SYSTEMS, DEVICES, AND METHODS FOR A ROBOTIC DIGIT AND DETERMINING MOTIONS AND POSITIONS THEREOF

In an implementation, a position transducer includes a printed circuit board (PCB) and a wiper in sliding contact with the PCB. The PCB includes a first and a second connector pad, and a conductive trace comprising two legs. One leg has an end electrically communicatively coupled to the first connector pad, and the other leg has an end electrically communicatively coupled to the second connector pad. The wiper includes a first blade electrically communicatively coupled to the first leg and a second blade electrically communicatively coupled to the second leg. In operation, an electrical path length of a conductive path between the first and the second connector pad depends, at least in part, on a relative position of the PCB and the wiper. One or more of the position transducers can be used to determine a relative position of actuatable components of a robotic digit.

TECHNICAL FIELD

The present systems, devices, and methods generally relate to robotics, and particularly relate to determining motions and positions of robotic digits.

BACKGROUND

Robots are machines that can assist humans or substitute for humans. Robots can be used in diverse applications including construction, manufacturing, monitoring, exploration, learning, and entertainment. Robots can be used in dangerous or uninhabitable environments, for example.

Some robots require user input, and can be operated by humans. Other robots have a degree of autonomy, and can operate, in at least some situations, without human intervention. Some autonomous robots are designed to mimic human behavior. Autonomous robots can be particularly useful in applications where robots are needed to work for an extended time without operator intervention, to navigate within their operating environment, and/or to adapt to changing circumstances.

Robots can be powered by hydraulic power systems, electric motors, and other power sources. Power can be distributed to a robot's components, e.g., actuators. Actuators can be used to convert energy into movement of the robot.

Robots typically have end effectors. Some end effectors include robotic digits. The end effectors of humanoid robots are referred to in the present application as robotic hands and/or robotic feet. The digits of robotic hands are referred to as robotic fingers and/or robotic thumbs. The digits of robotic feet are referred to as robotic toes.

BRIEF SUMMARY

A position transducer may be summarized as comprising a printed circuit board (PCB), the PCB comprising a first connector pad, a second connector pad, and a conductive trace comprising a first leg and a second leg, the first leg having a first end, the first end electrically communicatively coupled to the first connector pad, and the second leg having a second end, the second end electrically communicatively coupled to the second connector pad; and a wiper in sliding contact with the PCB, the wiper comprising a first blade and a second blade, the first blade electrically communicatively coupled to the first leg of the conductive trace, and the second blade electrically communicatively coupled to the second leg of the conductive trace, wherein, in operation, an electrical path length of a conductive path between the first connector pad and the second connector pad depends, at least in part, on a relative position of the PCB and the wiper.

In some implementations, the first leg of the conductive trace includes a first portion, the first portion which electrically communicatively couples the first connector pad to the first blade, and the second leg of the conductive trace includes a second portion, the second portion which electrically communicatively couples the second connector pad to the second blade, wherein the first connector pad, the first portion of the conductive trace, the first blade, the second blade, the second portion of the conductive trace, and the second connector pad form the conductive path.

In some implementations, at least a portion of the second leg of the conductive trace is substantially parallel with at least a portion of the first leg of the conductive trace.

In some implementations, at least a portion of the first leg of the conductive trace is a first curve and at least a portion of the second leg of the conductive trace is a second curve. The second curve may be substantially parallel to the first curve.

In some implementations, at least one of the first blade and the second blade is sprung to maintain the wiper in sliding contact with the PCB.

In some implementations, the position transducer further comprises at least one spring, wherein the at least one spring urges at least one of the first blade and the second blade towards at least one of the first leg and the second leg of the conductive trace, respectively.

In some implementations, the position transducer further comprises an electrical source electrically communicatively coupled to the first and the second connector pad, a meter electrically communicatively coupled to the first and the second connector pad, the meter which, in operation, determines the electrical path length of the conductive path, and a transmitter which, in operation, transmits the relative position of the PCB and the wiper to a controller.

In some implementations, the meter, in operation, determines the electrical path length of the conductive path based at least in part on an electrical resistance of the conductive path.

In some implementations, the conductive trace is a U-shaped conductive trace.

A robotic digit may be summarized as comprising a first joint, the first joint mechanically coupling a first portion of the robotic digit and a second portion of the robotic digit, and a first position transducer, the first position transducer comprising a first printed circuit board (PCB), the first PCB comprising a first connector pad, a second connector pad, and a first conductive trace comprising a first leg and a second leg, the first leg having a first end, the first end electrically communicatively coupled to the first connector pad, and the second leg having a second end, the second end electrically communicatively coupled to the second connector pad; and a first wiper in sliding contact with the first PCB, the first wiper comprising a first blade and a second blade, the first blade electrically communicatively coupled to the first leg of the first conductive trace, and the second blade electrically communicatively coupled to the second leg of the first conductive trace, wherein, in operation, a first electrical path length of a first conductive path between the first connector pad and the second connector pad depends, at least in part, on a relative position of the first PCB and the first wiper.

In some implementations, the first leg of the first conductive trace includes a first portion, the first portion which electrically communicatively couples the first connector pad to the first blade, and the second leg of the first conductive trace includes a second portion, the second portion which electrically communicatively couples the second connector pad to the second blade, wherein the first connector pad, the first portion of the first conductive trace, the first blade, the second blade, the second portion of the first conductive trace, and the second connector pad form the first conductive path.

In some implementations, at least a portion of the second leg of the first conductive trace is substantially parallel with at least a portion of the first leg of the first conductive trace.

In some implementations, at least a portion of the first leg of the first conductive trace is a first curve and at least a portion of the second leg of the first conductive trace is a second curve. The second curve may be substantially parallel to the first curve.

In some implementations, the robotic digit further comprises at least one spring, wherein the at least one spring urges the first blade towards the first leg of the first conductive trace and the second blade towards the second leg of the first conductive trace.

In some implementations, the robotic digit further comprises an electrical source electrically communicatively coupled to the first and the second connector pad, a meter electrically communicatively coupled to the first and the second connector pad, the meter which, in operation, determines the electrical path length of the first conductive path, and a transmitter which, in operation, transmits the relative position of the first PCB and the first wiper to a controller.

In some implementations, the meter, in operation, determines the electrical path length of the first conductive path based at least in part on an electrical resistance of the first conductive path.

In some implementations, the robotic digit is a robotic finger of a robotic hand of a humanoid robot.

In some implementations, the first joint is a knuckle joint.

In some implementations, the relative position of the first PCB and the first wiper includes an angle defining a pitch rotation of the second portion of the robotic digit relative to the first portion of the robotic digit.

In some implementations, the robotic digit further comprises a second position transducer, the second position transducer comprising a second printed circuit board (PCB), the second PCB comprising a third connector pad, a fourth connector pad, and a second conductive trace comprising a third leg and a fourth leg, the third leg having a third end, the third end electrically communicatively coupled to the third connector pad, and the fourth leg having a fourth end, the fourth end electrically communicatively coupled to the fourth connector pad, and a second wiper in sliding contact with the second PCB, the second wiper comprising a third blade and a fourth blade, the third blade electrically communicatively coupled to the third leg of the second conductive trace, and the fourth blade electrically communicatively coupled to the fourth leg of the second conductive trace, wherein, in operation, a second electrical path length of a second conductive path between the third connector pad and the fourth connector pad depends, at least in part, on a relative position of the second PCB and the second wiper. The relative position of the first PCB and the first wiper, and the relative position of the second PCB and the second wiper, may include a first angle defining a pitch rotation of the second portion of the robotic digit relative to the first portion of the robotic digit, and a second angle defining a yaw rotation of the second portion of the robotic digit relative to the first portion of the robotic digit.

In some implementations, the robotic digit further comprises a second joint, the second joint mechanically coupling a third portion of the robotic digit to the second portion of the robotic digit, and a second position transducer, the second position transducer comprising a second printed circuit board (PCB), the second PCB comprising a third connector pad, a fourth connector pad, and a second conductive trace comprising a third leg and a fourth leg, the third leg having a third end, the third end electrically communicatively coupled to the third connector pad, and the fourth leg having a fourth end, the fourth end electrically communicatively coupled to the fourth connector pad, and a second wiper in sliding contact with the second PCB, the second wiper comprising a third blade and a fourth blade, the third blade electrically communicatively coupled to the third leg of the second conductive trace, and the fourth blade electrically communicatively coupled to the fourth leg of the second conductive trace, wherein, in operation, a second electrical path length of a second conductive path between the third connector pad and the fourth connector pad depends, at least in part, on a relative position of the second PCB and the second wiper. The relative position of the second PCB and the second wiper may include an angle defining a pitch rotation of the third portion of the robotic digit relative to the second portion of the robotic digit. The third leg of the second conductive trace may include a third portion, the third portion which electrically communicatively couples the third connector pad to the third blade, and the fourth leg of the second conductive trace may include a fourth portion, the fourth portion which electrically communicatively couples the fourth connector pad to the fourth blade, wherein the third connector pad, the third portion of the second conductive trace, the third blade, the fourth blade, the fourth portion of the second conductive trace, and the fourth connector pad form the second conductive path.

At least a portion of the second leg of the first conductive trace may be substantially parallel to at least a portion of the first leg of the first conductive trace. At least a portion of the first leg of the first conductive trace may be a first curve and at least a portion of the second leg of the first conductive trace may be a second curve. The second curve may be substantially parallel to the first curve. At least one of the first conductive trace and the second conductive trace may be a U-shaped conductive trace.

In some implementations, the first conductive trace is a U-shaped conductive trace.

A robotic end effector may be summarized as comprising a first robotic digit, the first robotic digit comprising a first joint, the first joint mechanically coupling a first portion of the first robotic digit and a second portion of the first robotic digit, and a first position transducer, the first position transducer comprising a first printed circuit board (PCB), the first PCB comprising a first connector pad, a second connector pad, and a first conductive trace comprising a first leg and a second leg, the first leg having a first end, the first end electrically communicatively coupled to the first connector pad, and the second leg having a second end, the second end electrically communicatively coupled to the second connector pad, and a first wiper in sliding contact with the first PCB, the first wiper comprising a first blade and a second blade, the first blade electrically communicatively coupled to the first leg of the first conductive trace, and the second blade electrically communicatively coupled to the second leg of the first conductive trace, wherein, in operation, a first electrical path length of a first conductive path between the first connector pad and the second connector pad depends, at least in part, on a relative position of the first PCB and the first wiper, and a second robotic digit, the second robotic digit comprising a second joint, the second joint mechanically coupling a first portion of the second robotic digit and a second portion of the second robotic digit, and a second position transducer, the second position transducer comprising a second printed circuit board (PCB), the second PCB comprising a third connector pad, a fourth connector pad, and a second conductive trace comprising a third leg and a fourth leg, the third leg having a third end, the third end electrically communicatively coupled to the third connector pad, and the fourth leg having a fourth end, the fourth end electrically communicatively coupled to the fourth connector pad, and a second wiper in sliding contact with the second PCB, the second wiper comprising a third blade and a fourth blade, the third blade electrically communicatively coupled to the third leg of the second conductive trace, and the fourth blade electrically communicatively coupled to the fourth leg of the second conductive trace, wherein, in operation, a second electrical path length of a second conductive path between the third connector pad and the fourth connector pad depends, at least in part, on a relative position of the second PCB and the second wiper.

In some implementations, the first leg of the first conductive trace includes a first portion, the first portion which electrically communicatively couples the first connector pad to the first blade, and the second leg of the first conductive trace includes a second portion, the second portion which electrically communicatively couples the second connector pad to the second blade, wherein the first connector pad, the first portion of the first conductive trace, the first blade, the second blade, the second portion of the first conductive trace, and the second connector pad form the first conductive path.

In some implementations, at least a portion of the second leg of the first conductive trace is substantially parallel with at least a portion of the first leg of the first conductive trace.

In some implementations, at least a portion of the first leg of the first conductive trace is a first curve and at least a portion of the second leg of the first conductive trace is a second curve. The second curve may substantially parallel to the first curve.

In some implementations, at least one of the first blade and the second blade is sprung to maintain the first wiper in sliding contact with the first PCB.

In some implementations, the robotic end effector further comprises at least one spring, wherein the at least one spring urges at least one of the first blade and the second blade towards at least one of the first leg and the second leg of the first conductive trace, respectively.

In some implementations, the robotic end effector further comprises an electrical source electrically communicatively coupled to the first and the second connector pad, a meter electrically communicatively coupled to the first and the second connector pad, the meter which, in operation, determines the first electrical path length of the first conductive path, and a transmitter which, in operation, transmits the relative position of the first PCB and the first wiper to a controller.

In some implementations, the meter, in operation, determines the first electrical path length of the first conductive path based at least in part on an electrical resistance of the first conductive path.

In some implementations, the first conductive trace is a U-shaped conductive trace.

DETAILED DESCRIPTION

The following description sets forth specific details in order to illustrate and provide an understanding of various implementations and embodiments of the present systems, devices, and methods. A person of skill in the art will appreciate that some of the specific details described herein may be omitted or modified in alternative implementations and embodiments, and that the various implementations and embodiments described herein may be combined with each other and/or with other methods, components, materials, etc. in order to produce further implementations and embodiments.

In some instances, well-known structures and/or processes associated with computer systems and data processing have not been shown or provided in detail in order to avoid unnecessarily complicating or obscuring the descriptions of the implementations and embodiments.

Unless the specific context requires otherwise, throughout this specification and the appended claims the term “comprise” and variations thereof, such as “comprises” and “comprising,” are used in an open, inclusive sense to mean “including, but not limited to.”

Unless the specific context requires otherwise, throughout this specification and the appended claims the singular forms “a,” “an,” and “the” include plural referents. For example, reference to “an embodiment” and “the embodiment” include “embodiments” and “the embodiments,” respectively, and reference to “an implementation” and “the implementation” include “implementations” and “the implementations,” respectively. Similarly, the term “or” is generally employed in its broadest sense to mean “and/or” unless the specific context clearly dictates otherwise.

The headings and Abstract of the Disclosure are provided for convenience only and are not intended, and should not be construed, to interpret the scope or meaning of the present systems, devices, and methods.

A robot may include one or more sensors. Some sensors can be used to sense the external environment, for example, to see or to hear objects in the external environment, or to sense a physical property of the external environment such as temperature or pressure. Some sensors can be used to sense information about the robot itself, for example, where it is, how fast it is moving, where is one part of the robot relative to another, and so forth.

A robot may include one or more actuators, and physically actuatable components that can be moved under the control of the robot, a pilot, and/or a control system. Actuators may be linear or rotary. Some actuators are hydraulic, and convert movement of a piston into linear or rotary motion. Some actuators are pneumatic, and use compressed air to produce movement. Some actuators are electric, and convert AC or DC electric energy into linear or rotary motion.

It can be advantageous for a robot to be able to sense where its actuatable components are in relation to each other and to other parts of the robot. Knowing the relative position of actuatable components can be useful in controlling parts of the robot, e.g., in controlling end effectors and their digits.

The technology described below includes a position transducer integrated with elements of an end effector, e.g., integrated with a knuckle joint in a robotic digit. Multiple position transducers can be integrated with a) a single knuckle joint, b) multiple joints in a single robotic digit, and/or c) multiple digits of an end effector. Data from multiple integrated position transducers can be used to determine relative positions of elements of the end effector, including pitch and yaw orientations of phalanges on either side of a knuckle joint.

The technology described below includes space-efficient ways to determine more precisely the relative positions of phalanges in a robotic digit. The relative positions can be transmitted to a controller in the robot or to an external controller. The technology can advantageously support the control and performance of a robot's dexterous hands, for example, in situations where a robot is tasked with grasping objects in its external environment that have different form factors.

FIG.1Ais a schematic drawing of an example implementation of a position transducer100, in accordance with the present systems, devices, and methods. Position transducer100includes a printed circuit board (PCB)102, and a wiper104.

PCB102includes a non-conductive substrate106. Substrate106may include FR-2 (a phenolic paper or a phenolic cotton paper, impregnated with a phenol formaldehyde resin) and/or FR-4 (a woven fiberglass cloth impregnated with an epoxy resin), for example.

Wiper104includes blades118and120, a body122, and an attachment124. Wiper104is in sliding contact with PCB102, the contact being between blade118and conductive leg114of U-shaped conductive trace112, and between blade120and conductive leg116of U-shaped conductive trace112. Blades118and120, and body122may, for example, include a conductive metal or metal alloy. Blades118and120, and body122may, for example, include copper, copper nickel, or a noble metal alloy.

Connector pad108, conductive leg114, blade118, wiper body122, blade120, conductive leg116, and connector pad110form an electrically conductive path between a connection electrically communicatively coupled to connector pad108and a connection electrically communicatively coupled to connector pad110. The connection electrically communicatively coupled to connector pad108may be an input signal. The connection electrically communicatively coupled to connector pad110may be an output signal. An electric current may travel from connector pad108, along conductive leg114, up blade118, across body122, down blade120, and along conductive leg116to connector pad110.

At least a portion of each of conductive legs114and116may be a respective curve. In at least a portion of conductive leg116, the curve of conductive leg116may be at least substantially parallel to at least a portion of the curve of conductive leg114. The curves of conductive legs114and116may be selected to be substantially parallel to one another so that blades118and120remain in contact with conductive legs114and116, respectively, over a range of motion of wiper104relative to PCB102. Blades118and120can remain in contact with conductive legs114and116over the range of motion of wiper104relative to PCB102provided conductive legs114and116maintain a separation that matches a separation between blades118and120. Typically, conductive legs114and166are substantially parallel to one another, and remain in contact with blades118and120, respectively, if a difference in a normal distance between the curves of conductive legs114and116is less than 10% of the average normal distance between the curves of conductive legs114and116.

Conductive legs114and116may be separated from one another by a portion of substrate106. In one implementation, conductive legs114and116are separated from one another by a portion of substrate106having a width approximately equal to a width of conductive leg114and/or conductive leg116.

In some implementations, blades118and120are urged against conductive legs114and116, respectively. Blades118and120may be sprung so as to urge blades118and120against conductive legs114and116. The urging may be caused by a spring (not shown inFIG.1A).

Position transducer100is an example of a potentiometer. In operation of position transducer100, PCB102and wiper104slide against one another, and the electrical path length of the electrically conductive path described above depends, at least in part, on a relative position of PCB102and wiper104. For example, when the relative position of PCB102and wiper104is such that blades118and120contact conductive legs114and116closer to connector pads108and110, the electrical path is shorter.

As described below with reference toFIGS.3A,3B,4A,4B,5,6,7A,7B, and7C, position transducer100can be used to determine relative positions of two phalanges at a knuckle joint, for example. Signals from one or more instances of position transducer100, suitably placed on a robotic digit, can be used to determine a bending of the digit at one or more knuckle joints. When two phalanges pivot at a knuckle joint, blades118and120slide along conductive legs114and116, respectively, while maintaining electrical contact. The change in position of contact points between blades118and120, and conductive legs114and116, respectively, can cause a change in the electrical path length between connector pads108and110. The change in the electrical path length can cause a commensurate change in electrical resistance. In this way, the relative positions of the two phalanges can be encoded in different resistance values.

In some implementations, the signal is a 3 V or 5 V signal. In some implementations, an electrical path traversing U-shaped connective trace112has a resistance of about 19 kΩ. In some implementations, an electrical path between connector pads108and110, when the robotic digit is in a resting position, has a resistance of about 16 kΩ.

FIG.1Bis a schematic drawing of printed circuit board (PCB)102of position transducer100ofFIG.1A, in accordance with the present systems, devices, and method. PCB102includes substrate106, connector pads108and110, and U-shaped conductive trace112. Conductive trace112includes conductive legs114and116.

Position transducer ofFIG.1A(including PCB102ofFIGS.1A and1B, and wiper104ofFIG.1A) is an example of a geometry that can be accommodated in a metacarpophalangeal (MCP) joint of a humanoid robotic digit.

A position determination system that includes position transducer100ofFIG.1A, in accordance with the present systems, devices, and methods, also includes an electrical source, a meter, and a transmitter. The electrical source provides an electrical signal to position transducer100. The meter determines an electrical path length in position transducer100. The transmitter transmits the electrical path length and/or positional data (e.g., a relative position of PCB102and wiper104of position transducer100ofFIG.1A) to a controller. The controller may include one or more processors.

FIG.2Ais a schematic drawing of another example implementation of a position transducer, in accordance with the present systems, devices, and methods. Position transducer200includes a printed circuit board (PCB)202, and a wiper204. Position transducer200(including PCB202and wiper204) is an example of a geometry that can be accommodated in a proximal interphalangeal (PIP) joint of a humanoid robotic digit.

The elements of position transducer200are similar to the elements of position transducer100ofFIG.1. The elements of position transducer100ofFIG.1were described in detail with reference toFIG.1. Position transducers100and200differ in shape and may differ in size.

As described above with reference to position transducer100ofFIG.1A, position transducer200can be used to determine relative positions of two phalanges at a knuckle joint, for example. Relative motion of PCB202and wiper204can cause a change in an electrical path length between connector pads208and210, and the change in the electrical path length can cause a commensurate change in electrical resistance.

FIG.2Bis a schematic drawing of PCB202of position transducer200ofFIG.2A, in accordance with the present systems, devices, and method.

FIG.3Ais a schematic drawing of an example implementation of a robotic digit300shown from above, in accordance with the present systems, devices, and methods. Digit300is analogous to a human finger, therefore digit300is described below in terms that can be used to describe the anatomy of a humanoid digit (e.g., a thumb or a finger).

Digit300includes a position transducer316on a left-hand side of MCP302, and a position transducer318on a left-hand side of PIP304. In some implementations, digit300includes a position transducer (not shown inFIG.3A) at DIP306.

In some implementations, position transducers (e.g., position transducer100ofFIG.1A) are integrated with an elbow, a knee, a pivot joint, or another suitable joint.

Position transducer316is operable to determine a relative orientation of metacarpal308and proximal phalange310. The relative orientation of metacarpal308and proximal phalange310may include an angle of pitch (up/down) between metacarpal308and proximal phalange310.

Similarly, position transducer318is operable to determine a relative orientation of proximal phalange310and middle phalange312. The relative orientation of proximal phalange310and middle phalange312may include an angle of pitch between proximal phalange310and middle phalange312.

Each of position transducers316and318may send a respective signal to a controller (not shown inFIG.3B) where each signal includes the respective relative orientation described above. Each signal may be part of a respective feedback loop used to control a movement of digit300.

FIG.3Bis a schematic drawing of robotic digit300ofFIG.3Ashown from below, in accordance with the present systems, devices, and methods. As well as the elements described above with reference toFIG.3A, digit300also includes a position transducer320on a right-hand side of MCP302, and a position transducer322on a right-hand side of PIP304.

Each of MCP joint302and PIP joint304of digit300can be actuated by a respective two actuators. Each actuator may be an actuation piston of a hydraulic system, for example. Operation of the two actuators at each of MCP joint302and PIP joint304may be coordinated to control a respective movement of digit300.

Movement of digit300caused by the two actuators at MCP joint302can include a controllable change in pitch (up/down) and/or a controllable change in yaw (side-to-side) between metacarpal308and proximal phalange310. The change in pitch can be caused by operating the two actuators in concert. The change in yaw can be caused by operating the two actuators differentially, or asymmetrically.

Similarly, movement of digit300caused by the two actuators at PIP joint304can include a controllable change in pitch (up/down) and/or a controllable change in yaw (side-to-side) between proximal phalange310and middle phalange312. The change in pitch can be caused by operating the two actuators in concert. The change in yaw can be caused by operating the two actuators differentially, or asymmetrically.

Signals from position transducers316and320can be used to determine pitch and yaw data for MCP joint302. In a particular operational scenario where signals from position transducers316and320are indicative of the same position or the same relative position, it can be inferred that the angle of yaw between metacarpal308and proximal phalange310is zero. In an example implementation, each of position transducers316and320is a respective position transducer100ofFIG.1Athat includes a respective PCB102and wiper104. At zero yaw, the respective PCB102and wiper104are in the same relative position in each of position transducers316and320.

Similarly, signals from position transducers318and322can be used to determine pitch and yaw data for PIP joint304. As above, where signals from position transducers318and322are indicative of the same position or the same relative position, it can be inferred that the angle of yaw between proximal phalange310and middle phalange312is zero. Also as above, in an example implementation, each of position transducers318and322is a respective position transducer100ofFIG.1Athat includes a respective PCB102and wiper104. At zero yaw, the respective PCB102and wiper104are in the same relative position in each of position transducers318and322.

In some implementations, only one position transducer is integrated with PIP joint304, for example position transducer318. A signal from position transducer318can be used to determine pitch data for PIP joint304.

In some implementations, there is pitch motion at PIP joint304but there is no yaw motion at PIP joint304, i.e., there is no yaw motion between proximal phalange310and middle phalange312. In these implementations, only one position transducer is used, i.e., a position transducer operable to determine pitch data. In some of these implementations, there are both pitch and yaw motions at MCP joint302, i.e., between metacarpal308and proximal phalange310. In these implementations, there are two position transducers located at MCP joint302(e.g., position transducers316and320), and only one position transducer located at PIP joint304(e.g., position transducer318).

FIG.4Ais a schematic drawing of a portion400aof the underside of robotic digit300ofFIGS.3A and3Bshowing position transducer320on the right-hand side of metacarpophalangeal (MCP) joint302, in accordance with the present systems, devices, and methods. Portion400aincludes a PCB402aand a wiper404a. PCB402aincludes a substrate406a, connector pads408aand410a, and conductive traces412aand414a. Wiper404aincludes blades416aand418awhich are slidably in contact with conductive traces412aand414a, respectively.

FIG.4Bis a schematic drawing of a portion400bof the underside of robotic digit300ofFIGS.3A and3Bshowing position transducer320on the right-hand side and position transducer316the left-hand side of MCP joint302, in accordance with the present systems, devices, and methods. Position transducer316on the left-hand side includes a PCB402band a wiper404b. The elements of PCB402band wiper404bare similar to the elements of PCB402aand wiper404adescribed above. PCB402bincludes a substrate406b, connector pads408band410b, and conductive traces412band414b. Wiper404bincludes blades416band418bwhich are slidably in contact with conductive traces412band414b, respectively.

FIG.6is a schematic drawing of a portion600of proximal phalange310and proximal interphalangeal (PIP) joint304of robotic digit300ofFIGS.3A and3Bshowing position transducer322on the right-hand side of the PIP joint304, in accordance with the present systems, devices, and methods. Portion600includes proximal phalange310, a PCB602and a wiper604. PCB602includes a substrate606, connector pads608and610, and conductive traces612and614. Wiper604includes blades616and618which are slidably in contact with conductive traces612and614, respectively.

FIG.7Ais a schematic drawing of an example implementation of a robotic digit700, similar to robotic digit300ofFIGS.3A and3B, where robotic digit700is pointing downwards, in accordance with the present systems, devices, and methods.

Robotic digit700includes a metacarpal702, an MCP joint704, a proximal phalange706, a PIP joint708, a middle phalange710, a DIP joint712, and a distal phalange. In the configuration shown inFIG.7A, proximal, middle, and distal phalanges706,710, and714, respectively, are at a downwards pitch angle relative to metacarpal702.

Robotic digit700includes position transducers716aand716bat MCP joint704. Robotic digit700also includes a position transducer718at PIP joint708. Position transducers716aand716bcan be used to determine a pitch angle between metacarpal702and proximal phalange706. The pitch angle can be determined from a respective electrical path length and commensurate electrical resistance of the path in each of position transducers716aand716b. When robotic digit700moves to a new pitch angle, the respective electrical path length and commensurate electrical resistance of the path in each of position transducers716aand716bchange to new values indicative of the new pitch.

FIG.7Bis a schematic drawing of robotic digit700ofFIG.7Acurled inwards, in accordance with the present systems, devices, and methods. In the configuration shown inFIG.7B, proximal phalange706is at a downwards pitch angle relative to metacarpal702, middle phalange710is at a downwards pitch angle relative to proximal phalange706, and distal phalange714is at a downwards pitch angle relative to middle phalange710.

As described above with reference to position transducers716aand716b, position transducer718can be used to determine a pitch angle between proximal phalange706and middle phalange710. The pitch angle can be determined from a respective electrical path length and commensurate electrical resistance of the path in position transducer718. When robotic digit700moves to a new pitch angle, the respective electrical path length and commensurate electrical resistance of the path in position transducer718change to new values indicative of the new pitch.

FIG.7Cis a schematic drawing of robotic digit700ofFIGS.7A and7Bpointing sideways, in accordance with the present systems, devices, and methods. In the configuration shown inFIG.7C, proximal, middle, and distal phalanges706,710, and714, respectively, are at a right-leaning yaw angle relative to metacarpal702.

In addition to determining pitch data, position transducers716aand716bcan be used to determine a yaw angle between metacarpal702and proximal phalange706. The yaw angle can be determined from a respective electrical path length and commensurate electrical resistance of the path in each of position transducers716aand716b. The yaw angle can be determined at least in part from a relative resistance (or a relative change in resistance) in the respective electrical paths in each of position transducers716aand716b. When robotic digit700moves to a new yaw angle, the respective electrical path length and commensurate electrical resistance of the path in each of position transducers716aand716bchange to new values indicative of the new yaw.

In some implementations, each of position transducers716aand716bis calibrated to provide a respective baseline electrical resistance R01and R02determined at a known fixed pitch and/or yaw. In some implementations, the known fixed pitch and/or yaw is zero pitch and/or zero yaw.

After robotic digit700has moved to a new position, each of position transducers716aand716bcan be determined to have an electrical resistance denoted by R1and R2, respectively. A respective change in resistance from the baseline can be determined for each of position transducers716aand716bas follows:

In some implementations, a pitch angle of proximal phalange706relative to metacarpal702of robotic digit700can be determined, at least in part, from an average of ΔR1and ΔR2. In some implementations, the pitch angle is proportional to the average of ΔR1and ΔR2. In other implementations, the pitch angle is non-linearly related to the average of ΔR1and ΔR2, and can be determined, for example, from a reference model or a look-up table for the pitch angle. A positive value of the average of ΔR1and ΔR2may indicate a pitch downwards, and a negative value of the average of ΔR1and ΔR2may indicate a pitch upwards, or vice versa.

Similarly, in some implementations, a yaw angle of proximal phalange706relative to metacarpal702of robotic digit700can be determined, at least in part, from a difference between ΔR1and ΔR2, i.e., (ΔR1−ΔR2). In some implementations, the yaw angle is proportional to (ΔR1−ΔR2). In other implementations, the yaw angle is non-linearly related to (ΔR1−ΔR2), and can be determined, for example, from a reference model or a look-up table for the yaw. A positive value of (ΔR1−ΔR2) may indicate a yaw to the right, and a negative value of (ΔR1−ΔR2) may indicate a yaw to the left, or vice versa.

Calibration of position transducers716aand716bmay be performed before and/or after installation of each of position transducers716aand716bin robotic digit700. Calibration may include determining an electrical resistance at multiple different pitch and yaw angles and/or at multiple different relative positions of a wiper and a conductive trace (for example, wiper104and conductive trace112of position transducer100ofFIG.1A).

Other suitable methods may be used to extract the pitch and yaw angles from signals output by position transducers716aand716b, alone or in combination.

FIG.8is a schematic drawing of an example implementation of a portion900of a hydraulic system in a forearm802, wrist804, and hand806of a robot (e.g., robot900ofFIG.9), in accordance with the present systems, devices, and methods. Hand806includes a robotic digit808.

Forearm802includes a set of valves810which is integrated with forearm802. Valves810include valve810-1. (Only one valve is separately labeled for clarity of illustration.) Valves810may include pressure valves and exhaust valves. Valves810may include electrohydraulic servo valves, and may be operated by a controller (not shown inFIG.8).

Digit808includes an actuation piston812integrated with digit808. Actuation piston812is hydraulically coupled to valves810via a pressure hose814and an exhaust hose816.

In some implementations, digit808may include multiple actuators. Some actuators may be used to control movement of joints in digit808. For example, actuators may be used to control movement of one or more knuckle joints.

Digit808may include one or more knuckle joints. For example, digit808may include one or more of a metacarpophalangeal (MCP) joint, a proximal interphalangeal (PIP) joint, and a distal interphalangeal (DIP) joint. Digit808may include one or more position transducers described above (for example, position transducer100ofFIG.1).

FIG.9is a schematic drawing of an example implementation of a robot900, in accordance with the present systems, devices, and methods. Robot900comprises a base902and a humanoid upper body904. Base902comprises a pelvic region906and two legs908aand908b(collectively referred to as legs908). Only the upper portion of legs908is shown inFIG.9. In other example implementations, base902may comprise a stand and (optionally) one or more wheels.

Upper body904comprises a torso910, a head912, right-side arm914aand a left-side arm914b(collectively referred to as arms914), and a right hand916aand a left hand916b(collectively referred to as hands916). Arms914of robot900are also referred to in the present application as robotic arms. Arms914of robot900are humanoid arms. In other implementations, arms914have a form factor that is different from a form factor of a humanoid arm.

Hands916are also referred to in the present application as end effectors. In other implementations, hands916have a form factor that is different from a form factor of a humanoid hand. Each of hands916comprises one or more digits, for example, digit918of hand916a. Digits may include fingers, thumbs, or similar structures of the hand or end effector.

Robot900is a hydraulically-powered robot. In other implementations, robot900has alternative or additional power systems. In some implementations, base902and/or torso910of upper body904house a hydraulic control system, for example. In some implementations, components of the hydraulic control system may alternatively be located outside the robot, e.g., on a wheeled unit that rolls with the robot as it moves around, or in a fixed station to which the robot is tethered.

The hydraulic control system of robot900comprises a hydraulic pump922, a reservoir924, and an accumulator926, housed in arm914a. Hose928provides a hydraulic coupling between accumulator926and a pressure valve930of the hydraulic control system. Hose932provides a hydraulic coupling between an exhaust valve934of the hydraulic control system and reservoir924.

Pressure valve930is hydraulically coupled to an actuation piston936by a hose938. Actuation piston936is hydraulically coupled to exhaust valve934by a hose940. Hoses928and938, and pressure valve930, provide a forward path to actuation piston936. Hoses932and940, and exhaust valve934provide a return path to actuation piston936. Pressure valve930and exhaust valve934can control actuation piston936, and can cause actuation piston936to move, which can cause a corresponding motion of at least a portion of hand916a, for example, digit918.

Each of hands916may have more than one degree of freedom (DOF). In some implementations, each hand has up to eighteen (18) DOFs. Each DOF can be driven by a respective actuation piston (for example, actuation piston936). For clarity of illustration, only one actuation piston is shown inFIG.9. Each actuation piston may be located in hands916.

In some implementations, digit918may include multiple actuators. Some actuators may be used to control movement of joints in digit918. For example, actuators may be used to control movement of one or more knuckle joints.

Digit918may include one or more knuckle joints. For example, digit918may include one or more of a metacarpophalangeal (MCP) joint, a proximal interphalangeal (PIP) joint, and a distal interphalangeal (DIP) joint. Digit918may include one or more position transducers described above (for example, position transducer100ofFIG.1). The position transducers may provide positional data for robot900to be self-aware of a position of one or more components of digit918with respect to each other, and/or to provide control of digit918.

The various implementations described herein may include, or be combined with, any or all of the systems, devices, and methods described in U.S. patent application Ser. No. 17/491,577, U.S. patent application Ser. No. 17/491,583, U.S. patent application Ser. No. 17/491,586, and U.S. Provisional Patent Application Ser. No. 63/191,732, all of which are incorporated herein by reference in their entirety.

Throughout this specification and the appended claims, infinitive verb forms are often used. Examples include, without limitation: “to provide,” “to control,” and the like. Unless the specific context requires otherwise, such infinitive verb forms are used in an open, inclusive sense, that is as “to, at least, provide,” “to, at least, control,” and so on.

This specification, including the drawings and the abstract, is not intended to be an exhaustive or limiting description of all implementations and embodiments of the present systems, devices, and methods. A person of skill in the art will appreciate that the various descriptions and drawings provided may be modified without departing from the spirit and scope of the disclosure. In particular, the teachings herein are not intended to be limited by or to the illustrative examples of robotic systems and hydraulic circuits provided.

The claims of the disclosure are below. This disclosure is intended to support, enable, and illustrate the claims but is not intended to limit the scope of the claims to any specific implementations or embodiments. In general, the claims should be construed to include all possible implementations and embodiments along with the full scope of equivalents to which such claims are entitled.