Some of the smallest motors can be found in the defence industry, where precision, efficiency, reliability and compactness are essential. Here, Stewart Goulding, managing director of precision drive system supplier EMS Ltd, explains why small precision motors are essential for defence manufacturing and development.
The defence industry is a valuable part of the UK economy. The UK is the third largest buyer of defence equipment in the world and in 2017, UK defence exports were worth £9 billion to the economy.
UK Defence needs equipment that is precise, long-lasting and capable of operating in the most extreme environments, such as remotely operated vehicles (ROVs), optical reconnaissance equipment and battery-powered air purifying respirators (PAPRs).
Remotely operated vehicles (ROVs) are primarily used for bomb disposal and feature robotic arms designed to handle the suspected bomb. This process requires immense dexterity and precision to allow the operator to delicately manoeuvre the ROV, pick up the package and carry out the bomb disposal. To achieve this, each axis of the robotic arm is fitted with compact and precise motors.
Using motors with a high power-to-weight ratio also helps keep the weight of the ROV down, allowing it to traverse tough terrain while improving operational-time by reducing the load on the onboard battery.
Optical systems are used by military personnel to carry out reconnaissance that helps them gather potentially life-saving intelligence. Here, the optical system depends on compact and precise motors to deliver the zoom, focus and pan and tilt functionality required to gather high quality images and video.
Breathing apparatus such as PAPRS is used in environments affected by life-threatening chemical attacks or outbreaks of disease where it is not safe to breathe the air naturally. Powered by a motor, the fan filters dangerous gases and bacteria out of the environment and forces clean air back into the mask.
If the motor is faulty and stops working, it could result in potentially life-threatening consequences for the person wearing the apparatus. A motor with a high power-to-weight ratio also ensures that the equipment is wearable and light.
Missile Guidance
In October 2018, a paper was published in Defence Industry Bulletin, which discussed turning simple rockets into smart missiles. The paper reported that technological developments and miniaturisation mean that small laser-seekers in unguided munition system can now be incorporated, giving them guided capabilities.
One of the first to adopt this technology was the French missile industry. This allowed them to transform the nation’s ageing systems in 2005. The warhead and guiding system are fitted onto a miniaturised motor, making the system more compact and more efficient than many American counterparts.
Micromotors with high power ratios and levels of reliability are crucial to this transformation as they allow for finer and more precise movements in the missile guidance systems, all while maintaining the smaller sizes. This means that the ordinance can move with high levels of precision, allowing the rockets to accomplish missions accurately even at high performing vectors.
Exoskeletons
An exoskeleton is a wearable suit powered by a combination of electric motors, levers, hydraulics and pneumatics, that provides limb movement with more strength and endurance limits for the wearer.
According to 360 Market Updates, the military exoskeleton industry across the aerospace and defence sector is expected to grow by 65 per cent by 2023.
An exoskeleton could be likened to a sort of mechanical armour. Sensors are fitted to the structure and record the movements of the soldier wearing it. The information collected is transmitted to the machine’s mechanised muscles, or electric motors that power the soldier’s movement.
All the motors in the machine must be synchronized to enable it to optimise and balance a soldier using postural recognition capacity — or the machine’s ability to interpret the position the user wants to adopt.
Sizing Precision Motors
While these examples describe a limited number of defence scenarios, they illustrate the need for small, powerful, precise, reliable and efficient motors across the sector.
Whatever the application, sizing precision motors necessitates gathering data like payload, speed and acceleration, amongst others, accompanied by calculations using specific units of measurement.
It requires an in-depth understanding of maximum speed, load torque and moment of inertia. Moment of inertia is the force required to overcome load resistance and to move it. It quantifies load resistance as angular acceleration; the rotational motion equivalent of mass (force x acceleration) in Newtonian linear motion calculations.
Using a supplier like EMS can ensure that UK industry continues to deliver defence equipment capable of saving lives. EMS is the sole UK supplier of high-quality precision micro-drive systems from FAULHABER. The high power-to-weight ratio, reliability and incredibly small size of the FAULHABER precision motors makes them ideal for the defence industry. In particular, DC, Brushless DC and stepper motors can be used in ROVs, optical systems and breathing apparatus.
To ensure optimal performance and safety, it’s vital that original equipment manufacturers in the defence sector use high precision, reliable and efficient motors. Using a supplier like EMS can ensure that the UK continues to deliver defence equipment capable of saving lives.
