Posted to News on 18th Dec 2023, 15:00
Low-cost inductive sensors give agriculture the ‘X-Tractor’
Modern agriculture is increasingly adopting automation technology and Contrinex sensors. For example, the low-cost, yet robustness and reliability of Contrinex's rugged 600 Series' inductive sensors are trusted on a range of innovative tractors.
The sensors are part of the tractor's ability to offer all-wheel steering for manoeuvrability, for example, whilst working in small spaces, and two-wheel steering for driving at higher speeds, on-road for example.
The robustness and long sensing range of the sensor enables it to reliably verify that the rear axle is locked in the straight-ahead position before activating the higher-speed, two-wheel steering function.
A range of tractors offer a combination of high manoeuvrability at low speed and higher speed for on-road use by providing all-wheel drive with a choice to switch between front and all-wheel steering.
The reliability and performance of a tractor are essential to a farm's success, especially during times like harvest, when they can be working 18 hours or more over consecutive days. Therefore, this application needs to provide reliability on a tractor that works all types of terrain and in all weather conditions.
All-wheel steering is advantageous both on extreme terrain and where increased manoeuvrability is required, for example, loading and unloading in farmyards or barns. However, the default two-wheel steering configuration using the front wheels is best suited for faster driving, for example hauling a trailer on the road, where the rear axle is locked in the straight-ahead position to prevent misalignment of the rear wheels.
A rugged, reliable and accurate sensor system is required to detect the straight-ahead position of the rear axle before it is locked. The sensor must withstand significant mechanical shock and vibration and be impervious to water ingress. Additionally, it should accommodate the extremes of temperature experienced during all-year-round operation.
Contrinex's 600 Series' of inductive sensors meet the needs of cost-sensitive applications, with their robust reliability enabling them to accommodate the required extremes of temperature, shock and vibration. The sensor has a V2A/AISI 303 stainless-steel body with vacuum-encapsulated electronics, and it is rated for operation at temperatures between -25C and 70C.
An M8-sized sensor was selected and is mounted immediately below one end of the vehicle's hydraulic power-steering steering rack. It detects the position of a narrow flange and its sensing distance of 2mm eliminates accidental collision with the flange as it passes the sensing face.
The sensor selected has a PNP output with an integral M8 connector and is connected to the vehicle's central controller via a flexible PVC-sheathed cable. Adding the sensor requires minimal modification to the vehicle's control systems, and maintenance is simple and speedy.
The sensor detects the straight-ahead position of the vehicle's rear axle repeatably and accurately, ensuring the correct, reliable engagement of two-wheel steering. Contrinex inductive sensors provide the customer with a cost-effective fit-and-forget solution to a challenging problem.
