Mechanical Engineering - Research Publications

Permanent URI for this collection

http://hdl.handle.net/11343/359

Filters

2018 - 2019 2
Reset filters

Settings
Statistics
Citations
Start date: 2010 × End date: 2019 × Author: Mohammadi, Alireza × Author: Choong, Peter ×

Search Results

Now showing 1 - 2 of 2
  • Item
    Thumbnail Image
    Static force dependency of bone conduction transducer as sensory feedback for stump-socket based prosthesis
    Mayer, RM ; Mohammadi, A ; Alici, G ; Choong, P ; Oetomo, D (Australian Robotics and Automation Association, 2018-01-01)
    The dependency of a novel sensory feedback for stump-socket based prosthesis on the static force is presented using a bone conduction transducer as feedback source. The stimulation was induced onto the bony landmarks of the elbow, specifically the Ulna and presented in an interval halving method. The perception threshold in the range of tactile and auditory perception at three different force levels has been tested. The inter subject variability is bigger than the intra subject variation. The small static force variation suggests a similar approach as in bone conduction hearing aids and therefore a static force bigger than 6N should be applied to perceive a constant stimulation. A mechanical design to include such a novel feedback into a stump-socket needs to account for this requirement. The inter subject variability needs to be addressed by incorporate some kind of person to person calibration of the gain.
  • Item
    Thumbnail Image
    Magnetic-based Soft Tactile Sensors with Deformable Continuous Force Transfer Medium for Resolving Contact Locations in Robotic Grasping and Manipulation
    Mohammadi, A ; Xu, Y ; Tan, Y ; Choong, P ; Oetomo, D (MDPI, 2019-11)
    The resolution of contact location is important in many applications in robotics and automation. This is generally done by using an array of contact or tactile receptors, which increases cost and complexity as the required resolution or area is increased. Tactile sensors have also been developed using a continuous deformable medium between the contact and the receptors, which allows few receptors to interpolate the information among them, avoiding the weakness highlighted in the former approach. The latter is generally used to measure contact force intensity or magnitude but rarely used to identify the contact locations. This paper presents a systematic design and characterisation procedure for magnetic-based soft tactile sensors (utilizing the latter approach with the deformable contact medium) with the goal of locating the contact force location. This systematic procedure provides conditions under which design parameters can be selected, supported by a selected machine learning algorithm, to achieve the desired performance of the tactile sensor in identifying the contact location. An illustrative example, which combines a particular sensor configuration (magnetic hall effect sensor as the receptor, a selected continuous medium and a selected sensing resolution) and a specific data-driven algorithm, is used to illustrate the proposed design procedure. The results of the illustrative example design demonstrates the efficacy of the proposed design procedure and the proposed sensing strategy in identifying a contact location. The resulting sensor is also tested on a robotic hand (Allegro Hand, SimLab Co) to demonstrate its application in real-world scenarios.