Microsoft patents a mixed reality glove with haptic feedback system
Mixed reality and virtual reality systems provide immersive audio-visual experience but fail to provide a satisfying tactile (touch) experience where virtual objects feel like real objects.
To solve this problem, Microsoft came up with a haptic feedback system that can be worn by the user on the hand. The patent application is published on January 3rd, 2019.
The haptic feedback system comprises of a glove with a circuit and a controller. The glove has electrorheological fluid with adjustable viscosity. The circuitry and controller change the viscosity of the fluid based on the input. The following image from the patent shows the haptic feedback system (16) worn by the user on the hand.
The image shows a head mounted display (14) with loudspeakers (23) and a virtual display object (28). The virtual display object is projected into a field of view of the user.
Whenever the hand of the user intersects the virtual display image, the haptic feedback system provides a contact sensation. This sensation is provided by a piezoelectric or voice-coil type actuator by applying pressure to the skin in the contact vicinity. The computing device attached to the HMD determines when to apply the pressure. The patent description says that this aspect alone of simulating touch is not sufficient to provide a satisfactory touch sensation. A resistive effect of object on the user’s skeletal joints is also required.
“Although skin-pressure simulation portion 30A may simulate the sensation of the touch of a virtual object on the user’s skin, this aspect alone may not provide a satisfactory contact sensation, as it would not offer a resistive effect of object contact on the user’s skeletal joints. Contact with an actual solid object, by comparison, would result in the sensation of kinematic resistance to attempted movement through the object, which would be felt at the joints. For example, the joints of the fingers, in attempting to move the fingers through a solid object, would experience at least some reactive force from the object, with reference to Newton’s third law.“Patent application 20190004602
Here comes the actual invention of Microsoft. To simulate the resistive effect, a fluidic channel, a circuit and a controller are arranged in a glove worn on the hand.
“1. A haptic feedback system, comprising a wearable device configured to be worn by a user, the wearable device including a fluidic channel; a fluid disposed within the fluidic channel, the fluid including an adjustable viscosity; a circuit configured to vary a field within the fluidic channel; and a controller configured to receive a first input, and in response to receiving the first input, apply a first field within the channel via the circuit to set the adjustable viscosity of the fluid to a first viscosity; and receive a second input, and in response to receiving the second input, apply a second field within the channel via the circuit to set the adjustable viscosity of the fluid to a second viscosity.“Claim 1 of the patent application 20190004602
The following image from the patent shows the glove which provides mechanical resistance to hand movement.
The glove has fluidic channels (202A & 202B) filled with electrorheological fluid. This fluid has electrically adjustable viscosity. By changing the electric field applied to the fluid, the viscosity can be adjusted. The circuitry (204) and the controller (210) vary the electric fields to change the fluid viscosity and hence simulate a resistive sensation in the joints against the virtual object.
In figure 3A of the patent, a relatively small force is being applied to the virtual object which is shown as a spring. This signal is applied as a first electric field to the fluidic channels (202) which changes the fluid viscosity to keep the finger straight. In figure 3B of the patent, the spring is further compressed by applying a larger force and a second electric field is applied to the fluidic channels (202). This changes the fluid viscosity to make the finger bent. The user can thus experience a lifelike touch sensation.
The process of providing the haptic feedback is shown in the figure from the patent
How is the gaming experience going to change with this invention?