Easy-Riding Compact Electric Shopping Vehicle

We are developing a small compact electric vehicle for shopping purposes. In this study, we fabricated an experimental vehicle, that uses only six small rechargeable AA batteries (7.2 V, approximately 2 A·h) as an electric power source. The vehicle user can select between two driving positions: standing and sitting. A compact transmission with a 90-W DC motor and a speed controller that uses pulse width modulation control was designed as an actuating system. Running experiments were conducted to observe the performance of the fabricated vehicle on a flat floor in a gymnasium. The fabricated vehicle was able to operate for 52 min at a speed of 2.73 km/h. The getting-on and getting-off processes in the vehicle were repeated many times during shopping. The human leg strain while getting on and off the vehicle was investigated by electromyogram measurement. During the getting-on and getting-off processes in the vehicle, the myoelectric potential of the quadriceps increased in the sitting position but did not increase in the standing position. The experimental results show that a user suffers more strain in the sitting position than in the standing position.

Electric Drive for an Agricultural Vehicle

The authors showed the relevance of creating agricultural machines using an electric drive. (Research purpose) The research objective is to develop an experimental prototype vehicle using an electrical schematic diagram of charge and electric drive control. (Materials and methods) The VAZ 111 Oka car was chosen as an experimental vehicle model with an electric drive, since it has a light weight of 645 kilograms, a simple design and a low cost. Mechanical characteristics of the electric motor were calculated and a frequency converter was chosen to control the electric drive. Laboratory bench tests were conducted. (Results and discussion)The authors installed storage batteries to power the electric drive, developed an electrical circuit schematics getting charged from a 220 volt alternating voltage network, and received graphs for the discharge of a 40-storage-battery power supply. (Conclusions) An electrical schematic diagram of charge and electric drive control was developed and implemented on an experimental vehicle model. It was determined that at the electric motor continuous operation with the load current of 1 ampere, the batteries get discharged within 104 minutes; with the current load of 2 amperes, they get discharged within 83 minutes; with 3 amperes – within 65 minutes, and with 5 amperes – within 50 minutes, which is enough to drive around the farm. The authors graphically depicted the dependence of the available capacity level on the voltage, as well as the batteries’ discharge on the time at various load currents. The authors carried out two experimental studies on storage batteries’ charging from alternating voltage with the current of 2 and 3 amperes: in the first case, the charging time was 350 minutes, in the second – 310 minutes. It was found out that when using the developed scheme, the batteries are charged evenly.

Validation and Optimization of Suspension Design for Testing Platform Vehicle

With the application and popularization of the advanced driving assistance system (ADAS), the reliability and stability of ADAS have become its research focus. This article presents a car testing framework for ADAS reliability and stability. Its special suspension has been designed, verified, and optimized in real vehicles according to its working conditions. First, the structure and working principle of the testing platform vehicle are introduced. Then a simulation model is built in MATLAB/Simulink based on the dynamic equation to verify the working characteristics of the suspension. Experimental vehicle tests are conducted for simulation verification purposes. During the analysis, the root-mean-square (RMS) values of vehicle body displacement and dynamic tire deflection are considered evaluation indices. The nondominated sorting genetic algorithm (NSGA-II) is used to optimize the damping, stiffness, and installation position of the suspension system. The findings demonstrate that the specially designed suspension in this article can fulfill the test criteria. Compared with the optimized suspension performance, both the vehicle body displacement and dynamic tire deflection have decreased roughly by 17 and 40%, respectively, which significantly improves the suspension performance and provides a reference for the future designs of testing platform vehicles.

Novel Two-stage Nonlinear Interconnected Unknown Input Observer Design: Hardware & Experimental Vehicle Validation

This paper concerns both vehicle lateral and longitudinal nonlinear dynamics estimation. Consequently, the interlinked vehicle models dependency and the hurdle coupling features will be overcome here thanks to the NONLINEAR INTERCONNECTED UNKNOWN INPUTS OBSERVER (NI-UIO) framework. This interconnection scheme extends the estimation of the lateral motion to the longitudinal one with the unknown accelerator, brake pedal and driver steering torque inputs, as well as tire-ground pneumatic efforts to reduce conservatism and observability problems. The aspects of immeasurable real-time variation in the forward speed and tire slip velocities in front and rear wheels are taken particularly into account. Consequently, TAKAGI-SUGENO (TS) fuzzy form is undertaken to deal with these nonlinearities in the observer synthesis. The INPUT TO STATE STABILITY (ISS) of the estimation errors is exploited using Lyapunov stability arguments to allow more relaxation and additional robustness guarantee regarding the disturbance term of immeasurable nonlinearities. Therein, sufficient conditions of the ISS property are formulated as an optimization problem in terms of linear matrix inequalities (LMIs). Finally, hardware and experimental validation with robustness test are performed with the well-known SHERPA dynamic interactive driving simulator as well as TWINGO vehicle prototype to highlight performances and applicability of the outlined observer.

Addressed Fiber Bragg Structures in Load-Sensing Wheel Hub Bearings

The work presents an approach to instrument the load-sensing bearings for automotive applications for estimation of the loads acting on the wheels. The system comprises fiber-optic sensors based on addressed fiber Bragg structures (AFBS) with two symmetrical phase shifts. A mathematical model for load–deformation relation is presented, and the AFBS interrogation principle is described. The simulation includes (i) modeling of vehicle dynamics in a split-mu braking test, during which the longitudinal wheel loads are obtained, (ii) the subsequent estimation of bearing outer ring deformation using a beam model with simply supported boundary conditions, (iii) the conversion of strain into central frequency shift of AFBS, and (iv) modeling of the beating signal at the photodetector. The simulation results show that the estimation error of the longitudinal wheel force from the strain data acquired from a single measurement point was 5.44% with a root-mean-square error of 113.64 N. A prototype load-sensing bearing was instrumented with a single AFBS sensor and mounted in a front right wheel hub of an experimental vehicle. The experimental setup demonstrated comparable results with the simulation during the braking test. The proposed system with load-sensing bearings is aimed at estimation of the loads acting on the wheels, which serve as input parameters for active safety systems, such as automatic braking, adaptive cruise control, or fully automated driving, in order to enhance their effectiveness and the safety of the vehicle.

Addressed Fiber Bragg Structures in Load Sensing Wheel Hub Bearings

The work presents an approach to instrument the load sensing bearings for automotive applications for estimation of the loads acting on the wheels. The system comprises fiber-optic sensors based on addressed fiber Bragg structures (AFBS) with two symmetrical phase shifts. A mathematical model for load-deformation relation is presented, and the AFBS interrogation principle is described. The simulation includes (i) modeling of vehicle dynamics in a split-mu braking test, during which the longitudinal wheel loads are obtained, (ii) the subsequent estimation of bearing outer ring deformation using a beam model with simply supported boundary conditions, (iii) the conversion of strain into central wavelength shift of AFBS, and (iv) modeling of the beating signal at the photodetector. The simulation results show that the estimation error of the longitudinal wheel force from the strain data acquired from a single measurement point was 5.44% with root-mean-square error of 113.64 N. A prototype load sensing bearing was instrumented with a single AFBS sensor and mounted in a front right wheel hub of an experimental vehicle. The experimental setup demonstrated comparable results with the simulation during the braking test. The proposed system with load-sensing bearings is aimed at estimation of the loads acting on the wheels, which serve as input parameters for active safety systems, such as automatic braking, adaptive cruise control, or fully automated driving, in order to enhance their effectiveness and safety of the vehicle.

Research on dynamic behavior of train dynamic model of straddle-type monorail

This article focus on the dynamic behavior of straddle-type monorail composed of multiple vehicles. The four-vehicle dynamic model of straddle-type monorail considering the coupler force is established on the basis of the coupler dynamic model. The correctness of the model is verified by the real experimental vehicle test of Chongqing straddle monorail line 3 from Huixing station to Changfuroad station. The stable wheel overturning coefficient suitable for monorail is proposed which is used to evaluate the anti-overturning performance of straddle monorail. The vibration response, riding comfort, and dynamic curving behavior are analyzed using the dynamic model. The results show that the vibration response of car body accelerations obtained by single-car model is much different from that obtained by train model. The riding comfort of straddle-type calculated by the single-car model would make large mistake, and a multiple train model is needed. The dynamic curving behavior of straddle-type monorail obtained by the single-car model could represent the dynamic curving behavior well.

Development and Application of Advanced Technological Solutions within Construction of Experimental Vehicle

Changing market requirements, pressure to minimize production costs, competition, but also legislative restrictions have an impact on a number of areas, not excluding the automotive industry. Currently, development trends are moving towards the application of advanced technological solutions and materials, with the aim to reduce vehicle‘s weight, increase their strength and safety, and at the same time reduce the emission of vehicles. The Shell Eco Marathon competition is an excellent platform for the implementation of these activities. The main goal of the competition is to support the creative invention of research teams and bring innovative ideas and technical solutions. The scientific article focuses on a detailed analysis of development steps in the construction of experimental vehicles. The results of the research were presented at a competition in London 2019 with successful achievement. This work is a contribution to the design and aerodynamic optimization of the body and at the same time brings new ideas and structural elements to improve the production power unit.