Off-Highway Vehicles: Torque from Lab Out into the Field

The primary challenge for off-highway vehicles is to work efficiently, whatever the terrain.

Rising fuel prices and the operators’ desire for lower costs have prompted vehicle manufacturers to design ever more economical vehicles with higher efficiency and reduced emissions. Many vehicles now automatically monitor and optimise effectiveness while the vehicle is being operated to ensure maximum efficiency.
The combination of real-time force measurements with Internet-of-Things commmunication, plus ruggedised on-board computing with Artificial Intelligence software, paves the way for Autonomous Vehicles in Farming and Mining.

The OEM Sensors team at HBK plays a key role in these advances by providing the data that feeds the control loop. Since standard Sensors are seldome available in the size or format that Design Engineers require for a new vehicle, they turn to HBK for the design and custom sensors.

The purpose of a tractor is the same today as it was in the 19th century, when the first steam-powered machines were developed: to deliver high power, traction and torque at a controllable speed. Over time, the design has evolved and expanded into a wide range of off-highway vehicles that perform critical functions in a wide variety of industries. Whether they are used in agriculture or earth moving, in commercial or military applications, the primary challenge for these vehicles is to work efficiently, whatever the terrain.

To perform at their best, the wheels of these heavy, off-highway vehicles must stay in constant contact with the ground. And to do this, the power from the engine must be delivered consistently through the drivetrain and the gearboxes to all the wheels. For example, a tractor specifically designed to reduce wheel slip will combine an efficient engine and drivetrain system that sees very little power loss to the wheels, the power take-off (PTO) or the implement. Why go to all that effort?
Because improvements in operational efficiency improve safety and reduce accidents; increase work rates and optimise profit for the operator.

Rising fuel prices and the operators’ desire for lower costs have prompted manufacturers to design ever more economical vehicles with higher efficiency. At the same time, governments around the world are setting stricter fuel efficiency standards for both on-highway and off-highway vehicles to reduce vehicle emissions.

Attaining these goals delivers benefits for both the environment and vehicle operators. Since 2019, manufacturers of diesel-powered engines, transmissions, gearboxes and axles have all focused on engineering new products that exceed the Final Tier 4 emissions standards introduced between 2013 and 2015. The manufacturers work in conjunction with the makers of agricultural, construction and other off-highway vehicles to ensure the final product now meet the even tougher requirements of Stage V regulations that both consumers and governments demand.

Torque transducers offer another approach to measuring torque that employs the same principles as strain gage measurement. However, a torque transducer is a highly precise machined element that’s installed between two components of the system at the point at which the torque is to be measured. This transducer is specifically designed to focus the rotational force and torque being applied directly at sensing areas where the strain gages are located. Torque measurement instruments used to be expensive, bulky and sensitive which made them suitable only for laboratory testing purposes. However improvements in reliability and ruggedisation have enabled vehicle, engine and driveline component manufacturers to incorporate factory-installed, production-level torque measurement directly into their vehicles.

By combining live force measurements with Internet-of-Things commmunication, and ruggedised on-board computing with Artificial Intelligence software, vehicle management systems can not only sense power loss or gain at various stages of the driveline, the wheels and the implements, but also make adjustments automatically and in real time. The short term effect of the feedback loop is reduced stress onvehicle components, which avoids catastrophic failure. Long term the feedback loop optimises maintenance cycles, increases overall efficiency and reduces cost of ownership.

All of which paves the way for the newest stage in efficiency gains: the autonomous farming vehicle. In this economic model, one operator can control multiple autonomous vehicles remotely at the same time. No surprise then, that the demand for Autonomous Farm Equipment is set to expand rapidly.The global value of US $ 65 billion in 2020, is estimated to grow at 12% per annum, reaching US $ 135 by 2026.).

Although smaller, at US $ 2.3 billion in 2020, even faster growth – 23% per annnum is predicted for the global Autonomous Mining Vehicles market.

As the demand for higher performance from off-highway vehicles grows, the autonomous vehicle industry will see further advances in vehicle design, system maagement and still wider adoption. This in turn enables the off-highway industry to make further progress in the quest for lower emissions, fuel savings and vehicle stability control.

The OEM Sensors team at HBK plays a key role in these advances by providing the data that feeds the control loop. Since standard Sensors are seldome available in the size or format that Design Engineers require for a new vehicle, they turn to HBK for the design and ustom sensors.

HBK engineer adapt the design of individual components like flex plates, drivetrains, gear wheels or axles: they design custom strain gages and incorporate these into the components so that they become functional sensors that accurately measure torque, pressure, force or load. By embedding a telemetry board or induction ring into the components themselves, data can be transmitted wirelessly to the vehicle management system.
Vehicle manufacturers around the globe rely on our engineers to design sensors that meet their specific requirements; and on HBK manufacturing facilities on three continents to deliver the required volume, at the desired quality, on time.

Footnote:

• January 2022 - Global Autonomous Farm Equipment Market to Reach US$135.4 Billion by the Year 2026