Solar Engineering Of Thermal Processes

Several simplified design procedures for solar energy systems require monthly average meteorological data. Monthly average daily totals of the solar radiation incident on a horizontal surface are available. However, radiation data on tilted surfaces, required by the design procedures, are generally not available. A simple method of estimating the average daily radiation for each calendar month on surfaces facing directly towards the equator has been presented by Liu and Jordan [1]. This method is verified with experimental measurements and extended to allow calculation of monthly average radiation on surfaces of a wide range of orientations.

Calculation of monthly average insolation on tilted surfaces

Race Car Vehicle Dynamics

This review presents various control strategies for application systems utilizing smart magneto-rheological fluid (MRF) and magneto-rheological elastomers (MRE). It is well known that both MRF and MRE are actively studied and applied to many practical systems such as vehicle dampers. The mandatory requirements for successful applications of MRF and MRE include several factors: advanced material properties, optimal mechanisms, suitable modeling, and appropriate control schemes. Among these requirements, the use of an appropriate control scheme is a crucial factor since it is the final action stage of the application systems to achieve the desired output responses. There are numerous different control strategies which have been applied to many different application systems of MRF and MRE, summarized in this review. In the literature review, advantages and disadvantages of each control scheme are discussed so that potential researchers can develop more effective strategies to achieve higher control performance of many application systems utilizing magneto-rheological materials.

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State of the art of control schemes for smart systems featuring magneto-rheological materials

Much research has gone into developing advanced control algorithms for semi-active suspension. Experimental validation of these control algorithms is critical for their practical applications. This paper investigates a state-observer-based Takagi–Sugeno fuzzy controller (SOTSFC) design for a semi-active quarter-car suspension installed with a magnetorheological (MR) damper and provides proof of the effectiveness of the proposed controller. To conduct the test, a quarter-car test rig and control system hardware were used. Then, a new MR damper was designed and built to fit with the test rig. After that, the SOTSFC for the quarter-car test rig was developed. Finally, several tests were conducted on the quarter-car suspension in order to investigate the real effect of the SOTSFC. It was then compared with the use of a skyhook controller to demonstrate its benefits.

Takagi–Sugeno Fuzzy Control for Semi-Active Vehicle Suspension With a Magnetorheological Damper and Experimental Validation

The usefulness of golf carts for transporting patients in hospital facilities is well known. Nursing homes, medical campuses, and any type of related service require the low-speed transport of patients either in a seat, in a wheelchair, or on a stretcher. This type of transport is not limited to hospitals, but also includes other environments where there are people with special requirements. Think for instance of handicapped or elderly people that need a van because they have to go from their homes to any destination; therefore, the use of golf carts becomes relevant and attractive. Moreover, these carts could be automated for path following and deal with bumps, potholes, or sinkholes. In this context, the present research proposes a novel way to deal with this kind of road obstacle when the gentle transport of patients is a key element. In order to pass over these obstacles, a soft upwards displacement of the front and rear sections of the vehicle was achieved with magnetorheological dampers as part of the vehicle’s suspension system. In this way, people who need this gentle transport will not have any discomfort. Moreover, this work is aligned with the spirit of Automated Vehicles 3.0.

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Soft Passing over Traffic-Calming Devices by Controlled Suspension in Low-Speed Robotic Vehicles for Vulnerable People

Vehicle suspensions are the main responsible subsystems for vehicle ride quality. There is an intrinsic trade-off between comfort and road holding features on all types of suspensions. To tackle this shortcoming, semi-active suspensions provide controllable damping, i.e. they can change their dissipative behavior according to the required type of response and achieve acceptable levels of comfort and stability based on performance standards. In literature, multiple controllers are proposed for semi-active dampers; however, they fail to comply with passenger comfort and vehicle stability criteria simultaneously. This paper presents an online supervisor model that can switch over multiple controllers based on the dynamics of the vehicle and specific performance indexes. Multiple road roughness are constructed and the supervisor must switch the controllers in order to accomplish the desired performances. In particular, the proposed switching strategy can select among skyhook and groundhook controllers for a magnetorheological damper. Results show a favorable response of the switching strategy and an improvement in driving maneuverability of 33% when compared to a passive suspension system.

Supervisor-Based Switching Strategy for Semi-Active Suspension Control

Ensuring passenger comfort in automobiles is one of the most relevant and valued performance indicators. Regarding suspensions, which ensure passenger comfort by isolating the cabin from disturbances coming from the road profile, it is important to accurately measure the vertical dynamics of the passenger to improve comfort with an automatic control strategy. The contribution of this research is the generation of a mathematical model of 7 degrees of freedom (7DOF) from the connection of the 4DOF biodynamic model reported by Bai et al. (2017) and a 3DOF seat-chassis-tire model, limited to the vertical dynamics of a one-quarter vehicle (QoV). This proposal allows a more detailed analysis of the effects of disturbances on passengers and improves comfort through a semi-active suspension, e.g., a Skyhook control aimed at improving the passenger’s sense of comfort. Simulation results are presented in the time and frequency domains. The findings motivate the use of this biodynamic model in more advanced studies involving improvements in suspensions and/or the extension of the study to a half or full vehicle.

Vehicle Suspension System with a Biodynamic model and a Passenger Comfort Oriented Controller

This paper documents the methodology of the sizing of the battery pack and the electric motor of an electric vehicle. The methodology uses the dimensions, weights, driving cycle and other requirements. A step-by-step case study focused on an Electric Urban Bus shows the appliance of this methodology and it opens the discussion of the aspects that needs to be addressed for a first selection on commercial equipment. The results show a work-in-progress simulation process for the selection of commercial equipment and discusses the feasibility of using commercial equipment. Finally, the chosen equipment is compared with those used in current versions of electric commercial buses.

A Methodology for the Sizing of a Battery Pack and Electric Motor: A Work-in-progress Result

Driver assistance systems (DAS) seek to provide relevant information for decision-making in favor of passenger safety, the driving experience and the efficient use of resources. The use of advanced DAS or ADAS is becoming increasingly important and is an area of research with great potential. The contribution of this work is the complete design and validation of an ADAS to estimate fuel consumption, according to certain scenarios. An architecture is proposed as well as the hardware and software for the reading of signals, the data transportation through the ADAS system and their correct storage and processing to obtain results that contribute to decision making. The contribution includes the design of a human-machine interface in a smartphone application and the use of a professional simulator (Dynacar) to validate the preliminary performance of the ADAS. This work could be the baseline for more complex ADAS implementations towards a more resource-efficient and safer driving experience.

L. C. Félix-Herrán

Papers

Soft Passing over Traffic-Calming Devices by Controlled Suspension in Low-Speed Robotic Vehicles for Vulnerable People

Supervisor-Based Switching Strategy for Semi-Active Suspension Control

Vehicle Suspension System with a Biodynamic model and a Passenger Comfort Oriented Controller

A Methodology for the Sizing of a Battery Pack and Electric Motor: A Work-in-progress Result

Design of an Advanced Driver Assistance System -Fuel Consumption Estimation