Drop the Joystick
The first new way to control electric wheelchairs since they were invented more than 70 years ago.
Piher Sensors and Controls met the electronic sensor input requirements needed for the redesign of the revolutionary JoyBar, an intuitive control for electric wheelchairs developed by Active Controls. The original JoyBar model was a vast improvement over the traditional Joystick control, which had been notorious for being extremely difficult to operate.
However, the first JoyBar could not accommodate more than one output function (ability to control steering or acceleration on the wheelchair), which did not meet requirements for severely disabled persons and Medicare funding in the U.S. market. It also did not meet new regulations in Europe that mandates redundant (dual independent) outputs to safeguard against runaway wheelchairs.
To solve these issues, Active Controls developed the Enhanced JoyBar using Piher’s redundant, non-contacting rotary sensor technology to replace the analog (single output) potentiometric circuitry design of the original model.
After some research, the Active Controls engineering team found that the PSC-360 Hall Effect Sensor would provide the entire solution. In addition to the sensor providing redundant sensing and capabilities for control of two outputs, it also enables the bar to be compatible with many of the existing controllers that have unlimited actuator functions.
Size-wise, the PSC-360 was a simple drop-in-place solution, easily fitting into the existing hand control. It required minimal tooling to make up for the slightly larger space than the previous analog sensors originally designed for the unit.
The PSC-360 has a permanent magnet as the only moving component, making it extremely durable with a long service life of up to 50 million cycles. Further durability is incorporated with the fully sealed magnet and the sensor’s electronics (sensing system) encapsulated in molded plastic, providing a completely sealed, IP67 rated sensor.
“The PSC-360 not only solved the actuator issue, it was also a good fit for our needs,” recalls the owner of Active Controls, LLC, Michael Flowers. “Two Piher PSC-360 Sensors are used in each digital JoyBar to separate and control the two inputs, thereby maintaining the ‘intuitive’ feel of the original JoyBar design that used two separate analog sensors.”
Each electronic sensor’s range is programmed differently – one addresses the degree of movement needed for the handlebar sweep (steering) and the other addresses the smaller degree of movement needed for the throttle (direction and speed control) sweep.
Not only does the PSC-360 allow the JoyBar to comply with the insurance reimbursement regulations for control of more than two outputs, it also provides the users with more precise control which results in smoother operation of the electric wheelchair.
Another unexpected benefit was also derived. By selecting the PSC-360, the Enhanced JoyBar’s entire system became fully compatible with many of the existing digital motor controllers already in use on current wheelchair designs, making integration much easier for electric wheelchair dealers and manufacturers.
“We were pleasantly surprised to find that with Piher’s electronic sensor, the Enhanced JoyBar could now interface with a series of existing electric wheelchairs and their electronic controllers,” explains Flowers. “For electric wheelchairs with these controls, there would be no need to change out that component like we had to do with the analog sensors.”
Despite the original JoyBar’s breakthrough innovation in wheelchair technology – the first new way to control electric wheelchairs since they were first invented more than 70 years ago – getting the industry to adopt the technology has been slow. The issue was that the original unit required changing the controller module, but new digital technology is compatible with many existing controllers.
Before the new design, wheelchair manufacturers and dealers required special programmers to set custom parameters to meet individual needs. Programmers can now adjust chairs to be more responsive, less responsive, stop faster, or stop more slowly.
Individualized programming can even provide a dampening function to prevent tremors of a Parkinson’s patient from engaging speed or turning. The controller manufacturers have designed a different programmer for each of their controllers to achieve these customizations.
Dealers use the controller-specific programmers to dial in exactly the performance that a consumer needs.
To date, many of the electric wheelchair manufacturers have been unwilling to offer the original JoyBar, because it would require an additional investment, not only in training people on how to use new programmers, but also capital costs of subsidizing programmers for their dealers.
“With the use of the PSC-360 digital sensors, there is no need for most of the manufacturers to invest in changing controllers – the Enhanced JoyBar is now compatible with many of the existing controllers and electronics,” sums up Flowers. “With the new ease of incorporating this technology, intuitive control should become much more accessible for people with disabilities who need it”.