposed for metro vehicles. Active suspensions were suggested to overcome deficiencies in terms of ride comfort and wheelset steering, which are well known for such vehicles. The concept has been further developed in the project NextGear, also part of Shift2Rail, where the material of the running gear frame has been changed from steel to composite to further reduce the weightand the wheelset guidance updated to decrease the running resistance in curves. Prototypes of frame and wheelset steering actuator will be built and tested in the laboratory to validate the performance.The present study is comparing a reference vehicle from Metro Madrid with the proposed vehicle in terms of energy consumption for simulated service on Metro Madrid Line 10 with curvature, gradients, stops and speed profiles considered. Only parameters with relation to the weight, curving performance and auxiliary energy consumption for the active system are assumed different for the vehicles. The vehicles are further assumed to use regenerative braking, hence the energy needed to accelerate the vehicle will be regenerated when braking, but there will be transformation losses with relation to the weight. The simulation results show that the very innovative NextGear vehicles will reduce energy consumption by 8% compared to the reference vehicles. The lower weight and the decreased running resistance in curves contribute about as much to the savings.
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