Adaptive Controller Algorithm for 2-DOF Humanoid Robot Arm

AbstractA computational model of human motor control for a nonlinear 2 degrees-of-freedom (DOF) robot arm to mimic humanlike behavior is developed and presented in this paper. The model is based on a simple mathematical model of a 2-segment compound pendulum which mimics the human upper arm and forearm. Using the Lagrangian and Euler-Lagrange equations, the 2-DOF dynamic equations were successfully derived and solved using Euler's method. Two types of controllers; a feedback Proportional-Derivative (PD) controller and a feedforward controller, were combined into the model. The algorithm exhibited learning of the necessary torque required in performing the desired Position Control via Specific Trajectory (PCST) rehabilitative task via feedback control and using it as the feedforward torque in subsequent trial motions. After 30 trials, the mean absolute error with respect to the desired motion of the upper arm, showed a decrease from 0.09533 to 0.005859, and the forearm motion from 0.3526 to 0.006138. This decrement trend in mean absolute errorwith increase in number of trials is consistent with the adaptive control strategy of the human arm known as the Feedback Error Learning (FEL) strategy

Automatic mental processes, automatic actions and behaviours in game transfer phenomena: an empirical self-report study using online forum data

Previous studies have demonstrated that the playing of videogames can have both intended and unintended effects. The purpose of this study was to investigate the influence of videogames on players’ mental processes and behaviours in day-to-day settings. A total of 1,023 self-reports from 762 gamers collected from online videogame forums were classified, quantified, described and explained. The data include automatic thoughts, sensations and impulses, automatic mental replays of the game in real life, and voluntary/involuntary behaviours with videogame content. Many gamers reported that they had responded – at least sometimes – to real life stimuli as if they were still playing videogames. This included overreactions, avoidances, and involuntary movements of limbs. These experiences lasted relatively short periods of time but in a minority of players were recurrent. The gamers' experiences appeared to be enhanced by virtual embodiment, repetitive manipulation of game controls, and their gaming habits. However, similar phenomena may also occur when doing other non-gaming activities. The implications of these game transfer experiences are discussed

Siam-weeb based gelatin electrospun scaffolds

Siam weed (Chromolaena odorata) is a traditional herb used to soothe burns and scars and potentially improve dressing and tissue-engineered construct healing ability. The use of Siam weed is mainly in the form of extract. The state of liquid extract limits the use of Siam weed compared to the state of gels and membrane. However, the development of the hybrid of Siam weed in gel and membrane form is lacking. In this study, Siam weed was harvested and made into aqua extracts. The biocompatibility of the aqua extract with various concentrations was tested using Cell Proliferation Assay. The aqua extract was then incorporated into the gelatin solution and spun into nanofibers using an electrospinning technique. The cell proliferation study shows maximum cell proliferation at the 25 μg/ml concentration. The scanning electron microscope images of the electrospun scaffolds show fibrous networks’ microstructures without beads. The concentration of the hybrid solution was found to affect the morphology of the nanofibers by having diameters in the range of 160 ± 90 to 250 ± 150 nm. The Siam-weed-based gelatin electrospun scaffolds provide a native-like microenvironment and potentially improve wound healing ability for biomedical application

Influence of electrode geometry on the lightning impulse breakdown voltage of palm oil

This paper presents a study of lightning impulse breakdown voltage of palm oil under needle/plane and needle/sphere electrode configurations. All tests were carried out at gap distance of 25 mm under both positive and negative polarities. Two types of palm oil and mineral oil were used in this study. The results show that the different electrode geometry has significant impact on the lightning impulse breakdown voltage. It was found that needle/plane geometry has lower breakdown voltage than needle/sphere. The voltage polarity also showed some influence on the lightning breakdown voltage for all fluid samples. Comparing both positive and negative polarities, the percentage of difference between all samples is much higher under needle/plane electrode configuration which can be up to 43%. The positive mean lightning breakdown voltage of palm oil is comparable with the mineral oil

Pre-breakdown streamer propagation and breakdown characteristics of refined bleached and deodorized palm oil under lightning impulse voltage

This paper presents the investigation on the breakdown characteristics and pre-breakdown streamer propagation of Palm Oil (PO) impregnated aged pressboard under positive lightning impulse voltages. The experimental work was carried out under a non-uniform field with needle-plane electrodes configuration. The streamer stopping length and breakdown voltage of 2 types of refined, bleached, and deodorized palm oil were examined in the presence of new and aged pressboards. The pressboard was placed in parallel to the needle-plane electrode at a gap distance of 50 mm. The lightning breakdown voltage was applied to the samples based on 1 shot per step rising voltage method under positive polarity as per IEC 60897. The presence of impregnated pressboard in both PO slightly increases the 50% positive lightning breakdown voltages. PO impregnated pressboards have lower 50% positive lightning breakdown voltages than MO. After subjected to ageing, the positive lightning breakdown voltages for PO and MO impregnated pressboards decrease. In the presence of aged pressboard, the streamers in PO generally propagate further than MO at the same voltage level

Development on Orthotics Insole for Flat Feet Focusing on Sport Usage Evaluated by Electromyography

Running is a method of terrestrial locomotion allowing humans to move rapidly on foot, which related to the movement of lower limb. But for flat feet, running or walking for a long period will give them a high-risk associate with a foot pain. In order to reduce the foot pain, an arch orthotics insole is advised to be wore by the flat feet. This paper provides an extensive study on orthotics insole focusing on sport usage for flat feet. For this silicon rubber Orthotics Insole is designed with sufficient arch support, sufficient thickness, metatarsal pad, heel pad, heel cup and ergonomics dimension specification. The objectives of this research are to design and improve the efficiency of orthotics insole for flat feet focusing on sport usage. Both new orthotics insole and existing insole will be evaluated by using electromyography (EMG) that will record the electrical potential which generated by muscle cells. The output of time domain feature and frequency domain feature for both insoles will be analyzed and compared. This Orthotics Sport Insole ideal to be used by flat feet especially during their sport activity specifically running in order to reduce muscle pain to prevent injuries

Synthesised Schiff Bases As A Potential Corrosion Inhibitor Of Aluminium.

The use of inhibitors for the protection against corrosion in acidic media such as nitric acid, sulfuric acid and hydrochloric acid is widely reported. Schiff bases, a group of compounds containing nitrogen atoms were found to be efficient inhibitors for corrosion in acidic media. Some research work revealed that the inhibition efficiency of Schiff bases was found to be greater than their precursor, amines and aldehydes

Investigation on the lightning breakdown voltage of palm oil and coconut oil under non-uniform field

The increasing interests on the Palm Oil (PO) and Coconut Oil (CO) as a potential alternative for dielectric insulating fluid in transformers encourage a number of researches on different aspects of these oils. Among the common areas under study is the lightning breakdown voltage. In this paper, the lightning breakdown voltage of PO and CO is examined. The type of PO used in this study is Refined, Bleached and Deodorized Palm Oil (RBDPO) Olein. The testing was carried out under non-uniform electric field using needle-sphere electrodes configuration. The influence of the testing methods, rising-voltage and up-and-down on the breakdown voltages are investigated for both types of oils. It was found that the lightning breakdown voltage performance for some of the RBDPO is comparable to Mineral Oil (MO)

The effectiveness of the Occupational Safety and Health Master Plan 2015 (OSH-MP 15) in enhancing government leadership and preventive workplace

Background: Occupational Safety and Health Master Plan for Malaysia 2015 was intended to increase awareness, knowledge and commitment to Occupational Safety and Health in all undertaking to reduce the number of injuries, diseases and fatalities. Objectives: The purpose of this study is to determine the effectiveness of Occupational Safety Health Master Plan for Malaysia 2015 (OSH-MP 15) in enhancing government leadership and preventive workplace culture. Methods: This cross sectional study covered all the states in Malaysia, constituting of 309 employers, 350 Occupational Safety Health practitioners and 360 employees as respondents. There were three questionnaires for three different groups which were employers, Occupational Safety Health practitioners and general employees. The respondents were selected through random sampling. Results: For strategy 1, there was a significant difference in mean of effectiveness of OSH-MP15 between sectors for general workers [F (11, 348) =12.06, p=<0.001], OSH practitioners [F (11, 338) =1.19, p=0.033] and employers [F (11, 297) =5.62, p=<0.001]. For strategy 2, a significant difference in mean of effectiveness of OSH-MP15 between sectors was found for general workers [F (11, 348) =4.52, p=<0.001], OSH practitioners [F (11, 338) =2.28, p=0.011], employers [F (11, 297) =5.74, p=<0.001]. Conclusion: There was a significant difference between the effectiveness of fostering, and enhancing government leadership and inculcating preventive workplace culture among respondents. This study acts as the baseline data for the effectiveness of Occupational Safety and Health Master Plan 2015 in enhancing government leadership and preventive workplace culture

A Review of Different Applications of Wireless Sensor Network (WSN) in Monitoring Rehabilitation

Parkinson’s disease is a neurodegenerative brain disorder that affects movement. The lack of dopamine in the brain cells causes patients have lesser ability to regulate movement and emotions as time goes on. There is no cure for this disease. Although drug therapies are successful for some patients, most of the patients usually develop motor complications. In this paper, we presented our work towards the comparison of several wireless sensor network (WSN) systems for monitoring Parkinson’s patients. The designs of each system are explored. The parts being considered to design a wireless sensor network and limitations are discussed. These findings helped us to suggest a possible wireless sensor network system to supervise Parkinson’s diseases patients for a more extended period of time