Invacare LiNX - What is dynamic and adaptive load compensation?

Powerchair users often have great difficulty when turning slowly on soft surfaces such as a rug. This results in the castors locking followed by a sudden jolt when they finally release. Another concern is accurate low speed control for example, while going through doorways or approaching a table as a number of corrective actions are needed to get the powerchair to the correct position. Lastly there is the poor slope hold which when the chair stops can cause it to slightly roll back when the user starts driving again. This can leave the user feeling nervous and lacking confidence in the powerchair.

Through research it became clear there is a relationship between speed and resistance. For example, when a powerchair goes over a rug the speed is low but the resistance level is high as it is a challenging surface. When a powerchair travels along a flat path the speed is high but the resistance low. The powerchair needs to be able to adapt to each situation to give the user a smooth and comfortable drive experience. This is exactly what dynamic load compensation has been designed for.

Built into the new Linx system, the innovative technology ensures motor resistance levels are set correctly for the user, allowing for more accurate control. When going through doorways or approaching tables its predictable low speed control makes it a simple and straightforward process. It also allows the user to drive with confidence on any surface, camber or incline, with improved hold on slopes and reduces the effect of castor lock on soft surfaces, keeping both speed and direction constant.

Load compensation is usually set during the manufacturing process and is rarely changed in the field due to the need of an experienced technician and the difficulty in getting it right. As a powerchair ages the ideal value of load compensation changes, due to the motors bedding in or wearing out, which means the drive experience changes and varies for the user over time. Being able to offer a constant, predictable driving experience for the user over the lifetime of the powerchair was paramount when developing Linx and so adaptive load compensation was designed and added to the system.

This technology gives the powerchair the intelligence to learn the best value by constantly measuring the motors whenever the powerchair is being driven. It then uses the measurements to make small adjustments to the load compensation value being used. Also, if a motor needs to be replaced the powerchair will learn the resistance of the new motor and even if the resistance of each motor is significantly different the powerchair will drive as if it had two motors the same age. This is accessible through the fast learn function in the LiNX programming App. All the user notices is the powerchair performs the same as it did on day one.
The innovative dynamic and adaptive load compensation technology in Linx has been designed with users, dealers and therapists in mind. The new insight driven control system learns over time, bringing with it a revolutionary driving experience.