Mathematical Modelling of a Two – Link Planar Manipulator Arm Using The Denavit – Hartenberg Matrices

The Remote Manipulator System (R.M.S) is a typical example of a robotic manipulator. It is a two – link planar system which is made up of the base link (link 0), the upper arm link (link 1) and the end – effector or forearm link (link 2). The two joints are revolute and are respectively located at the shoulder and the elbow. In this work, frames are assigned to all the links; the direct and inverse kinematics modelling of the manipulator arm is also being discussed. The complete homogeneous transformation matrices relating gripper’s (generally known as the end – effector) frame with the base / reference frame have being derived using Denavit – Hartenberg matrix.Keywords: Manipulator Arm, Frame, Link, Joint, End – Effector, Mapping, Kinematics.Journal of the Nigerian Association of Mathematical Physics, Volume 20 (March, 2012), pp 139 – 15

Mathematical Modelling of a Two – Link Planar Manipulator Arm Using The Denavit – Hartenberg Matrices

The Remote Manipulator System (R.M.S) is a typical example of a robotic manipulator. It is a two – link planar system which is made up of the base link (link 0), the upper arm link (link 1) and the end – effector or forearm link (link 2). The two joints are revolute and are respectively located at the shoulder and the elbow. In this work, frames are assigned to all the links; the direct and inverse kinematics modelling of the manipulator arm is also being discussed. The complete homogeneous transformation matrices relating gripper’s (generally known as the end – effector) frame with the base / reference frame have being derived using Denavit – Hartenberg matrix.Keywords: Manipulator Arm, Frame, Link, Joint, End – Effector, Mapping, Kinematics

Quality of Life of Nigerians with Unilateral Lower Limb Amputation

Purpose: The aims of this study were to determine the QoL of Nigerians with lower limb amputation and to investigate the influence of some clinical and socio-demographic variables on it. Method: Forty-seven individuals with lower limb amputation participated in this study. Participants’ age, gender, marital status, occupation, time since amputation, level of amputation, affected limb and use of prosthesis were recorded. Quality of life was then measured using the WHO QOL-BREF. Data were analysed using mean and standard deviation, Mann-Whitney U test and Kruskal-Wallis test at 0.05 alpha levels. Results: Participants’ overall health and QoL scores were 3.6(SD 0.9) and 3.9(SD 0.7) respectively. Male subjects had significantly higher scores than females in the domains of physical health (p = 0.007), social relationships (p = 0.024) and overall health (p = 0.012). Prosthesis-wearing subjects scored significantly higher in the domains of physical health (p = 0.015), psychological health (p = 0.008) and environment (p = 0.011) and overall health (0.033), than those not wearing prosthesis. Level of amputation, leg dominance and pre-amputation occupational category had no significant influence on participants’ QoL. Conclusion: The findings of this study suggest that the QoL of individuals with lower limb amputation in Nigeria is moderate. The only factors which have significant influence on some QoL domains are gender and use of prosthesis.Implications: Individuals with lower limb amputation, particularly females and those not wearing prosthesis, require special attention. Clinicians should identify barriers to the use of prosthesis so as to enhance their quality of life.</p