Ultrasound time-of-flight sensor module, ultrasound absorption sensor module, tactile-sensing systems, and related methods
An ultrasound time-of-flight (TOF) sensor module includes an ultrasonic transducer device, a cover layer, an elastic member, and a signal processor electronically coupled to the ultrasonic transducer. The ultrasonic transducer device includes at least one ultrasonic transducer, which is configured as an ultrasonic transmitter and/or an ultrasonic receiver. The elastic member is interposed between the ultrasonic transducer device and the cover layer. The elastic member undergoes reversible compression in response to an external object impacting and/or contacting the cover layer. An ultrasound propagation distance between the ultrasonic transducer and the cover layer varies in accordance with the compression. The ultrasonic transmitter(s) transmit ultrasound signals. The cover layer reflects a fraction f of the ultrasound signals incident thereon. The signal processor obtains TOF data which indicate time differences between times of transmission of transmitted ultrasound signals by the ultrasonic transmitter(s) and times of receipt of reflected ultrasound signals by the ultrasonic receiver(s). The time differences vary in accordance with the ultrasound propagation distance.
1 . An ultrasound time-of-flight sensor module, comprising:
an ultrasonic transducer device comprising at least one ultrasonic transducer, each ultrasonic transducer being configured as an ultrasonic transmitter and/or an ultrasonic receiver;
a cover layer;
an elastic member interposed between the ultrasonic transducer device and the cover layer and mechanically coupled to the cover layer and to the ultrasonic transducer device; and
a signal processor electronically coupled to the ultrasonic transducer;
wherein the elastic member undergoes reversible compression in response to an external object impacting and/or contacting the cover layer, an ultrasound propagation distance between the ultrasonic transducer and the cover layer varying in accordance with the compression;
ultrasonic transmitter(s) are configured to transmit ultrasound signals (transmitted ultrasound signals) towards the cover layer;
the cover layer is configured to reflect a fraction f of ultrasound signals incident thereon (reflected ultrasound signals);
ultrasonic receiver(s) are configured to receive the reflected ultrasound signals;
the signal processor is configured to obtain time-of-flight data indicating time differences between times of transmission of transmitted ultrasound signals by the ultrasonic transmitter(s) and times of receipt of reflected ultrasound signals by the ultrasonic receiver(s); and
the time differences vary in accordance with the ultrasound propagation distance.
2 . The ultrasound time-of-flight sensor module of claim 1 , wherein the signal processor is housed in the ultrasonic transducer device.
3 . The ultrasound time-of-flight sensor module of claim 1 , wherein the fraction f is at least 50%.
4 . The ultrasound time-of-flight sensor module of claim 1 , wherein the elastic member comprises rubber or plastic.
5 . The ultrasound time-of-flight sensor module of claim 1 , wherein the elastic member is more deformable than the cover layer.
6 . The ultrasound time-of-flight sensor module of claim 1 , wherein the cover layer comprises metal.
7 . The ultrasound time-of-flight sensor module of claim 6 , wherein the metal is aluminum.
8 . The ultrasound time-of-flight sensor module of claim 1 , wherein:
the ultrasonic transducer device additionally comprises a force-measuring element;
the signal processor is electronically coupled to the force-measuring element; and
the signal processor is configured to read signals from the force-measuring element.
9 . The ultrasound time-of-flight sensor module of claim 8 , wherein:
the force-measuring element is a piezoelectric force-measuring element; and
the signal processor is configured to read voltage signals from the piezoelectric force-measuring element resulting from mechanical deformation of the piezoelectric force-measuring element.
10 . The ultrasound time-of-flight sensor module of claim 9 , wherein the force-measuring element is a piezoelectric micromechanical force-measuring element (PMFE).
11 . A tactile-sensing system, comprising:
the ultrasound time-of-flight sensor module of claim 1 , configured to be positioned at a tactile edge;
wherein the signal processor is configured to obtain at least one tactile-related data from the ultrasound time-of-flight data when the external object impacts and/or contacts the cover layer.
12 . The tactile-sensing system of claim 11 , wherein the tactile-related data is selected from (1) a material characteristic of the external object and (2) rigidity of the external object.
13 . The tactile-sensing system of claim 11 , wherein the ultrasound time-of-flight sensor module is configured to be mounted to a robot.
14 . The tactile-sensing system of claim 11 , additionally comprising: a force-measuring element;
wherein the signal processor is electronically coupled to the force-measuring element; and
the signal processor is configured to obtain impact data from the force-measuring element.
15 . The tactile-sensing system of claim 14 , wherein:
the force-measuring element is a piezoelectric force-measuring element; and
the signal processor is configured to obtain impact data in accordance with mechanical deformation of the piezoelectric force-measuring element resulting from the impact and/or contact.
16 . The tactile-sensing system of claim 15 , wherein the force-measuring element is a piezoelectric micromechanical force-measuring element (PMFE).
17 . The tactile-sensing system of claim 14 , wherein the impact data is selected from: (1) time-varying impact force, (2) timing of impact, (3) magnitude of impact, (4) frequency of impact, and (5) rigidity of the external object.
18 . A tactile-sensing method, comprising the steps of:
configuring an ultrasound time-of-flight sensor module positioned at a tactile edge, the ultrasound time-of-flight sensor module comprising (1) an ultrasonic transducer device comprising at least one ultrasonic transducer, each ultrasonic transducer being configured as an ultrasonic transmitter and/or an ultrasonic receiver, (2) a cover layer, and (3) an elastic member interposed between the ultrasonic transducer device and the cover layer and mechanically coupled to the cover layer and to the ultrasonic transducer device;
moving the tactile edge towards an external object and/or moving the external object towards the tactile edge such that the external object impacts and/or contacts the cover layer and the elastic member undergoes reversible compression, an ultrasound propagation distance between the ultrasonic transducer and the cover layer varying in accordance with the compression;
transmitting, by the ultrasonic transmitter(s), ultrasound signals (transmitted ultrasound signals) towards the cover layer;
reflecting, by the cover layer, a fraction f of ultrasound signals incident thereon (reflected ultrasound signals);
receiving, by the ultrasonic receiver(s), reflected ultrasound signals;
obtaining, by a signal processor, time-of-flight data at least in part from the reflected ultrasound signals; and
obtaining, by the signal processor, at least one tactile-related data of the external object from the time-of-flight data;
wherein the time-of-flight data indicate time differences between times of transmission of transmitted ultrasound signals by the ultrasonic transmitter(s) and times of receipt of reflected ultrasound signals by the ultrasonic receiver(s); and
the time differences vary in accordance with the ultrasound propagation distance.
19 . The tactile-sensing method of claim 18 , wherein the tactile-related data is selected from (1) a material characteristic of the external object and (2) rigidity of the external object.
20 . The tactile-sensing method of claim 18 , wherein:
configuring an ultrasound time-of-flight sensor module additionally comprises configuring a force-measuring element, the signal processor electronically coupled to the force-measuring element; and
the method additionally comprises:
obtaining, by the signal processor, impact data from the force-measuring element resulting from the impact and/or contact.
21 . The tactile-sensing method of claim 20 , wherein:
the force-measuring element is a piezoelectric force-measuring element; and
obtaining, by the signal processor, impact data from the force-measuring element comprises obtaining impact data in accordance with mechanical deformation of the piezoelectric force-measuring element resulting from the impact and/or contact.
22 . The tactile-sensing system of claim 21 , wherein the force-measuring element is a piezoelectric micromechanical force-measuring element (PMFE).
23 . The tactile-sensing method of claim 20 , wherein the impact data is selected from: (1) time-varying impact force, (2) timing of impact, (3) magnitude of impact, (4) frequency of impact, and (5) rigidity of the external object.