Magnetic-repulsion load-sensing human interface device
The magnetic repulsion-based control mechanism addresses the precision and intuitiveness issues of traditional joysticks by using load cells and repelling magnets to achieve smooth and accurate movements in complex three-dimensional environments.
Patent Information
- Authority / Receiving Office
- GB · GB
- Patent Type
- Applications
- Current Assignee / Owner
- PORTAZIER ROBERT
- Filing Date
- 2024-11-21
- Publication Date
- 2026-06-24
AI Technical Summary
Traditional joystick controls for virtual environments and physical space lack precision and intuitiveness due to their reliance on potentiometers or Hall-effect sensors, which struggle with smooth, repeatable motions, especially in three-dimensional spaces, and mechanisms like stiff-stick controls and foot pedals offer limited improvements.
A magnetic repulsion-based control mechanism using load cells and repelling magnets to provide a non-linear, intuitive control experience by leveraging the exponential increase in repulsive force as magnets approach each other, allowing for smoother and more accurate movements.
The device enables precise and natural control in applications requiring fine-tuned movements, such as robot arm manipulation and virtual camera operation, by translating small distance changes into significant force variations.
Smart Images
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Abstract
Description
This invention relates to a Human Interface Device (HID) for controlling movement in both virtual environments and physical space. Introduction Traditional joystick controls rely on potentiometers or Hall-effect sensors to measure angular deflection, which is good for fast movement control, but it is difficult to produce smooth, repeatable motions using these technologies, especially when controlling complex systems in three-dimensional space such as robot arms or virtual cameras. The inherent innaccuracy of human limb positional perception and the limitations of these existing control mechanisms make this particularly challenging. In other words, when pushing or pulling an object humans are relatively poor at judging small changes in distance, but they are very good at judging small changes in load. Background Joystick controls typically use a spring-loaded mechanism to return the stick to its centre position. While this provides a constant opposing force, it can hinder precise control, as the output signal is only proportional to the distance from the centre, not the amount of force applied. This makes it difficult to achieve consistent and repeatable movements. Alternative control devices, such as stiff-stick controls and load-cell foot pedals, have been introduced to address these limitations. While they offer improved control over traditional joysticks, they often suffer from non-intuitive operation or limited functionality. Stiff-stick controls can be difficult to gauge and repeat the force applied, and foot pedals are typically limited to single-direction control, accounting for only 50% of an axis of movement. To overcome these drawbacks, this invention utilises the non-linear nature of magnetic repulsive force to provide a more intuitive and precise control mechanism. By exploiting the exponential increase in repulsive force as repelling magnetic poles are brought closer together, the device offers a more natural and responsive control experience. As two repelling magnetic poles are brought closer together, the repulsive force between them increases non-linearly. This means that a small change in distance can result in a significant change in the repulsive force. Consequently, to move the magnets closer together by a given amount, progressively more force is required, which is quite easy to judge. This innovative approach allows for smoother, more accurate movements, particularly in applications requiring fine-tuned control, such as robot arm manipulation and virtual camera operation Using this device as a form of robot or virtual camera control is similar to physically pushing an object like a camera dolly or camera crane, and therefore very intuitive for the user. The harder you push it, the faster it will go. Another advantage of this type of control device is that even when it has reached its maximum range of travel, the load applied could still be increased if the load sensitivity was set beyond the repulsive force of the magnets. The repelling magnets can also be electromagnets, meaning the repulsive force can be variable. The present invention takes advantage of these facts to make a very intuitive and novel form of Human Interface Device (HID) Statement of Invention A load cell is connected to a lever that pivots around a fixed fulcrum. The load cell’s free end has powerful magnets on either side, that are positioned equidistant between two repelling magnets, arranged such that their repelling poles face each other. When a load is applied to the lever, it rotates around the fulcrum, bringing the load cell closer to the repelling magnets. This increases the repulsive force between the magnets, which is detected by the load cell’s strain gauges. As the load is removed, the lever returns to it’s original position, and the repulsive force diminishes, resulting in a neutral reading. By adjusting the distance between the repelling magnets on the arc of travel, the range of travel can be modified. This invention utilises pre-existing bidirectional load cells, which consist of a metal bar with strain gauges on either side. These strain gauges measure minute changes in the bar’s straightness, generating an analogue signal. This signal is then converted to a digital format and amplified, ultimately producing a calibrated output that can be interpreted as a Human Interface Device (HID) joystick signal. Optional Features The lever may be a long vertical stick. The lever may be a rotary dial The lever may be a bi-directional foot pedal. The load cell may rotate with the lever and the repelling magnets remain fixed against it. The load cell may remain fixed, and the repelling magnets rotate against it. The repelling magnets may be fixed-strength magnets. The repelling magnets may be variable-strength electromagnets. Introduction to figures. Figure 1 to Figure 4 show the lever 1 as a long vertical stick that is mounted on a desk at waist height and is pushed and pulled by the operator. The load cell 3 moves with the lever 1 whilst the repelling magnet holders 7 remain stationary.. Figure 5 to Figure 15 show the lever as a hand-held dial 9 that is rotated around the load cell 3. In this case the load cell 3 remains stationary and the repelling magnets 11 are moved against it. Figure 17 to Figure 23 shows the lever as a bi-directional foot pedal 17 that has adjustable angle and range of travel. The load cell 3 remains stationary and the repelling magnets 20 are moved against it. Detailed Description In Figure 1 the device is fixed by clamping the baseplate 2 to a static surface. The vertical stick 1 rotates around the fulcrum 4. The baseplate 2 is made of folded sheet aluminium such that there has minimal flex and is non-ferrous so that it does not exert sideways forces upon the powerful neodymium magnets 5. In Figure 2 the vertical stick 1 is shown in the backwards and forwards positions. The load cell 3 rotates on the opposite side of the fulcrum 4, and gets closer to the repelling magnet holders 7. These have an adjustable position using the radial slots 6 that will increase / de-crease the range of travel and can be locked into place using the machine screws 8. In Figure 3 the load cell 3 has neodymium magnets 5 attached on either side via the load cell magnet holder 6. This is made of 3D printed plastic to account for the specific shape needed to hold them perpendicular to the arc of travel. In Figure 4 the load cell 5 rotates around the fulcrum 4, so that the neodymium magnets 5 in the magnet holder 6 is on the same arc of travel as the neodymium magnets 5 in the repelling magnet holders 7, and perpendicular to the arc of travel, which means the magnetic poles are in exact opposition as they get closer to each other. This exerts the maximum amount of repulsive force on the load cell, and ensures the force is uniform so that the load cells give accurate consistent reading. The repelling magnets 5 can also be replaced with electromagnets in this version, which would allow the repulsive force to be variable. In Figure 5 and 6, the load cell 3 is contained within a rotary dial 9 that can be rotated around a fulcrum 4 that is attached to a fixed bracket 10. These are made of 3D printed plastic to account for the specific shape needed to hold them in position. In Figure 7 the load cell 3 is in the equidistant position between the repelling magnet holders 12. In Figure 8 the rotary dial is rotated all the way anti-clockwise so that the repelling magnet holders 12 are exerting maximum force on the load cell 3. In Figure 9 the rotary dial is rotated the maximum amount clockwise so that the maximum force is being exerted on load cell 3 in the opposite direction. In Figure 10 the repelling magnet holders 12 have been positioned closer together so that the range of travel has been minimised. In this position the force on the load cell 3 would still be neutral, until the rotary dial 9 was rotated in either direction. In Figure 11, the neodymium magnets 11 are bolted directly to the load cell 3, which reduces the amount of space that is needed, but these are not perpendicular to the arc of travel. In Figure 12 the repelling magnet holders 12 are mounted on the rotary baseplate 15. Figure 13 is a crop view showing the repelling magnet holder 12 at an angle such that they are parallel to the neodymium magnets 11 on the load cell 3 when they are at their closest position. This means that the force exerted on them is as uniform as possible. In Figure 14 the repelling magnet holders 12 have a radial groove 13 underneath that makes it easy to adjust their position on the rotating baseplate 15. In Figure 15 the rotating baseplate 15 has radial slots 16 through them which the machine screws 14 clamp the repelling magnets holders 12 in place once they have been adjusted to the required range of travel. Figure 16 is the rotary dial 9 that encloses the whole mechanism and acts as the handheld grip that is used to physically rotate the device. This is 3D printed in plastic so that the shape can be customised to suit specific requirements. In Figure 17 the load cell 3 is stationary and the repelling magnets 5 are connected to a footplate 17. This rotates around the fulcrum 4 which is positioned between a pair of A-frames 18 that are mounted onto a baseplate 19. The neodymium magnets 5 have an adjustable range of travel using the repelling magnet holders 20. In Figure 18 the footplate 17 is at it’s most clockwise position so the load cell 3 has maximum force exerted against it in one direction. In Figure 19 the footplate 17 is at it most anti-clockwise position so the load cell 3 has maximum force exerted against it in the opposite direction. In Figure 20 the top half of the load cell 3 is clamped to the A-frame 18. The neodymium magnets 5 are held to the load cell 3 using magnet holders 21 which position them perpendicular to the arc of travel. In Figure 21 the repelling magnet holders 20 are attached to the footplate 17 using machine screws 22 so that the angle of the footplate 17 can be adjusted for user comfort. Once secure, the footplate 17 can be actuated with heel and toe, and the repelling magnet holders 20 push the neodymium magnets 5 together so that the repulsive magnetic forces act against the load cell 3 as uniform as possible. In Figure 22 and 23 the repelling magnet holders 20 can be adjusted to set the optimal range of travel. These parts are made of 3D printed plastic to account for the specific interlocking shape. The three types of devices detailed in the description show the variety of ways this technology can be applied. All of these devices are designed to control a single-axis of movement, but it is intended that a user could combine multiple types of device to control the linear X, Y and Z axes of movement in a virtual environment or using a robotic arm.
Claims
1. An load-sensing device that uses the magnetic-repulsive force to act against a load cell, such that the closer the repelling magnetic poles, the more force is acted upon the load cell, with the intention of converting the load applied into a Human Interface Device (HID) output signal2. A Human Interface Device (HID) according to claim 1 that is based upon a load cell that is situated between two pairs of repelling magnetic poles such that it outputs zero signal at rest and can output a positive and negative Human Interface Device (HID) signal when actuated forwards and backwards from the zero position.
3. A variable Human Interface Device (HID) according to claim 2 with adjustable range of travel by moving the repelling magnets closer and further away from the zero position around the arc of travel.
4. A lever according to claim 2 that rotates around a fulcrum and utilises leverage to act against the repulsive force of repelling magnetic poles, such that the force exerted upon the load cell is uniform, as the magnets are perpendicular to the arc of travel.
5. A rotary dial according to claim 2 that rotates around a fulcrum and utilises leverage to act against the repulsive force of repelling magnetic poles, such that the force exerted upon the load cell is uniform, as the magnets are parallel at their closest position.
6. A bi-directional foot pedal according to claim 2 that rotates around a fulcrum and utilises leverage to act against the repulsive force of repelling magnetic poles, such that the force exerted upon the load cell is uniform, as the magnets are perpendicular to the arc of travel.AMENDMENTS TO THE CLAIMS ARE FILED AS FOLLOWS:30 07 25Claims (Amended 30 / 07 / 2025)1. A Human Interface Device (HID) for sensing load, comprising:a. a lever configured to pivot around a fulcrum;b. a load cell mechanically coupled to the lever, said load cell comprising strain gauges;c. a first set of 2 magnets physically coupled to either side of the load cell;d. a second set of 2 opposing magnets, stationary relative to the fulcrum, arranged to repel the first set of magnets;e. wherein the application of a load to the lever causes the lever to pivot, thereby moving the first set of magnets closer to the second set of magnets, increasing the repulsive force between them;f. wherein the increased repulsive force is detected by the load cell’s strain gauges, generating an analog signal; andg. a converter and amplifier configured to transform the analog signal into a calibrated digital output, interpretable as a human interface device signal, wherein the output signal is zero when no load is applied and the lever is in a rest position, and the signal is positive or negative depending on the direction of the load applied from the rest position.
2. A variable Human Interface Device (HID) according to claim 1 with adjustable range of travel by moving the repelling magnets closer and further away from the zero position around the arc of travel.
3. A lever according to claim 1 that rotates around a fulcrum and utilises leverage to act against the repulsive force of repelling magnetic poles, such that the force exerted upon the load cell is uniform, as the magnets are perpendicular to the arc of travel.
4. A rotary dial according to claim 1 that rotates around a fulcrum and utilises leverage to act against the repulsive force of repelling magnetic poles, such that the force exerted upon the load cell is uniform, as the magnets are parallel at their closest position.
5. A bi-directional foot pedal according to claim 1 that rotates around a fulcrum and utilises leverage to act against the repulsive force of repelling magnetic poles, such that the force exerted upon the load cell is uniform, as the magnets are perpendicular to the arc of travel.