A series elastic brake pedal for improving driving performance under regenerative braking

Electric and hybrid vehicles are favored to decrease the carbon footprint on the planet. The electric motor in these vehicles serves a dual purpose. The use of electric motor for deceleration, by converting the kinetic energy of the vehicle into electrical energy to be stored in the battery is called regenerative braking. Regenerative braking is commonly employed by electrical vehicles to signi cantly improve energy e ciency and to help to meet emission standards. When the regenerative and friction brakes are simultaneously activated by the driver interacting with the brake pedal, the conventional haptic brake pedal feel is disturbed due to the regenerative braking. In particular, while there exists a physical coupling between the brake pedal and the conventional friction brakes, no such physical coupling exists for the regenerative braking. As a result, no reaction forces are fed back to the brake pedal, resulting in a unilateral power ow between the driver and the vehicle. Consequently, the relationship between the brake pedal force and the vehicle deceleration is strongly in uenced by the regenerative braking. This results in a unfamiliar response of the brake pedal, negatively impacting the driver's performance and posing a safety concern. The reaction forces due to regenerative braking can be fed back to the brake pedal, through actuated pedals that re-establish the bilateral power ow to recover the natural haptic pedal feel. We propose a force-feedback brake pedal with series elastic actuation to preserve the conventional brake pedal feel during regenerative braking. The novelty of the proposed design is due to the deliberate introduction of a compliant element between the actuator and the brake pedal whose de ections are measured to estimate interaction forces and to perform closed-loop force control. Thanks to its series elasticity, the force-feedback brake pedal can utilize robust controllers to achieve high delity force control, possesses favorable output impedance characteristics over the entire frequency spectrum, and can be implemented in a compact package using low-cost components. We introduce pedal feel compensation algorithms to recover the missing regenerative brake forces on the brake pedal. The proposed algorithms are implemented for both two-pedal cooperative braking and one-pedal driving conditions. For those driving conditions, the missing pedal feedback due to the regenerative brake forces are rendered through the active pedal to recover the conventional pedal force mapping. In two-pedal cooperative braking, the regenerative braking is activated by pressing the brake pedal, while in one-pedal driving the activation takes place as soon as the throttle pedal is released. The applicability and e ectiveness of the proposed series elastic brake pedal and haptic pedal feel compensation algorithms in terms of driving safety and performance have been investigated through human subject experiments. The experiments have been conducted using a haptic pedal feel platform that consists of a SEA brake pedal, a torque-controlled dynamometer, and a throttle pedal. The dynamometer renders the pedal forces due to friction braking, while the SEA brake pedal renders the missing pedal forces due to the regenerative braking. The throttle pedal is utilized for the activation of regenerative braking in one-pedal driving. The simulator implements a vehicle pursuit task similar to the CAMP protocol and provides visual feedback to the participant. The e ectiveness of the preservation of the natural brake pedal feel has been studied under two-pedal cooperative braking and one-pedal driving scenarios. The experimental results indicate that pedal feel compensation can signi cantly decrease the number of hard braking instances, improving safety for both two-pedal cooperative braking and one-pedal driving. Volunteers also strongly prefer compensation, while they equally prefer and can e ectively utilize both two-pedal and one-pedal driving conditions. The bene cial e ects of haptic pedal feel compensation on safety is evaluated to be larger for the two-pedal cooperative braking condition, as lack of compensation results in sti ening/softening pedal feel characteristics in this cas

İşletmelerde eğitim etkinliklerinin değerlendirilmesine ilişkin alan araştırması

Bilim ve teknolojideki hızlı gelişmeler, yaşadığımız yüzyılı bilgi yüzyılına çevirmekte ve bu yüzyılın toplumları bilgi toplumuna, işletmeleri bilgi işletmelerine ve çalışanları bilgi çalışanlarına dönüşmektedir. Çağımızda bilgi işletmesi olabilmek için çalışanların eğitilmesi gerekmektedir. Günümüzde işletmeleri, uluslar arası pazarlama, yeni gelişen piyasalar ve küreselleşme oldukça etkilemektedir. İşletmelerin yaşama devam edebilmesi, rekabetçi avantaja kavuşabilmesi ve büyümesi için teknolojik gelişmeleri takip edebilmesi gereklidir. Değişimi yakalayan, verimlilik ve iş kalitesinin arttırılması amacına hizmet eden eğitim etkinliklerinin önemi günümüzde pek çok işletme tarafından kabul edilmektedir. İşletmelerin gelişmelere ve yeniliklere uyum sağlayabilmesi için etkin bir eğitim gereklidir. Eğitimin başarısı ise eğitim etkinlikleri sonuçlarının değerlendirilmesi ile mümkündür. Bu çalışmada eğitim etkinlikleri sonuçlarının değerlendirilmesi için kullanılabilir yöntemler incelenmiş ve etkin bir değerlendirmenin sahip olması gereken unsurlar belirlenmeye çalışılmıştır. İşletmelerde eğitim etkinliklerine gereken önemi verdiği görülürken eğitim etkinliklerinin değerlendirilmesine gereken önemi vermedikleri belirlenmiştir. Değerlendirmeye gereken önemin verilmemesinin en önemli sebepleri, bütçe, zaman ve yöntem yetersizliğidir. ABSTRACT THİS RESEARCH İS ABOUT EVALUATING OF TRAİNİNG ACTIVITY IN THE COMPANİES The big developments in information and technology are made turn this century to information century, community of this century to information community. And also this development is made turn companies to information companies, is transfered employees to information employees. İn this century, employees have to be trained for being an information company. Nowadays, international marketing, new markets and globalizm effect on companies. Companies have to follow technological developments to keep going in the market and to have advantages of competition. İn these days, importance of training activities which, are aim to improve guality of work and productive, are accepted by most companies. Companies need training for fitting with developments. Successful of training can be measured by evaluating of training activity results. With this study different type of methods were compared for evaluating og training activity results and tried to be found out elements which are useful for a successful evaluating. Athough companies gave enough attention to training they didin't give the same attention to evaluating of training activity. Most important reasons of that; time, budget and not usening enough methods

Efficacy of haptic pedal feel compensation on driving with regenerative braking

In this article, we study the efficacy of haptic pedal feel compensation on driving safety and performance during regenerative braking. In particular, we evaluate the effectiveness of the preservation of the natural brake pedal feel under two-pedal cooperative braking and one-pedal driving scenarios, through human subject experiments in a simulated vehicle pursuit task. The experimental results indicate that pedal feel compensation can significantly decrease the hard braking instances, improving safety for both two-pedal cooperative braking and one-pedal driving conditions. Volunteers strongly prefer compensation, while they equally prefer and can effectively utilize two-pedal and one-pedal driving conditions. The beneficial effects of haptic pedal feel compensation on safety is evaluated to be larger for the two-pedal cooperative braking condition, as lack of compensation results in stiffening/softening pedal feel characteristics in this case

Bending impact behaviour of sandwich beams with expanded polystyrene foam core: Analysis

This study addresses the bending impact behaviour of sandwich beams made of a low density core bonded to two metal face sheets under low-velocity impact. The geometrical and material non-linearities were considered in the explicit dynamic analysis. The face sheets and core were made of aluminum and expanded polystyrene foam. The effects of design parameters, such as foam density, foam thickness, plate thickness, on the impact energy absorption of the joint were investigated. The foam material was modelled as a crushable foam material, and the cohesive response of the adhesive interface was analysed using the cohesive zone model. Experimental low-speed impact tests were carried out to validate the finite element analysis, and the temporal variations of the contact force and the permanent central deflections at the top and bottom faces of the sandwich beams were in good agreement