Digitisation of a moving assembly operation using multiple depth imaging sensors

Several manufacturing operations continue to be manual even in today’s highly automated industry because the complexity of such operations makes them heavily reliant on human skills, intellect and experience. This work aims to aid the automation of one such operation, the wheel loading operation on the trim and final moving assembly line in automotive production. It proposes a new method that uses multiple low-cost depth imaging sensors, commonly used in gaming, to acquire and digitise key shopfloor data associated with the operation, such as motion characteristics of the vehicle body on the moving conveyor line and the angular positions of alignment features of the parts to be assembled, in order to inform an intelligent automation solution. Experiments are conducted to test the performance of the proposed method across various assembly conditions, and the results are validated against an industry standard method using laser tracking. Some disadvantages of the method are discussed, and suggestions for improvements are suggested. The proposed method has the potential to be adopted to enable the automation of a wide range of moving assembly operations in multiple sectors of the manufacturing industry

Low-cost, high-resolution, fault-robust position and speed estimation for PMSM drives operating in safety-critical systems

In this paper it is shown how to obtain a low-cost, high-resolution and fault-robust position sensing system for permanent magnet synchronous motor drives operating in safety-critical systems, by combining high-frequency signal injection with binary Hall-effect sensors. It is shown that the position error signal obtained via high-frequency signal injection can be merged easily into the quantization-harmonic-decoupling vector tracking observer used to process the Hall-effect sensor signals. The resulting algorithm provides accurate, high-resolution estimates of speed and position throughout the entire speed range; compared to state-of-the-art drives using Hall-effect sensors alone, the low speed performance is greatly improved in healthy conditions and also following position sensor faults. It is envisaged that such a sensing system can be successfully used in applications requiring IEC 61508 SIL 3 or ISO 26262 ASIL D compliance, due to its extremely high mean time to failure and to the very fast recovery of the drive following Hall-effect sensor faults at low speeds. Extensive simulation and experimental results are provided on a 3.7 kW permanent magnet drive

Development and application of optical fibre strain and pressure sensors for in-flight measurements

Fibre optic based sensors are becoming increasingly viable as replacements for traditional flight test sensors. Here we present laboratory, wind tunnel and flight test results of fibre Bragg gratings (FBG) used to measure surface strain and an extrinsic fibre Fabry–Perot interferometric (EFFPI) sensor used to measure unsteady pressure. The calibrated full scale resolution and bandwidth of the FBG and EFFPI sensors were shown to be 0.29% at 2.5 kHz up to 600 με and 0.15% at up to 10 kHz respectively up to 400 Pa. The wind tunnel tests, completed on a 30% scale model, allowed the EFFPI sensor to be developed before incorporation with the FBG system into a Bulldog aerobatic light aircraft. The aircraft was modified and certified based on Certification Standards 23 (CS-23) and flight tested with steady and dynamic manoeuvres. Aerobatic dynamic manoeuvres were performed in flight including a spin over a g-range −1g to +4g and demonstrated both the FBG and the EFFPI instruments to have sufficient resolution to analyse the wing strain and fuselage unsteady pressure characteristics. The steady manoeuvres from the EFFPI sensor matched the wind tunnel data to within experimental error while comparisons of the flight test and wind tunnel EFFPI results with a Kulite pressure sensor showed significant discrepancies between the two sets of data, greater than experimental error. This issue is discussed further in the paper

Dual-task and electrophysiological markers of executive cognitive processing in older adult gait and fall-risk

The role of cognition is becoming increasingly central to our understanding of the complexity of walking gait. In particular, higher-level executive functions are suggested to play a key role in gait and fall-risk, but the specific underlying neurocognitive processes remain unclear. Here, we report two experiments which investigated the cognitive and neural processes underlying older adult gait and falls. Experiment 1 employed a dual-task (DT) paradigm in young and older adults, to assess the relative effects of higher-level executive function tasks (n-Back, Serial Subtraction and visuo-spatial Clock task) in comparison to non-executive distracter tasks (motor response task and alphabet recitation) on gait. All DTs elicited changes in gait for both young and older adults, relative to baseline walking. Significantly greater DT costs were observed for the executive tasks in the older adult group. Experiment 2 compared normal walking gait, seated cognitive performances and concurrent event-related brain potentials (ERPs) in healthy young and older adults, to older adult fallers. No significant differences in cognitive performances were found between fallers and non-fallers. However, an initial late-positivity, considered a potential early P3a, was evident on the Stroop task for older non-fallers, which was notably absent in older fallers. We argue that executive control functions play a prominent role in walking and gait, but the use of neurocognitive processes as a predictor of fall-risk needs further investigation

2012 PWST Workshop Summary

No abstract availabl

Falling Head Over Heels: Investigating the higher-level cognitive and electrophysiological processes underlying gait control and falls in older adults and stroke survivors

Falls are a common problem for Ireland’s older adults and stroke survivors, which have severe consequences for the individual and high care costs for the state. Current clinical interventions that focus solely on musculoskeletal function are not evidenced to be consistently effective in the long term, or in those older adults without muscle and bone impairments (Cadore, Rodríguez-Mañas, Sinclair, & Izquierdo, 2013; Teasell, McRae, Foley, & Bhardwaj, 2002). The role of cognition in gait control and falls has become increasingly apparent, with higher-level executive functions exhibiting a clear relationship with falls and cognitive decline with ageing (Morris, Lord, Bunce, Burn, & Rochester, 2016). This research aims to address a gap in the literature by identifying the specific higher-level executive processes that play a role in gait control, and examining if these processes are impaired in older adults and stroke survivors with a high risk of falling. Behavioural and electrophysiological measures were used to examine walking gait in both single- and dual-task conditions, as well as cognitive performances and the associated event-related potentials in healthy young and older adult “fallers” and “non-fallers”, and also in a sample of stroke survivors. The results suggest that executive top-down processes (working memory in particular), play a role in gait control during dual-task walking generally, and that executive processes are relied upon more in older age. This work suggests that there may also be neural markers of “successful” ageing that differentiate fallers from non-fallers, and that there can be substantial recovery of both cognition and gait post-stroke. These findings support the resource capacity and compensatory theories of neurocognitive ageing, and suggest that executive neuropsychological tasks could be developed to offer alternative cognitive/neural fall screening assessments and rehabilitation programmes for stroke patients and the wider older adult population

Falling Head Over Heels: Investigating the higher-level cognitive and electrophysiological processes underlying gait control and falls in older adults and stroke survivors

Falls are a common problem for Ireland’s older adults and stroke survivors, which have severe consequences for the individual and high care costs for the state. Current clinical interventions that focus solely on musculoskeletal function are not evidenced to be consistently effective in the long term, or in those older adults without muscle and bone impairments (Cadore, Rodríguez-Mañas, Sinclair, & Izquierdo, 2013; Teasell, McRae, Foley, & Bhardwaj, 2002). The role of cognition in gait control and falls has become increasingly apparent, with higher-level executive functions exhibiting a clear relationship with falls and cognitive decline with ageing (Morris, Lord, Bunce, Burn, & Rochester, 2016). This research aims to address a gap in the literature by identifying the specific higher-level executive processes that play a role in gait control, and examining if these processes are impaired in older adults and stroke survivors with a high risk of falling. Behavioural and electrophysiological measures were used to examine walking gait in both single- and dual-task conditions, as well as cognitive performances and the associated event-related potentials in healthy young and older adult “fallers” and “non-fallers”, and also in a sample of stroke survivors. The results suggest that executive top-down processes (working memory in particular), play a role in gait control during dual-task walking generally, and that executive processes are relied upon more in older age. This work suggests that there may also be neural markers of “successful” ageing that differentiate fallers from non-fallers, and that there can be substantial recovery of both cognition and gait post-stroke. These findings support the resource capacity and compensatory theories of neurocognitive ageing, and suggest that executive neuropsychological tasks could be developed to offer alternative cognitive/neural fall screening assessments and rehabilitation programmes for stroke patients and the wider older adult population

A dependable anisotropic magnetoresistance sensor system for automotive applications

The increasing usage of electronic systems in automotive applications aims to enhance passenger safety as well as the performance of the cars. In modern vehicles, the mechanical and hydraulic systems traditionally used have been replaced by X-by-wire systems in which the functions are performed by electronic components. However, the components required should be reliable, have a high-performance, low-cost and capable of operating for a long time in a highly dependable manner despite the harsh operating conditions in automotive applications. Dependability represents the reliance that a user justifiably poses on the service offered by a system, being this especially important in safety-critical applications in which a failure can constitute a threat to people or the environment. An Anisotropic Magnetoresistance (AMR) sensor is a type of magnetic sensor often used for angle measurements in cars. This sensor is affected by performance degradation and catastrophic faults that in principle cause the sensor to stop working suddenly. Therefore, the sensor dependability should be improved in order to guarantee that it will satisfy the continuous increasing dependability as well as accuracy requirements demanded by automotive applications. This research proposes an AMR sensor system that includes a fault-tolerant approach to handle catastrophic faults and self-X properties to maintain the performance of the sensor during its lifetime. Additionally, an interface with the IEEE 1687 standard has been considered, so the sensor is able to communicate with other components of the system in which it is integrated