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The wheels of lunar rovers are prone to bouncing during travel in the low gravity and rugged terrain conditions of the lunar surface, and poor matching of wheel alignment parameters can easily lead to tire wear in such conditions. Focusing on the double-wishbone suspension of lunar rovers, this study presents a wheel alignment parameter optimization method for tire wear reduction. First, a tire brush model is established, and it is determined that the toe angle and camber angle are the main factors affecting the tire wear work. And as the camber angle and toe angle increase, the tire wear work becomes greater. Then, a multi-body dynamic model of the double-wishbone independent suspension in a low-gravity environment is established. Taking the minimum tire wear as the optimization objective, the optimal solution set of alignment parameters such as the tire camber angle and toe angle obtained and the optimal hardpoint coordinate positions are determined. The variation range of the toe angle is optimized from [−0.55°, 1.58°] to [−0.37°, 1.32°]. After optimization, the variation in the toe angle is reduced by 20.4%, the change rate of the camber angle becomes smoother, and the comprehensive wear work of the tire is reduced by 17.47%. The research results provide theoretical guidance for the optimization of wheel alignment parameters of the double-wishbone suspension of the lunar rover.

Active tilting vehicles tilt to the inside of the corner when the vehicle is steering. The tilting motion improves the steering and roll stability of the vehicle. The steering mechanism and the tilting mechanism of the vehicle are connected in parallel. The transmission of the steering mechanism is influenced by the movements of the tilting mechanism. In order to solve this problem, a parallel mechanism is proposed in this paper. It consists of a spatial steering mechanism and a tilting mechanism in parallel. A mathematical model of the parallel mechanism with the wheel alignment parameters has been established. The model calculates the decoupling conditions of the parallel mechanism. In this study, a decoupling method for the parallel mechanism is proposed. A prototype of the parallel mechanism was designed according to the proposed method. The prototype was found to reduce the influence of vehicle tilting on the outer and inner wheel steering angles by up to 0.64% and 0.78%, respectively. The steering geometry correction rate of the prototype is between 1.198 and 0.961. The correctness of the model was verified by experimentation on the prototype. The proposed method can effectively decouple the tilting motion and steering motion of the vehicle and make the wheels on both sides satisfy the Ackerman steering condition.

In order to solve the adverse effect on wheel-hubdriven electric vehicle ride comfort caused by the introduction of hub motor, a three-step screening method is proposed to match and optimize the hard point parameters of vehicle suspension. First, a multibody dynamic model of the prototype vehicle suspension was established based on a multibody dynamic method, and the analytical formulas of the electromagnetic force of the motor were given. Based on the specific conditions of the vehicle and the motor, a dynamics analysis of the suspension was carried out to investigate the effect of the fluctuation of the electromagnetic force of the hub motor on the wheel alignment parameters. Second, the calculation model of the suspension dynamics response was established according to the experiment designed by the Latin hypercube sampling method, and a sensitivity analysis of the suspension hard point coordinate was carried out to obtain the sensitive hard point parameters. Finally, the linear weighted synthetic optimization model of the front wheel alignment parameters of the wheel-hubdriven electric vehicle was elaborated using a multi-objective optimization method, and the multi-objective function was converted into a single objective evaluation function to carry out better suspension hard point parameter optimization. The results show that by optimizing the suspension hard point parameter, the wheel alignment parameters can be controlled within a reasonable range. This optimization ensures that the variation rate of the front wheel alignment parameters of the wheel-hubdriven electric vehicle meets the vehicle design requirements, thus eliminating the adverse impact on vehicle ride comfort caused by the introduction of the hub motor. This paper also illustrates that the three-step screening method is an efficient method of parameter matching, which can satisfactorily solve the problem of engineering applications. The three-step screening method can teach assistant engineer how to use this method to conveniently carry out the design of vehicle suspension, simplify the cumbersome design process, save time, and improve work efficiency and design quality.

The mechanical system dynamics software,ADAMS,is used to establish multi-body dynamics system model for a truck front suspension and steering system. Through the simulation test of wheel travel, front wheel alignment parameters changing along with the wheel travel was obtained.

Wheel alignment of a vehicle composed of toe, camber and caster is essential for stable driving. Among them, the toe angle can be easily adjusted in many commercial vehicles when misaligned. However, there have been many difficulties for a driver to directly detect the misalignment of the toe angle. To solve this problem, this paper proposes a novel system that detects misaligned toe angle in real-time by utilizing the lateral tire force and tire aligning moment. The system is largely divided into the lateral tire force model construction, tire aligning moment model construction, and misalignment detection. During the lateral tire force model and the tire aligning moment model construction, linearized recursive least squares are used to identify parameters necessary for the building of the models. Afterwards, during the misalignment detection, the misaligned toe angle is detected in real-time without additional sensors by estimating the slip angle of each wheel reflecting the toe angle effect based on these two models. The proposed system is verified by the vehicle dynamics software CarSim, and the simulation results show that misaligned toe angle can be successfully detected in real-time while driving.

The torsion bar spring suspension has advantages of good damping effect and simple structure, which make this type of suspension widely used. Suspension stiffness and wheel alignment parameters directly affect vehicle comfort and handling performance, while torsion bar spring and rubber bushing are the key devices to influence suspension stiffness and wheel alignment parameters. In order to improve the calculation accuracy, a modified beam modeling method is proposed to establish the torsion bar spring, and the influence of rubber bushing stiffness on the suspension stiffness and wheel alignment parameters is analyzed. The results show that the modified beam modeling method has high accuracy and good agreement with the test data, the average agreement of suspension stiffness is greater than 98%, and the average agreement of wheel alignment parameters is greater than 90%. Rubber bushings increase suspension stiffness and wheel alignment parameters compared to kinematic hinges. The torsional stiffness of lower rubber bushing has the greatest influence on suspension stiffness, the sensitivity is 8%; the radial stiffness of the lower rubber bushing has the most obvious influence on the wheel alignment parameters, the sensitivity of inclination angle is 12%, the sensitivity of camber angle is 7.8%, the sensitivity of toe angle is 7.3%, and the sensitivity of caster angle is 3.2%. The stiffness of the upper rubber bushing has little influence on suspension stiffness and wheel alignment parameters. This type of research can provide theoretical basis and reference for the design, analysis and optimization of the suspension stiffness and wheel alignment parameters.

Tendon disorders present significant challenges in the realm of musculoskeletal diseases, affecting locomotor activity and causing pain. Current treatments often fall short of achieving complete functional recovery of the tendon. It is crucial to explore, in preclinical research, the pathways governing the loss of tissue homeostasis and its regeneration. In this context, this study aimed to establish a correlation between the unbiased locomotor activity pattern of CRL:CD1 (ICR) mice exposed to uni- or bilateral Achilles tendon (AT) experimental injuries and the key histomorphometric parameters that influence tissue microarchitecture recovery. The study involved the phenotyping of spontaneous and voluntary locomotor activity patterns in male mice using digital ventilated cages (DVC ) with access to running wheels either granted or blocked. The mice underwent non-intrusive 24/7 long-term activity monitoring for the entire study period. This period included 7 days of pre-injury habituation followed by 28 days post-injury. The results revealed significant variations in activity levels based on the type of tendon injury and access to running wheels. Notably, mice with bilateral lesions and unrestricted wheel access exhibited significantly higher activity after surgery. Extracellular matrix (ECM) remodeling, including COL1 deposition and organization, blood vessel remodeling, and metaplasia, as well as cytological tendon parameters, such as cell alignment and angle deviation were enhanced in surgical (bilateral lesion) and husbandry (free access to wheels) groups. Interestingly, correlation matrix analysis uncovered a strong relationship between locomotion and microarchitecture recovery (cell alignment and angle deviation) during tendon healing. Overall, this study highlights the potential of using mice activity metrics obtained from a home-cage monitoring system to predict tendon microarchitecture recovery at both cellular and ECM levels. This provides a scalable experimental setup to address the challenging topic of tendon regeneration using innovative and animal welfare-compliant strategies.

Abstract The influence of rail cant on the overall geometry conditions of railway tracks is assessed both theoretically and experimentally in this study. Extensive data obtained from a light railway line are used for experimental investigations. Modelling of rail—wheel contact using the ADAMS/Rail program is undertaken for theoretical investigations. The need to incorporate rail cant into the development of the track geometry indices is identified, and a method of performing this is proposed. Using this approach, a new track index is defined, for which the main geometry parameters, including alignment, profile, track twist, track gauge, and rail cant (rail twist), are considered. For the development of the new track index, these parameters are combined, assigning justified coefficients to each geometry parameter according to its contribution to the overall conditions of the track. The research methodology and the results are discussed. A practical use of the new index is presented to indicate its capability and applicability.

The parameter modeling for the front double-wishbone independent suspension of a vehicle is set up in the development environment of ADAMS, and then, the kinematics simulation analysis for original design parameters are processed. The contribution of design parameters to the sensitivity of the double-wishbone independent suspension is analyzed and the influence of design parameters on the performance of the suspension such as the wheel alignment parameters is investigated. The optimal design for the suspension is carried on by using the experiment design method, which not only realizes the requirement for good wheel alignment parameters, but also improves the sideways displacement of wheel obviously.

Мета. Створення математично'1 модел1 важконавантажено'1 зубчасто'1 передач! İ3 самовстановлювальною приводною шестернею, а також визначення динамшного навантаження на зубчасту передачу внаслщок процесу встановлення шестерш. Методика. Розрахункова схема й ршняння выносного руху самовстановлювально'1 приводно! шестерш складен! за допомогою методы динамши твердого тша. Аналгтичш вирази для визначення часу самовстановлення шестерш, швидкосл при згткненш й коефшденту динамшного навантаження отримаш шляхом штегрування звичайного диференщального ршняння. Для визначен- ня коефщшнта динамiки використанi методи лшшно! теорй' коливань. Результати. Дослоджено сучасний стан питання щодо конструкци', а також математичного моделювання самовстановлювально! шестернi. 1з використанням методiв динамоки твердого тола складено рiвняння водносного руху рухомо! частини шестернi. Показано, що за допомогою висунутих гiпотез рух шестернi можна звести до обертання навколо миттево! осi. Дослоджено вплив геометричних i динамочних параметрiв приводу барабанного млина на динамшш завантаження у водкрито!' зубчасто! передачi. Отриманi залежносто швидкостi встановлення шестернi вод кута перекосу зубчасто! передачi та шерцшних параметрiв шестернi. За допомогою отриманих залежностей обчисленi час i швидкость установления шестернi водкрито!' зубчасто! передачi барабанного млина МШЦ 5,5 х 6,5. Показано, що в реальному дщпазот значень кута перекосу й параметра шестерш час !! встановлення на колька порядков менше часу перезачеплення зубiв. За наявностi змiнно!' складово! кута перекосу шестерня буде постшно здiйснювати в!дносний рух з ударами, i, у залежносто вод поточного значення кута перекосу, динамочне навантаження на зубчасту передачу може бути значним. Показано, що при встановленш ефективносто застосування самовстановлювально! шестерно необходно враховувати можливе збольшення динамочних навантажень. Обчислено коефшдент динамоки та коефшдент навантаження для номшального значення кута перекосу водкрито!' зубчасто! передачо барабанного млина МШЦ 5,5 х 6,5. Наукова новизна. Розроблена математична модель динамоки самовстановлювально! зубчасто! передачо приводу високо навантажених машин. Проведена колькосна оцонка коефшдента внутрошнього динамочного навантаження водкрито! зубчасто! передачо барабанного млина МШЦ 5,5 х 6,5. Практична значимать. Створена методика визначення динамочно! складово! навантаження на зубчасту передачу зо самовстановлювальною приводною шестернею.