A pattern recognition system is described for recognizing shipbuilding parts using artificial neural networks and Fourier descriptors. The system uses shape contour information that is invariant of size, translation, and rotation. Fourier descriptors provide information, and the neural networks make decisions about the shapes. A brief review of the current state of the art is included, and results from testing show that the system distinguished between various shapes and proved to be a valid approach.

Purpose -The purpose of this paper is to investigate the effect on time to complete a task depending on how a human operator interacts with a mobile-robot. Interaction is investigated using two tele-operated mobile-robot systems, three different ways of interacting with robots and several different environments. The speed of a tele-operator in completing progressively more complicated driving tasks is investigated also. Design/methodology/approach -Tele-operators are timed completing a series of tasks using a joystick to control a mobile-robot. They either watch the robot while operating it, or sit at a computer and view scenes remotely on a screen. Cameras are either mounted on the robot, or so that they view both the environment and robot. Tele-operators complete tests both with and without sensors. One robot system uses an umbilical cable and one uses a radio link. Findings -In simple environments, a tele-operator may perform better without a sensor system to assist them but in more complicated environments then a tele-operator may perform better with a sensor system to assist. Tele-operators may also tend to perform better with a radio link than with an umbilical connection. Tele-operators sometimes perform better with a camera mounted on the robot compared with pre-mounted cameras observing the environment (but that depends on tasks being performed). Research limitations/implications -Tele-operated systems rely heavily on visual feedback and experienced operators. This paper investigates how to make tasks easier. Practical implications -The paper suggests that the amount of sensor support should be varied depending on circumstances. Originality/value -Results show that human tele-operators perform better without the assistance of a sensor systems in simple environments.

Purpose -The purpose of this paper is to develop an electronic solution to effectively lock swivelling wheel steering positions to driver-control. Simple and affordable systems are described to assist forklift users in steering their walkie type forklifts or pallet jacks across sloping ground. Design/methodology/approach -A rolling road was created as an assessment tool and trials with both the test bed and in real situations were conducted to evaluate the new systems. The small swivel detector that was created could be successfully attached to swivelling wheel swivel bearings. Findings -The new system was successful, robust and was not affected by changeable parameters. The simple systems assisted hand truck operators in steering their forklifts across sloping ground without veering off course. The systems overcame the problems associated with forklifts that steer using two swivelling wheels and meant that less work was required from hand truck operators as their forklifts tended to travel in the desired direction Research limitations/implications -Experiments demonstrated that calibrating forklift controllers for straight-line balance and optimizing motorcompensation did not solve this problem. Instead, swivelling wheel angle was selected to provide feedback. At the point when veer is first detected, a forklift has already begun to alter course and the job of the correction system is to minimize this drift from the desired course. Practical implications -The forklifts and pallet jacks often steer by having swivelling wheels but problems with this configuration occur when a forklift is driven along sloping ground because they can swivel in the direction of the slope. Gravity then causes the forklift or pallet jack to start an unwanted turn or "veer" and the vehicle goes in an unintended direction. This situation is exacerbated for vehicles with switch controls, as switches cannot provide fine control to trim and compensate. Originality/value -Each year in the United States, over 100 employees are killed and 36,000 are seriously injured in accidents involving forklift trucks and pallet carriers. This is the second leading cause of occupational fatalities in "industrial" type workplaces. The research aims to make the use of this type of equipment safer and the systems can be attached to many standard forklifts and pallet jacks.

The effect on completion of mobile-robot tasks is investigated depending on how a human tele-operator interacts with a sensor system and a mobile-robot. Design/methodology/approach: Interaction is investigated using two mobile-robot systems, three different ways of interacting with the robots and several different environments of increasing complexity. In each case, the operation is investigated with and without sensor systems to assist an operator to move a robot through narrower and narrower gaps and in completing progressively more complicated driving tasks. Tele-operators used a joystick and either watched the robot while operating it, or sat at a computer and viewed scenes remotely on a screen. Cameras were either mounted on the robot to view the space ahead of the robot or mounted remotely so that they viewed both the environment and robot. Every test was compared with sensor systems engaged and with them disconnected. Findings: A main conclusion is that human tele-operators perform better without the assistance of sensor systems in simple environments and in those cases it may be better to switch off the sensor systems or reduce their effect. In addition, tele-operators sometimes performed better with a camera mounted on the robot compared with pre-mounted cameras observing the environment (but that depended on tasks being performed). Research limitations/implications: Tele-operators completed tests both with and without sensors. One robot system used an Umbilical Cable and one used a radio link. Practical implications: The paper quantifies the difference between tele-operation control and sensor assisted control when a robot passes through narrow passages. This could be useful information when system designers decide if a system should be tel-operated, automatic or sensorassisted. The paper suggests that in simple environments then the amount of sensor support should be small but in more complicated environments then more sensor support needs to be provided. Originality/value: The paper investigates the effect of completing mobile-robot tasks depending on whether a human tele-operator uses a sensor system or not and how they interact with the sensor system and the mobile-robot. The paper presents the results from investigations using two mobilerobot systems, three different ways of interacting with the robots and several different environments of increasing complexity. The change in the ability of a human operator to complete progressively more complicated driving tasks with and without a sensor system is presented and the human teleoperators performed better without the assistance of sensor systems in simple environments.

Powered-wheelchair transducers and systems are presented that provided more control, reduced veer on slopes, and improved energy conservation, while reducing effort. They are especially significant for people with movement disorders who lack sufficient hand-grasp and release ability or sufficient targeting skill to use joysticks. Design/methodologies/approach Laboratory test rigs were created to test the proportional switches and to teach potential users. Then a rolling road was created and trials were conducted with the road and real situations. Caster angle measurement was selected to provide feedback to minimize drift away from a chosen course and an electronic solution was created to match driver control to caster steering position. A case study is described as an example. Findings Results and advantages are presented from changing from using a set of digital-switches on a wheelchair to a set of new variable-switches and then adding a sensor system to prevent veer on slopes. The systems have been tested for more than 18 months and shown to assist powered-wheelchair users with poor targeting skills. Research limitations The research used typical wheelchairs with caster wheels but systems could easily be used on other wheelchairs. Practical implication Simple input-devices are presented that isolate gross motor function and are tolerant to involuntary movements (proportional-switches). A sensor system is presented that assists users in steering across sloping or uneven ground. Originality/Value The proportional-switches and sensors were shown to reduce veer and to provide more control over turn and forward speed and turn radius while reducing frustration and improving energy conservation. The simple and affordable systems could be created and attached to many standard powered-wheelchairs in many organisations.. The powered-wheelchair users became more independent when using the new systems.