Patent Publication Number: US-2023150135-A1

Title: Robots and methods for protecting fragile components thereof

Description:
TECHNICAL FIELD 
     The present robots and methods generally relate to fall events and particularly relate to protecting fragile members from damage during fall events. 
     BACKGROUND 
     Robots can be prone to falling. For example, robots can trip, lose balance, have control problems, or any number of issues that can result in the robot not being stable and falling towards the ground or other objects in an unintended way. Further, robots can be equipped with fragile members. For example, in order to interact with objects in the world, robots can have complicated, expensive, or easily damaged or breakable end effectors (e.g. hands). As another example, robots can have other complicated, expensive, or easily damaged or breakable features, such as aesthetic coatings, covers, masks, etc. A fall event can break, damage, scratch, chip, or otherwise harm such fragile members. 
     BRIEF SUMMARY 
     According to a broad aspect, the present disclosure describes a robot comprising: a body; a fragile member; at least one processor; at least one sensor communicatively coupled to the at least one processor; at least one non-transitory processor-readable storage medium communicatively coupled to the at least one processor, the at least one non-transitory processor-readable storage medium storing processor-executable instructions which, when executed by the at least one processor, cause the robot to: detect, by the at least one processor, a fall event of the body based on sensor data from the at least one sensor; in response to detecting the fall event, actuate at least one member of the robot to protect the fragile member. 
     The processor-executable instructions which, when executed by the at least one processor, cause the robot to actuate at least one member of the robot to protect the fragile member may cause the robot to: actuate the fragile member to a defensive configuration which protects the fragile member from damage during the fall event. The defensive configuration may be a contracted configuration. The fragile member may include an end effector comprising a plurality of finger-shaped members coupled to a palm-shaped member; and the defensive configuration may be a fist-shaped configuration. The fragile member may include a plurality of gripper-members; and the defensive configuration may be a configuration in which the gripper-members are closed together. 
     The robot may include at least one actuatable member; and the processor-executable instructions which, when executed by the at least one processor, cause the robot to actuate at least one member of the robot to protect the fragile member may cause the robot to: actuate the at least one actuatable member to a protective configuration which protects the fragile member from damage during the fall event. The at least one actuatable member may comprise at least one support member coupled to the body and stored in a contracted configuration; and the processor-executable instructions which, when executed by the at least one processor, cause the robot to actuate the at least one actuatable member to a protective configuration may cause the at least one actuatable member to extend from the body to an extended configuration which braces the body during the fall event. The at least one actuatable member may comprise at least one support member; and the processor-executable instructions which, when executed by the at least one processor, cause the robot to actuate the at least one actuatable member to a protective configuration may cause the at least one actuatable member to extend from a stowed configuration to a support configuration which braces the fragile member during the fall event. The fragile member may include a plurality of fragile members; the at least one actuatable member may include a plurality of actuatable members; and the processor-executable instructions which, when executed by the at least one processor, cause the robot to actuate the at least one actuatable member to a protective configuration which protects the fragile member from damage during the fall event may cause the robot to: actuate each actuatable member of the plurality of actuatable members to a respective protective configuration which protects a respective fragile member of the plurality of fragile members from damage during the fall event. 
     The robot may include at least one actuatable member; and the processor-executable instructions which, when executed by the at least one processor, cause the robot to actuate at least one member of the robot to protect the fragile member may cause the robot to: actuate the fragile member to a defensive configuration which protects the fragile member from damage during the fall event; and actuate the at least one actuatable member to a protective configuration which protects the fragile member from damage during the fall event. The defensive configuration may be a contracted configuration, and the protective configuration may be an extended configuration. The fragile member may comprise an end effector coupled to the body by the at least one actuatable member; the processor-executable instructions which, when executed by the at least one processor, cause the robot to actuate the fragile member to a defensive configuration may cause the robot to actuate the fragile member to move towards the body; and the processor-executable instructions which, when executed by the at least one processor, cause the robot to actuate the at least one actuatable member to a protective configuration may cause the robot to actuate the at least one actuatable member to extend away from the body. The fragile member may comprise a hand-shaped end effector; the at least one actuatable member may comprise an arm member including an elbow portion; the hand-shaped end effector may be coupled to the body by the arm member; the processor-executable instructions which, when executed by the at least one processor, cause the robot to actuate the fragile member to a defensive configuration may cause the robot to actuate the hand-shaped end effector to move towards the body; and the processor-executable instructions which, when executed by the at least one processor, cause the robot to actuate the at least one actuatable member to a protective configuration may cause the robot to actuate the arm member to extend the elbow portion away from the body. The hand-shaped member may include two hand-shaped members; and the at least one arm member may include two arm members. The robot may further comprise at least one support structure coupled to the at least one actuatable member which protects the at least one actuatable member from damage during the fall event. The at least one support structure may be selected from a group of structures consisting of: at least one pad; at least one pedestal; and at least one spring. The at least one actuatable member may comprise an arm member having an elbow portion; and the at least one support structure may comprise at least one elbow pad positioned at or proximate the elbow portion. The processor-executable instructions, when executed by the at least one processor, may further cause the robot to, in response to detecting the fall event: actuate the elbow pad to cover the elbow portion. The support structure may be actuatable between a stowed configuration in which the support structure is stowed, and a support configuration in which the support structure supports the at least one actuatable member; and the processor-executable instructions, when executed by the at least one processor, may further cause the robot to, in response to detecting the fall event, actuate the at least one support structure from the stowed configuration to the support configuration. 
     The at least one sensor may comprise at least one sensor selected from a group of sensors consisting of: an accelerometer; a gyroscope; an inertial measurement unit; a visual sensor; a LIDAR sensor; an audio sensor; and a tactile sensor. 
     The robot may further comprise two actuatable leg members. The two actuatable leg members may be actuatable to move the robot by bipedal motion. The at least one non-transitory processor-readable storage medium may store further instructions which, when executed by the at least one processor, cause the robot to: move by bipedal motion of the two actuatable leg members. 
     According to another broad aspect, the present disclosure describes a method comprising: detecting, by at least one processor of a robot, a fall event of a body of the robot based on sensor data from at least one sensor of the robot communicatively coupled to the at least one processor; in response to detecting the fall event, actuating at least one member of the robot to protect a fragile member of the robot. 
     Actuating at least one member of the robot to protect the fragile member may comprise: actuating the fragile member to a defensive configuration which protects the fragile member from damage during the fall event. Actuating the fragile member to a defensive configuration may comprise actuating the fragile member to a contracted configuration. The fragile member may include an end effector comprising a plurality of finger-shaped members coupled to a palm-shaped member; and actuating the fragile member to a defensive configuration may comprise actuating the finger-shaped members to move towards the palm-shaped member to a fist-shaped configuration. The fragile member may include a plurality of gripper-members; and actuating the fragile member to a defensive configuration may comprise actuating the gripper members to close together. 
     The robot may include at least one actuatable member; and actuating at least one member of the robot to protect the fragile member may comprise: actuating the at least one actuatable member to a protective configuration which protects the fragile member from damage during the fall event. The at least one actuatable member may comprise at least one support member coupled to the body and stored in a contracted configuration; and actuating the at least one actuatable member to a protective configuration may comprise: extending the at least one actuatable member from the body to an extended configuration which braces the body during the fall event. The at least one actuatable member may comprise at least one support member; and actuating the at least one actuatable member to a protective configuration may comprise extending the at least one support member from a stowed configuration to a support configuration which braces the fragile member during the fall event. The fragile member may include a plurality of fragile members; the at least one actuatable member may include a plurality of actuatable members; and actuating the at least one actuatable member to a protective configuration which protects the fragile member from damage during the fall event may comprise: actuating each actuatable member of the plurality of actuatable members to a respective protective configuration which protects a respective fragile member of the plurality of fragile members from damage during the fall event. 
     The robot may include at least one actuatable member; and actuating at least one member of the robot to protect the fragile member may comprise: actuating the fragile member to a defensive configuration which protects the fragile member from damage during the fall event; and actuating the at least one actuatable member to a protective configuration which protects the fragile member from damage during the fall event. Actuating the fragile member to a defensive configuration may comprise actuating the fragile member to a contracted configuration, and actuating the at least one actuatable member to a protective configuration may comprise actuating the at least one actuatable member to an extended configuration. The fragile member may comprise an end effector coupled to the body by the at least one actuatable member; actuating the fragile member to a defensive configuration may comprise actuating the fragile member to move towards the body; and actuating the at least one actuatable member to a protective configuration may comprise actuating the at least one actuatable member to extend away from the body. The fragile member may comprise a hand-shaped end effector; the at least one actuatable member may comprise an arm member including an elbow portion; the hand-shaped end effector may be coupled to the body by the arm member; actuating the fragile member to a defensive configuration may comprise actuating the hand-shaped end effector to move towards the body; and actuating the at least one actuatable member to a protective configuration may comprise actuating the arm member to extend the elbow portion away from the body. The fragile member may comprise two hand-shaped end effectors; the at least one actuatable member may comprise two arm members, each arm member including a respective elbow portion; each hand-shaped end effector may be coupled to the body by a respective one of the arm members; actuating the fragile member to a defensive configuration may comprise actuating each of the hand-shaped end effectors to move towards the body; and actuating the at least one actuatable member to a protective configuration may comprise actuating each of the arm members to extend each respective elbow portion away from the body. The robot may include at least one support structure coupled to the at least one actuatable member, the support structure may be actuatable between a stowed configuration in which the support structure is stowed, and a support configuration in which the support structure supports the at least one actuatable member; and the method may further comprise, in response to detecting the fall event, actuating the at least one support structure from the stowed configuration to the support configuration. The at least one support structure may comprise at least one pad positioned at or proximate the at least one actuatable member; and the method may further comprise, in response to detecting the fall event, actuating the pad to cover the at least one actuatable member. The at least one actuatable member may comprise an arm member having an elbow portion; the at least one support structure may comprise at least one elbow pad positioned at or proximate the elbow portion; and actuating the at least one support structure from the stowed configuration to the support configuration may comprise actuating the elbow pad to cover the elbow portion. The at least one support structure may comprise at least one pedestal positioned at the at least one actuatable member; and actuating the at least one support structure from the stowed configuration to the support configuration may comprise actuating the pedestal to extend from the at least one actuatable member. The at least one support structure may comprise at least one spring positioned at the at least one actuatable member; and actuating the at least one support structure from the stowed configuration to the support configuration may comprise actuating the spring to extend from the at least one actuatable member. 
     The method may further comprise collecting, by the at least one sensor, sensor data selected from a group of data consisting of: acceleration data; orientation data; angular velocity data; velocity data; inertial data; visual data; LIDAR data; audio data; and tactile data. The method may further comprise moving the robot in bipedal motion, by two actuatable leg members of the robot. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The various elements and acts depicted in the drawings are provided for illustrative purposes to support the detailed description. Unless the specific context requires otherwise, the sizes, shapes, and relative positions of the illustrated elements and acts are not necessarily shown to scale and are not necessarily intended to convey any information or limitation. In general, identical reference numbers are used to identify similar elements or acts. 
         FIG.  1    is a front view of a robot which may experience a fall event. 
         FIG.  2    is a flowchart diagram of an exemplary method for operating a robot. 
         FIGS.  3 A,  3 B, and  3 C  are side views of an exemplary end effector coupled to a member of a robot. 
         FIGS.  4 A and  4 B  are side views of an exemplary head, neck, and torso of a robot. 
         FIGS.  5 A and  5 B  are side views of another exemplary end effector coupled to a member of a robot.  FIG.  5 C  is an isometric view of the end effector shown in  FIGS.  5 A and  5 B . 
         FIGS.  6 A and  6 B  are front views of a robot having an actuatable support member. 
         FIGS.  7 A and  7 B  are side views of another robot having an actuatable support member. 
         FIGS.  8 A and  8 B  are side views of an exemplary end effector and a corresponding support member. 
         FIGS.  9 A and  9 B  are side views of an exemplary head, neck, torso and corresponding support members of a robot. 
         FIGS.  10 A,  10 B, and  10 C  are side views of a robot which experiences a fall event. 
         FIGS.  10 D and  10 E  are top views of a robot which experiences a fall event. 
         FIGS.  11 A and  11 B  illustrate an actuatable member having support structure to protect the actuatable member during a fall event. 
         FIGS.  12 A and  12 B  illustrate another actuatable member having support structure to protect the actuatable member during a fall event. 
         FIGS.  13 A and  13 B  illustrate yet another actuatable member having support structure to protect the actuatable member during a fall event. 
     
    
    
     DETAILED DESCRIPTION 
     The following description sets forth specific details in order to illustrate and provide an understanding of the various implementations and embodiments of the present robots 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 robots and methods. 
     The various embodiments described herein provide robots and methods for protecting fragile members from damage during fall events. Generally, “fragile member” refers to a member which is easily damaged or broken (relative to other members of a robot). However, in the context of this disclosure, “fragile member” can also refer to a member which is problematic if broken or damaged, even if said fragile member is not more easily damaged or broken relative to certain other members of a robot. This could be for example because the member could be expensive, difficult or time consuming to manufacture, difficult or time consuming to replace/repair, or usability of the robot could be significantly impaired due to the damage, as non-limiting examples. Alternative terms for “fragile member” could include “susceptible member”, “vulnerable member”, “breakable member”, “precious member”, “important member”, or any other appropriate term which conveys the relative importance or susceptibility to damage of the member. Several exemplary fragile members are discussed throughout this disclosure. 
       FIG.  1    is a front view of an exemplary robot  100  in accordance with one implementation. In the illustrated example, robot  100  includes a body  101  that is designed to approximate human anatomy, including a torso  110  coupled to a plurality of members including head  111  (via neck  112 ), right arm  113  (in turn coupled to end effector  114 ), right leg  115 , left arm  116  (in turn coupled to end effector  117 ), and left leg  118 , which approximate anatomical features. More or fewer anatomical features could be included as appropriate for a given application. Further, how closely a robot approximates human anatomy can also be selected as appropriate for a given application. In some applications, a robot body may only approximate a portion of human anatomy. As non-limiting examples, only an arm of human anatomy, only a head or face of human anatomy; or only a leg of human anatomy could be approximated. In some applications, a robot may not approximate human anatomy at all. 
     Members  110 ,  111 ,  112 ,  113 ,  114 ,  115 ,  116 ,  117 , and/or  118  can be actuatable relative to other components. Actuators, motors, or other movement devices can couple together actuatable members. Driving said actuators, motors, or other movement driving mechanism causes actuation of the actuatable members. For example, rigid limbs in a humanoid robot can be coupled by motorized joints, where actuation of the rigid limbs is achieved by driving movement in the motorized joints. In some implementations, such actuators, motors, or other movement driving mechanisms can be included in corresponding actuatable members. It is not required that each of components  110 ,  111 ,  112 ,  113 ,  114 ,  115 ,  116 ,  117 , and/or  118  be actuatable; some of these components can be non-actuatable. As one example, head  111  could be rigidly coupled to torso  110  by a rigid neck  112 . It is also possible that any or all of components  110 ,  111 ,  112 ,  113 ,  114 ,  115 ,  116 ,  117 , and/or  118  be actuatable. As one example, head  111  could be actuated by actuation of neck  112 . Further any of the members can include sub-members, and said sub-members can be actuatable. As one example, head  111  could include sub-members such as eyebrows, eyes, lips, or any other appropriate sub-members, which can be actuated (e.g. to emulate human emotions). 
     Robot  100  is also illustrated as including sensors  120 ,  122 ,  124 ,  126 , and  128 , which collect sensor data. In the example, sensors  120  and  122  are image sensors (e.g. cameras) that capture visual data. LIDAR sensors which capture LIDAR data could also be used. Sensors  124  and  126  are audio sensors (e.g. microphones) that capture audio data. Sensor  128  can include at least one motion or orientation sensor, such as an accelerometer, a gyroscope, an inertial measurement unit, a compass, or a magnetometer. Such sensors could capture, for example, acceleration data, orientation data, angular velocity data, velocity data, inertial data, or any other appropriate type of data. Although not illustrated, robot  100  could also include a tactile sensor, which captures tactile data. Many types of sensors are illustrated and discussed with reference to the example of  FIG.  1   , but more or fewer sensor types could be included as appropriate for a given application. As examples, only one of the exemplary sensor types could be included, a subset of the exemplary sensor types could be included, all of the exemplary sensor types could be included, or even more sensor types than those discussed could be included. Further, any appropriate number of sensors of a given sensor type could be included. As examples, only one sensor of a given type could be included, or a plurality of sensors of a given type could be included. Any combination of sensor types and number of sensors of each type could be included as appropriate for a given application. Further, although sensors  120  and  122  are shown as approximating human eyes, and sensors  124  and  126  are shown as approximating human ears, sensors  120 ,  122 ,  124 , and  126  could be positioned in any appropriate locations. 
     Robot  100  is also illustrated as including at least one processor  132 , communicatively coupled to at least one non-transitory processor-readable storage medium  134 . The at least one processor  132  can control actuation of members  110 ,  111 ,  112 ,  113 ,  114 ,  115 ,  116 ,  117 , and  118 ; can receive and process data from sensors  120 ,  122 ,  124 ,  126  and  128 ; and can perform fall detection as discussed later with reference to  FIG.  2   . The at least one non-transitory processor-readable storage medium  134  can have processor-executable instructions stored thereon, which when executed by the at least one processor  132  can cause robot  100  to perform any of the methods discussed herein (e.g. method  200  in  FIG.  2   ). Further, the at least one non-transitory processor-readable storage medium  134  can store sensor data or any other data as appropriate for a given application. The at least one processor  132  and the at least one processor-readable storage medium  134  together can be considered as components of a “robot controller”  130 , in that they control operation of robot  100  in some capacity. While the at least one processor  132  and the at least one processor-readable storage medium  134  can perform all of the respective functions described in this paragraph, this is not necessarily the case, and the “robot controller”  130  can be remote from body  101 , or further include components that are remote from body  101 . 
     In emulating human anatomy, it can be helpful or desirable for a robot to not only emulate physical features of human anatomy, but to also emulate how a human moves. For example, bipedal motion (a form of locomotion where movement occurs by means of two legs) can be emulated. This makes a robot (such as robot  100 ) resemble a human more closely aesthetically, and also better enables the robot to conduct itself in human environments. In particular, human environments are typically designed and constructed in ways that are conducive to human anatomy (such as in ways that are suited to bipedal motion). Examples of this include stairs or ladders, as non-limiting examples, which are challenging for other forms of locomotion like wheels. Additionally, even if not specifically designed by and constructed for humans, it can be desirable for a robot to be operable in environments which humans operate in, including flat terrain, hilly terrain, rocky terrain, mountainous terrain, or terrain with obstacles, as non-limiting examples—all of which are traversable by bipedal walking. 
     To this end, robot  100  as shown in  FIG.  1    includes two actuatable leg members: right leg member  115  and left leg member  118 . Leg members  115  and  118  are actuatable to move robot  100  by bipedal motion. That is, leg members  115  and  118  can alternately apply force to a ground surface to move robot  100  in a desired direction. In some implementations, control of leg members  115  and  118  can be provided by a tele-operation system, where an operator equips motion sensors to themselves (such as leg motion sensors, through additional sensors could also be equipped, such as a body motion sensing suit), and performs bipedal motion. The bipedal motion is sensed by the motion sensors and emulated by the robot  100 . In other implementations (such as after an control system of robot  100  has been trained in bipedal motion), the at least one non-transitory processor-readable storage medium  134  of robot  100  stores instructions, at least one control paradigm, or other form of control data, which when executed by the at least one processor  132  causes robot  100  to move by bipedal motion of the actuatable leg members  115  and  118 . Further, methods of operation of a robot such as robot  100  can comprise moving the robot in bipedal motion, by two actuatable leg members of the robot (actuatable leg members  115  and  118  in robot  100 ). 
     However, bipedal motion is difficult to emulate, and can increase the likelihood that a robot will lose balance and experience a fall event. Conventionally, when a bipedal human experiences a fall event, the human will extend their hands and try to catch themselves by falling on their hands. In implementations of the present systems, devices, and methods in which the robot&#39;s hands are fragile members, it is desirable to avoid this instinctive “catch/absorb a fall with the hands” behavior. Thus, while it can be advantageous to enable a robot to emulate human function and behavior by designing and operating a robot to achieve bipedal walking, in accordance with the present systems, devices, and methods a bipedal robot may be purposefully designed and operated away from the conventional “catch/absorb a fall with the hands” behavior that is inherent in other bipedal systems (such as humans) and after which a bipedal robot may otherwise be modeled. Instead, a bipedal robot may be designed and operated to protect its hands (and/or other fragile member(s)) when it falls by, for example, curling the hands into a protected configuration, directing its elbows (or support structure) towards the fall, and catching/absorbing the fall with its elbows (or support structure) as described in more detail herein. 
       FIG.  2    is a flowchart diagram showing an exemplary method  200  of operation of a robot in accordance with the present systems, devices, and methods. Method  200  as illustrated includes acts  202  and  204 , though those of skill in the art will appreciate that in alternative implementations certain acts may be omitted and/or additional acts may be added. In some implementations, method  200  can be performed by robot  100  discussed with reference to  FIG.  1   . Discussion of method  200  below references elements of robot  100  for convenience, but method  200  can be performed by any appropriate robot having at least one processor, a body, at least one sensor, and a fragile member. Further, at least one processor-readable storage medium (such as the at least one non-transitory processor-readable storage medium  134 ) can store processor-executable instructions that, when executed by at the at least one processor (such as the at least one processor  132 ), cause the robot to perform the method  200 . 
     At act  202 , the at least one processor  132  detects a fall event of body  101  of robot  100 , based on sensor data from at least one sensor communicatively coupled to the at least one processor  132  (e.g. any of sensors  120 ,  122 ,  124 ,  126 , or  128 ). As one example, if the at least one sensor includes a visual sensor, the at least one processor  132  could detect a fall event based on a sudden shift in captured visual data (from the visual sensor experiencing movement of the fall event). As another example, if the sensor includes a LIDAR sensor, the at least one processor  132  could detect a fall event based on a sudden shift in captured LIDAR data (from the LIDAR sensor experiencing movement of the fall event). As another example, if the at least one sensor includes an accelerometer, the at least one processor  132  could detect a fall event based on acceleration of body  101  (e.g. sudden acceleration of body  101  downwards). As yet another example, if the at least one sensor includes a gyroscope, compass, or magnetometer, the at least one processor  132  could detect a change in orientation of the body  101  (e.g. body  101  tipping over). As yet another example, if the at least one sensor includes an inertial measurement unit, the at least one processor  132  could detect an inertial change of body  101 , such as acceleration or angular acceleration (such as sudden acceleration or rotation of body  101 ). As yet another example, if the at least one sensor includes an audio sensor, the at least one processor  132  could detect a sound of air on a microphone, or a sound of clattering robot parts (sounds of body  101  falling). As yet another example, if the at least one sensor includes a velocity sensor, the at least one processor can detect sudden changes in velocity (body  101  experiencing motion of the fall event). As yet another example, if the at least one sensor includes a tactile sensor, the at least one processor  132  could detect impact against body  101  (e.g. from at least one member of body  101  colliding against each other or against another object during the fall event). In some implementations, sensor data from a plurality of sensors can be captured and processed, such that different types of sensor data can be synthesized or processed, to accurately detect fall events and minimize occurrence of false positive detections or false negative errors. 
     At act  204 , in response to detecting the fall event, at least one member of the robot is actuated to protect a fragile member of the robot. In some implementations, the fragile member itself can be actuated to a defensive configuration to protect the fragile member from damage during the fall event, as discussed later with reference to  FIGS.  3 A,  3 B,  3 C,  4 A,  4 B,  5 A,  5 B, and  5 C , as examples. In other implementations, an actuatable member is actuated to a protective configuration to protect the fragile member from damage during the fall event, as discussed later with reference to  FIGS.  6 A,  6 B,  7 A,  7 B,  8 A,  8 B,  9 A,  9 B,  10 B,  10 C, and  10 D , as examples. In some implementations, the fragile member itself is actuated to a defensive configuration and an actuatable member is actuated to a protective configuration to protect the fragile member from damage during the fall event, as discussed with reference to  FIGS.  10 B,  10 D, and  10 E , as examples. 
     As mentioned above, in some implementations, actuating at least one member of the robot to protect the fragile member as in act  204  of method  200  in  FIG.  2    comprises actuating the fragile member to a defensive configuration to protect the fragile member from damage during the fall event. In some exemplary implementations, the fragile member can be actuated to a contracted or closed configuration. Several examples are discussed below with reference to  FIGS.  3 A,  3 B,  3 C,  4 A,  4 B,  5 A,  5 B, and  5 C . 
       FIGS.  3 A,  3 B, and  3 C  are side views of an exemplary end effector  310  coupled to a member  320  of a robot. Member  320  could be, for example, an arm of robot  100  in  FIG.  1   . In the illustrated example, end effector  310  comprises a pair of grippers  312  and  314 , which are operable to open and close relative to each other, to grip or release objects therebetween. In other implementations, additional grippers could be included, as appropriate. Due to their complicated mechanical nature, and relatively small components (compared to other parts of a robot), end effectors can be more easily broken or damaged than other components of a robot, and can be more expensive to manufacture and replace than other components of a robot. In this sense, end effectors can be “fragile members” or a robot. In the example, gripper members  312  and  314  are thinner (made of less material) than member  320 , and can include delicate actuation hardware. Thus, in the example of  FIGS.  3 A,  3 B, and  3 C , end effector  310  is a “fragile member”. 
       FIG.  3 A  illustrates end effector  310  in an open configuration, with gripper members  312  and  314  spaced apart from each other, to receive an object therebetween.  FIG.  3 B  illustrates end effector  310  in a closed configuration, with gripper members  312  and  314  touching each other. While the closed configuration is useful to grip objects, the closed configuration is also useful as a defensive configuration to protect end effector  310  from damage during a fall event. In particular, actuating the fragile member to a defensive configuration as in act  204  of method  200  in  FIG.  2    may comprise actuating gripper members  312  and  314  to close together. In this way, the strength of individual gripper members  312  and  314  reinforce each other, such that end effector  310  is more robust against impact that may occur during a fall event. The closed configuration of  FIG.  3 B  can also be called a contracted configuration, in that gripper members  312  and  314  are “contracted” inward relative to each other. 
       FIG.  3 C  illustrates another contracted configuration, where end effector  310  is contracted into a recess in member  320 . In this way, end effector  310  is protected by member  320  during a fall event. In  FIG.  3 C , end effector  310  is shown as being partially contracted in member  320  (i.e. gripper members  312  and  314  are shown as partially protruding from member  320 ), but in some implementations, end effector  310  can be fully contracted into member  320 , such that end effector  310  is fully protected by member  320 . 
       FIGS.  4 A and  4 B  are side views of torso  110 , head  111 , and neck  112  as discussed with reference to robot  100  in  FIG.  1   . In the example illustrated in  FIG.  4 A and  4 B , head  111  has a face  411 . Face  411  could comprise, as non-limiting examples: complex mechanical components like eyes, eyebrows, lips, or other facial features which approximate human anatomy; sensors like visual sensors, or other sensor types; aesthetic design features like masks or surface textures; or any other appropriate elements. Due to the presence of such components or elements, face  411  can be a “fragile member”, in that elements of the face  411  can be easily broken or damaged, or expensive or difficult to replace. Even in cases whether elements of face  411  themselves aren&#39;t easily broken, even minor damage to face  411  can have dramatic consequences, since the face is an important aesthetic element, which robots can use to emulate human anatomy. Even small scratches or dents in face  411  can be problematic. 
       FIG.  4 A  illustrates head  111  in an erect configuration (i.e. held straight up, similar to in human anatomy).  FIG.  4 B  illustrates head  111  in bent-over configuration. The bent-over configuration of  FIG.  4 B  can be valuable as a defensive configuration, in that face  411  is less likely to be subjected to impact during a fall event if head  111  is in the bent-over configuration. As such, actuating the fragile member to a defensive configuration as in act  204  of method  200  in  FIG.  2    may comprise actuating head  111  to bend forward (toward torso  110 ). The bent-over configuration of  FIG.  4 B  can also be called a contracted configuration, in that the head  111  is contracted towards the torso  110 . 
       FIGS.  5 A,  5 B, and  5 C  illustrate an exemplary end effector  510  coupled to a member  520  of a robot. Member  520  could be, for example, an arm of robot  100  in  FIG.  1   . In the illustrated example, end effector  510  is hand-shaped, to grip or release objects similar to how a human hand would. In the illustrated example, end effector  510  includes finger-shaped members  540 ,  550 ,  560 ,  570 , and  580 . Although five finger-shaped members are illustrated, any number of finger-shaped members could be included as appropriate for a given application. Each of finger-shaped members  540 ,  550 ,  560 ,  570 , and  580  are coupled to a palm-shaped member  530 . Palm-shaped member  530  serves as a common member to which the finger-shaped members are coupled. In the example, each of finger-shaped members  540 ,  550 ,  560 ,  570 , and  580  are actuatable relative to the palm-shaped member  530 . In particular, member  540  is actuatable relative to member  530  at joint  541 ; member  550  is actuatable relative to member  530  at joint  551 ; and member  580  is actuatable relative to member  530  at joint  581 . Members  560  and  570  are similarly actuatable relative to member  530  at respective joints, but these joints are not labelled to avoid clutter. Finger-shaped members can also include joints at which sub-members of a given finger-shaped member are actuatable. In the illustrated example, finger-shaped member  540  includes sub-member  542  and sub-member  544 , actuatable relative to each other about joint  543 . Similarly, finger-shaped member  550  includes sub-members  552 ,  555 , and  558 , actuatable relative to each other about joints  554  and  557 . Similarly, finger-shaped member  580  includes sub-members  582 ,  584 , and  586 , actuatable relative to each other about joints  583  and  585 . Finger-shaped members  560  and  570  include similar sub-members and joints, but they are not labelled to avoid clutter. A finger-shaped member can include any number of sub-members and joints, as appropriate for a given application. 
     Due to their complicated mechanical nature, and relatively small components (compared to other parts of a robot), end effectors can be more easily broken or damaged than other components of a robot, and can be more expensive to manufacture and replace than other components of a robot. For example, joints  541 ,  543 ,  551 ,  554 ,  557 ,  581 ,  583 , and  585  may be designed for motion of finger-shaped members and sub-members towards the palm-shaped member  530  (as illustrated in  FIG.  5 B  discussed below), but may not be designed for extensive motion in the opposite direction. Motion in an unintended direction, such as may be caused by force due to a fall event, may break or damage finger-shaped members, joints, or sub-members. As another example, finger-shaped members, sub-members, and joints may be made thinner (made of less material) than member  520 , and can include delicate actuation hardware. In this sense, any components of an end effector, such as the finger shaped members, sub-members, or joints discussed with reference to  FIGS.  5 A,  5 B, and  5 C  can be “fragile members” or a robot. Additionally,  FIGS.  5 A,  5 B, and  5 C  illustrate a plurality of optional sensor pads  531 ,  545 ,  546 ,  553 ,  556 , and  559 , and similar sensor pads on finger-shaped members  560  and  570  which are not labelled to avoid clutter. Finger-shaped member  580  is illustrated without sensor pads thereon, which is indicative that in some implementations a hand-shaped member may be only partially covered by sensor pads (although full cover by sensor pads is possible in other implementations). Such sensor pads can collect sensor data, such as tactile data or temperature data. Such sensor pads can also be prone to breaking or damage during a fall event, and thus can also be considered as “fragile members” of a robot. 
       FIG.  5 A  is a front-view which illustrates end effector  510  in an open configuration, with finger-shaped members  540 ,  550 ,  560 ,  570 , and  580  extended from palm-shaped member  530 , to receive an object.  FIG.  5 B  is a front view which illustrates end effector  510  in a closed configuration, with finger-shaped members  540 ,  550 ,  560 ,  570 , and  580  closed into palm-shaped member  530 .  FIG.  5 C  is an isometric view which illustrates end effector  510  in the closed configuration as in  FIG.  5 B . Each of the sub-members and sensor pads are not labelled in  FIGS.  5 B and  5 C  to avoid clutter. While the closed configuration is useful to grip objects, the closed configuration is also useful as a defensive configuration to protect end effector  510  from damage during a fall event. In particular, actuating the fragile member to a defensive configuration as in act  204  of method  200  in  FIG.  2    may comprise actuating finger-shaped members  540 ,  550 ,  560 ,  570 , and  580  to close toward palm-shaped member  530  in the closed configuration. In this way, the strength of individual finger-shaped members  540 ,  550 ,  560 ,  570 , and  580  reinforce each other, such that end effector  510  is more robust against impact that may occur during a fall event. Further, finger-shaped members  540 ,  550 ,  560 ,  570 , and  580  are also in a position where it is less likely that joints will be forced to bend in an unintended direction. The closed configuration of  FIG.  5 B  can also be called a contracted configuration, in that finger-shaped members  540 ,  550 ,  560 ,  570 , and  580  are “contracted” inward relative to each other. The closed configuration can also be referred to as a fist-shaped configuration, due to resemblance to a human fist. 
     Further, the closed configuration of  FIGS.  5 B and  5 C  can also be considered as a protective configuration. In particular, in the closed configuration, finger-shaped members  540 ,  550 ,  560 ,  570 , and  580  at least partially protect sensor pads  531 ,  545 ,  546 ,  553 ,  556 ,  559 , and other unlabeled sensor pads from impact during a fall event. 
     As mentioned above, in some implementations, the robot comprises an actuatable member (in addition to the fragile member), and actuating at least one member of the robot to protect the fragile member as in act  204  of method  200  in  FIG.  2    comprises actuating the actuatable member to a protective configuration which protects the fragile member from damage during the fall event. Several examples are discussed below with reference to  FIGS.  6 A,  6 B,  7 A,  7 B,  8 A,  8 B,  9 A, and  9 B . 
       FIGS.  6 A and  6 B  are front views of robot  100  as discussed with reference to  FIG.  1   . Not all features of robot  100  as illustrated in  FIG.  1    are labelled in  FIGS.  6 A and  6 B , to avoid clutter. Nonetheless, the description of robot  100  with reference to  FIG.  1    is fully applicable to  FIGS.  6 A and  6 B . Further, in  FIGS.  6 A and  6 B , robot  100  includes an actuatable support member  615  coupled to right leg  115 , and an actuatable support member  618  coupled to left leg  118 . Support members  615  and  618  can each be in a contracted configuration as shown in  FIG.  6 A . In  FIG.  6 A , robot  100  is shown as standing on surface  620 . In the example of  FIG.  6 B , robot  100  experiences a fall event. In response to the fall event, actuating the at least one actuatable member (support member  615 ) to a protective configuration comprises extending support member  615  from the body of robot  100  (from leg  115 ) to an extended configuration which braces the body of robot  100  against surface  620 . This can prevent robot  100  from falling over, or at least redirect the fall of robot  100 , so as to protect a fragile member or fragile members of robot  100 . 
     In the example of  FIG.  6 B , support member  615  is shown as extending away from leg  115 , and having an extension member  615   a  extending therefrom. However, the illustrated structure of support member  615  is merely exemplary, and any appropriate structure could be implementations as appropriate for a given application. As one example, a support member may only extend from the body of robot  100  and not include extension member  615   a.  As another example, a support member could include even more extension members, so as to increase surface area with which the support member braces the body of robot  100 . 
     The contracted configuration of support member  615  discussed above and shown in  FIG.  6 A  can also be referred to as a stowed configuration or a compact configuration, as examples. The extended configuration of support member  615  discussed above and shown in  FIG.  6 B  can also be referred to as a support configuration or brace configuration, as examples. Further, description of support member  615  is fully applicable to support member  618 . Support member  615  could be coupled to an exterior of leg  115 , or could be positioned within a recess in leg  115  when in the contracted configuration. Similarly, support member  618  could be coupled to an exterior of leg  118 , or could be positioned within a recess in leg  118  when in the contracted configuration. In some implementations, actuation of support member  615  or  618  could be selectively performed based on a direction which robot  100  falls during a fall event. In the example of  FIG.  6 B , robot  100  falls to the robot&#39;s right, and support member  615  extends to the right to support robot  100 . In a scenario where robot  100  falls to the robot&#39;s left, support member  618  could extend to the left to support robot  100 . Support members  615  and  618  could also be designed to extend forward and/or backward, to support robot  100  during forward falls and backwards falls. 
       FIGS.  7 A and  7 B  are side views of robot  100  as discussed with reference to  FIG.  1   . Not all features of robot  100  as illustrated in  FIG.  1    are labelled in  FIGS.  7 A and  7 B , to avoid clutter. Nonetheless, the description of robot  100  with reference to  FIG.  1    is fully applicable to  FIGS.  7 A and  7 B . Further, in  FIGS.  7 A and  7 B , robot  100  includes an actuatable support member  710  coupled to torso  110 . Support member  710  can be in a contracted configuration as shown in  FIG.  7 A . In  FIG.  7 A , robot  100  is shown as standing on a surface  720 . In the example of  FIG.  7 B , robot  100  experiences a fall event. In response to the fall event, actuating the at least one actuatable member (support member  710 ) to a protective configuration comprises extending support member  710  from the body of robot  100  (from torso  110 ) to an extended configuration which braces the body of robot  100  against surface  720 . This can prevent robot  100  from falling over, or at least redirect the fall of robot  100 , so as to protect a fragile member or fragile members of robot  100 . In the example, such fragile members could include at least one end effector (such as an end effector coupled to arm  116 ) or face  411  (similarly to as described with reference to  FIGS.  4 A and  4 B ). 
     In the example of  FIG.  7 B , support member  710  is shown as extending away from torso  110 , and having an extension member  710   a  extending therefrom. However, the illustrated structure of support member  710  is merely exemplary, and any appropriate structure could be implemented as appropriate for a given application. As one example, a support member may only extend from the body of robot  100  and not include extension member  710   a.  As another example, a support member could include even more extension members, so as to increase surface area with which the support member braces the body of robot  100 . 
     The contracted configuration of support member  710  discussed above and shown in  FIG.  7 A  can also be referred to as a stowed configuration or a compact configuration, as examples. The extended configuration of support member  710  discussed above and shown in  FIG.  7 B  can also be referred to as a support configuration or brace configuration, as examples. Support member  710  could be coupled to an exterior of torso  110 , or could be positioned within a recess in torso  110  when in the contracted configuration. Additional support members could be included as needed to brace the robot  100  during fall events of different directions. 
       FIGS.  8 A and  8 B  are side views of an exemplary end effector  310  coupled to a member  820  of a robot. End effector  310  as illustrated is similar to as described with reference to  FIGS.  3 A,  3 B, and  3 C , and is illustrated as including gripper members  312  and  314 . Member  820  as illustrated is similar to member  320  discussed with reference to  FIGS.  3 A,  3 B , and  3 C, and can be for example an arm of a robot. One difference between member  820  in  FIGS.  8 A and  8 B , and member  320  in  FIGS.  3 A,  3 B, and  3 C , is that member  820  has a support member  822  coupled thereto. Support member  822  is actuatable relative to member  820 . In  FIG.  8 A , support member  822  is shown in a contracted configuration, where support member  822  is positioned so as not to encumber end effector  310  (in the example, at least partially covering member  820 , as indicated by the dashed lines in  FIG.  8 A ). In  FIG.  8 B , support member  822  is shown in an extended configuration, where support member  822  covers end effector  310  (as indicated by the dashed lines in  FIG.  8 B ). The extended configuration of  FIG.  8 B  is useful as a protective configuration, to protect end effector  310  (a fragile member) from damage during a fall event. The contracted configuration of support member  822  discussed above can also be referred to as a stowed configuration or a compact configuration, as examples. The extended configuration of support member  822  can also be referred to as a support configuration or brace configuration, as examples.  FIGS.  8 A and  8 B  illustrate an exemplary implementation where a support member in a protective configuration protects a fragile member by covering said fragile member.  FIG.  8 B  illustrates support member  822  as completely covering end effector  310 , but in some implementations support member  822  may only partially cover send effector  310 . 
     Although  FIGS.  8 A and  8 B  illustrate support member  822  as protecting end effector  310 , support member  822  could protect any fragile member of a robot, as appropriate for a given application. As one example, support member  822  could protect a hand-shaped end effector, such as end effector  510  discussed above with reference to  FIGS.  5 A,  5 B, and  5 C . As another example, support member  822  could be positioned to protect a head member, such as head  111  discussed with reference to  FIG.  1    above. The stated examples are non-limiting, and a support member such as support member  822  could be positioned to protect any appropriate fragile member as appropriate for a given application. 
       FIGS.  9 A and  9 B  are side-views of torso  110 , head  111 , and neck  112  as discussed with reference to robot  100  in  FIG.  1   . In the example, neck  112  is a fragile member, which can include for example complex mechanical structures or data pathways. Torso  110  has at least support members  914  and  916  coupled thereto. In  FIG.  9 A , support members  914  and  916  are shown in contracted configurations, where support members  914  and  916  are positioned so as not to encumber neck  112 . In  FIG.  9 B , support members  914  and  916  are shown in extended configurations, where support members  914  and  916  brace neck  112  to prevent unwanted movement. The extended configurations of  FIG.  9 B  are useful as a protective configuration, to protect neck  112  (a fragile member) from damage during a fall event. For example, if the robot were to fall and impact head  111  against an object, this could result in strong forces being applied to neck  112 ; support members  914  and  916  reinforce neck  112  against such forces and thereby protect neck  112  from damage during the fall event. The contracted configurations of support members  914  and  916  discussed above can also be referred to as stowed configurations or compact configurations, as examples. The extended configurations of support members  914  and  916  can also be referred to as support configurations or brace configurations, as examples.  FIGS.  9 A and  9 B  illustrate an exemplary implementation where a support member in a protective configuration protects a fragile member by providing structural reinforcement to said fragile member, without necessarily covering said fragile member. 
     Although  FIGS.  9 A and  9 B  illustrate support members  914  and  916  as protecting neck  112 , support members  914  and  916  (or more or fewer support members) could protect any fragile member of a robot, as appropriate for a given application. As one example, a support member could protect an end effector, such as end effectors  310  or  510  discussed above with reference to  FIGS.  3 A,  3 B,  3 C,  5 A,  5 B , or  5 C, by extending to brace said end effector. In particular, a support member could extend along a wrist-joint of an end effector to reinforce the wrist joint, without necessarily covering the entire wrist joint. The stated examples are non-limiting, and support members such as support members  914  and  916  could be positioned to protect any appropriate fragile member as appropriate for a given application. 
       FIGS.  10 A,  10 B,  10 C,  10 D, and  10 E  illustrate examples of actuating at least one actuatable member to protect at least one fragile member, with reference to robot  100  described with reference to  FIG.  1   . Unless context dictates otherwise, discussion of  FIG.  1    is applicable to  FIGS.  10 A,  10 B,  10 C,  10 D, and  10 E . Not all components labelled in  FIG.  1    are labelled in  FIGS.  10 A,  10 B,  10 C,  10 D, and  10 E  to avoid clutter. 
       FIG.  10 A  is a side view of robot  100 . Robot  100  as illustrated includes arm member  116 , which includes elbow portion  116   e  (which is an actuatable joint). Arm member  116  is actuatably coupled to torso  110  at one end, and to end effector  117  at another end.  FIGS.  10 A  also shows robot  100  as including face  411  as described above with reference to  FIGS.  4 A and  4 B . In  FIG.  10 A , robot  100  is standing on surface  1010 . 
       FIG.  10 B  is a side view of robot  100  after or during a fall event. In response to detecting the fall event (as in act  202  of method  200  discussed above with reference to  FIG.  2    and other Figures), arm member  116  is actuated to a protective configuration which protects at least one fragile member of robot  100  during the fall event. In the example of  FIG.  10 B , elbow portion  116   e  of arm member  116  is actuated to extend away from torso  110 . In this way, elbow portion  116   e  contacts surface  1010  instead of end effector  117  or face  411 . An elbow joint (such as elbow portion  116   e ) can be made of more material (e.g. made thicker), or can be made simpler, or can be made more cheaply, compared to end-effector components (e.g. fingers or sensor pads) or face components (e.g. actuatable facial features, delicate masks). Consequently, damage to elbow portion  116   e  can be less problematic than damage to end effector  117  and face  411 . In some implementations, support structures can be installed to protect the protective actuatable member (arm member  116  and elbow portion  116   e  in the illustrated example), as discussed in more detail later with reference to  FIGS.  11 A,  11 B,  12 A,  12 B,  13 A, and  13 C . 
       FIG.  10 B  illustrates that an actuatable member which is actuated to a protective configuration does not have to be a dedicated protective member. That is, outside of fall events, arm member  116  serves the purpose of moving end effector  117 , to better enable robot  100  to interact with the world. During a fall event, arm member  116  acts a protective member (i.e. an actuatable member which is actuated to a protective configuration). Utilizing members for multiple purposes like this advantageously can reduce bulk and weight of a robot compared to using dedicated protective members. 
     In addition to actuating an actuatable member to a protective configuration, a fragile member can be actuated to a defensive configuration to protect the fragile member. That is, compound actuation can occur to provide better protection. In the example of  FIG.  10 B , arm member  116  is extended away from torso  110  to a protective configuration as discussed above, and end effector  117  is actuated to a defensive configuration. In particular, end effector  117  is actuated to a defensive configuration, which in the illustrated example includes actuating end effector  117  to a contracted configuration where end effector  117  is moved inwards towards the body of robot  100  (towards torso  110 ). The illustrated defensive configuration is merely one exemplary defensive configuration, and any other defensive configuration could be utilized as appropriate for a given application. As examples, any the defensive configurations discussed with reference to  FIGS.  3 A,  3 B,  3 C,  4 A,  4 B,  5 A,  5 B, and  5 C  could be implemented. Further, any appropriate combination of defensive configurations could be implemented together. As an example, end effector  117  can be actuated to a contracted configuration towards the body of robot  100 , the end effector  117  can be actuated to a closed configuration (such as in  FIGS.  3 B,  5 B , or  5 C), and end effector  117  can be actuated to contract into a support member (such as in  FIG.  3 C ). This combination is merely exemplary, and any other appropriate combination of defensive configurations could be implemented. 
       FIG.  10 C  is a side view of robot  100  after or during a fall event, which is similar to  FIG.  10 B . Unless context dictates otherwise, discussion of  FIG.  10 B  is applicable to  FIG.  10 C . 
     One difference between  FIG.  10 C  and  FIG.  10 B  is that in  FIG.  10 C , end effector  117  is not actuated to a defensive configuration to protect itself. That is, in  FIG.  10 C , end effector  117  is not actuated to a contracted configuration where end effector  117  is moved towards the body of robot  100 . This may result in undesired damage to end effector  117 , but may bring other advantages. In the example of  FIG.  10 C , end effector  117  is positioned in a protective configuration, in front of face  411 , to protect face  411  from damage during the fall event. This could be useful if for example face  411  is more fragile or more valuable than end effector  117 , and thus is more important to protect than end effector  117 . In some implementations, during a fall event, act  202  of method  200  in  FIG.  2    may include not only detecting a fall event, but characterizing, by at least one processor of the robot, the fall event. For example, the at least one processor could detect a direction of fall of the robot, and predict objects with which robot  100  may collide during the fall event, and which members of robot  100  may collide with such objects. Act  204  of method  200  in  FIG.  2    could then include and actuating at least one actuatable member of the robot  100  in an optimal manner which minimizes or eliminates damage to at least one fragile member of the robot  100 . With reference to the example of  FIG.  10 C , the at least one processor  132  of robot  100  may determine that face  411  is likely to take significant damage during the fall event, whereas end effector  117  may be unlikely to take damage during the fall event. In such a scenario, end effector  117  can be actuated to a protective configuration which protects face  411 , as shown in  FIG.  10 C . Analysis of damage to members can be performed based on an expected position of such members if they are actuated. In the example of  FIG.  10 C , the at least one processor  132  can determine the likelihood or extent of damage which end effector is likely to suffer during the fall event if end effector  117  is actuated to the position shown in  FIG.  10 C . 
       FIGS.  10 D and  10 E  are partial top views of robot  100  (top with reference to the upright orientation of robot  100  shown in  FIG.  1   ), after or during a fall event. Head  111  is not illustrated in  FIGS.  10 D and  10 E  to reduce clutter.  FIGS.  10 D and  10 E  are similar to  FIGS.  10 B and  10 C , and discussion of  FIGS.  10 B and  10 C  is applicable to  FIGS.  10 D and  10 E  unless context dictates otherwise. One difference between  FIGS.  10 D and  10 E , compared to  FIGS.  10 B and  10 C , is that  FIGS.  10 D and  10 E  illustrate two arm members: arm member  113  and arm member  116 . Description of arm member  116  with reference to  FIGS.  10 B and  10 C  is applicable to  FIGS.  10 D and  10 E . Arm member  113  is similar to arm member  116 : arm member  113  includes an elbow portion  113   e  (a joint), is coupled to torso  110  at a first end, and is coupled to an end effector  114  at a second end opposite the first end. During a fall event, arm member  113  is actuated to a protective configuration, where elbow portion  113   e  is extended away from torso  110  to protect end effector  114  from damage during the fall event.  FIGS.  10 D and  10 E  illustrate that a fragile member of a robot can include a plurality of fragile members (end effector  114  and end effector  117  in the examples of  FIGS.  10 D and  10 E ), and the at least one actuatable member can include a plurality of actuatable members (arm member  113  and arm member  116  in the examples of  FIGS.  10 D and  10 E ). Actuating the at least one actuatable member to a protective configuration as in act  204  of method  200  in  FIG.  2    can thus comprise actuating each member of the plurality of actuatable members to a respective protective configuration which protects a respective fragile member of the plurality of fragile members from damage during the fall event. 
     It is possible for a single actuatable member of a plurality of actuatable members to be actuated to a protective configuration to protect a single respective fragile member of a plurality of fragile members during a fall event (i.e., actuatable members can protect fragile members as respective pairs). However, this is not strictly required. In some implementations, multiple actuatable members can be actuated to protect fewer fragile members (e.g., in  FIG.  10 C , arm member  113  as shown in  FIGS.  10 D and  10 E  could be actuated similarly to arm member  116  in  FIG.  10 C , such that both arm members  113  and  116  protect face  411 ). As another example, fewer actuatable members can be actuated to protect a greater quantity of fragile members (e.g., in  FIGS.  7 A and  7 B , actuatable member  710  can be actuated to protect face  411 , arm member  116 , and any other fragile members of robot  100 ). 
     One difference between  FIGS.  10 D and  10 E  is the configuration of end effectors  114  and  117 . In the example of  FIG.  10 D , end effectors  114  and  117  are actuated to respective defensive configurations (closed configurations in the illustrated example, as discussed with reference to  FIGS.  3 B,  5 B, and  5 C ). In the example of  FIG.  10 E , end effectors  114  and  117  are actuated to respective compound defensive configurations. In particular, in  FIG.  10 E  end effectors  114  and  117  are actuated to closed configurations, as discussed with reference to  FIGS.  3 B,  5 B, and  5 C , and end effectors  114  and  117  are actuated to contracted configurations, where end effectors  114  and  117  are actuated to move towards torso  110 . The illustrated defensive configurations are merely exemplary, and any defensive configurations of combinations of defensive configurations could be implemented as appropriate for a given application. 
     Further, although  FIGS.  10 A,  10 B,  10 C,  10 D, and  10 E  illustrate end effectors  114  and  117  as gripper members (as discussed with reference to  FIGS.  3 A,  3 B, and  3 C ), any appropriate form of end effector could be implemented. For example, end effectors  114  and  117  in  FIGS.  10 A,  10 B,  10 C,  10 D, and  10 E  could comprise hand-shaped members, as discussed with reference to  FIGS.  5 A,  5 B, and  5 C . 
     In some implementations, at least one support structure can be coupled to the at least one actuatable member which protects the at least one actuatable member from damage during the fall event. Several examples are illustrated in  FIGS.  11 A,  11 B,  11 C,  11 D,  11 E, and  11 F  discussed below. 
       FIGS.  11 A and  11 B  illustrate an exemplary actuatable member  1110  having an end effector  1116  at an end thereof. Actuatable member  1110  includes an elbow portion  1112 , such that when actuatable member  1110  is actuated to a protective configuration, elbow support  1112  protects end effector  1116  similar to as discussed above regarding  FIGS.  10 A,  10 B,  10 C,  10 D, and  10 E . Actuatable member  1110  is illustrated as an arm member similar to arm members  113  or  116  discussed above; however, any other form of actuatable member could be implemented as appropriate for a given application. 
     Because elbow portion  1112  is actuated to a protective configuration in which elbow portion  1112  will receive impact during a fall event, it can be helpful to protect elbow portion  1112  from damage with a support structure. In the example of  FIG.  11 A , such support structure comprises a pad  1114  (an elbow pad in the illustration) positioned proximate elbow portion  1112 , to protect elbow  1112  during a fall event. Pad  1114  could be made of a material which disperses or absorbs impact, reducing the likelihood or severity of damage to elbow portion  1112 . For example, pad  1114  could be made of a hard and resilient rubber or other polymer. The support structure (pad  1114 ) can be coupled to actuatable member  1110 , in a support configuration where elbow portion  1112  is supported or protected. In some implementations, this coupling can be static (i.e., the support structure is always in the support configuration). 
     In other implementations, the support structure can be actuated to the support configuration as needed. In the example of  FIG.  11 B , the support structure (pad  1114 ) is positioned in a stowed configuration in which the support structure is stowed. In the example of  FIG.  11 B , the stowed configuration is shown where pad  1114  is positioned away from elbow portion  1112 . Such a stowed configuration can advantageously avoid the support structure encumbering or otherwise limiting movement of elbow portion  1112 . In such an implementation, the support structure is actuatable to the support configuration shown in  FIG.  11 A . In response to detecting the fall event as in act  202  of method  200  in  FIG.  2   , the at least one support structure is actuated from the stowed configuration of  FIG.  11 B  to the support configuration of  FIG.  11 A . In the example of  FIGS.  11 A and  11 B , the pad  1114  is actuated to cover the elbow portion  1112 . After the robot recovers from the fall event (e.g. stands back up, is helped back up, etcetera), the support structure can be actuated from the support configuration to the stowed configuration. 
       FIGS.  12 A and  12 B  illustrate an exemplary actuatable member  1110  having an end effector  1116  at an end thereof, similar to  FIGS.  11 A and  11 B . Description of  FIGS.  11 A and  11 B  is applicable to  FIGS.  12 A and  12 B  unless context dictates otherwise. As with  FIGS.  11 A and  11 B , in  FIGS.  12 A and  12 B  actuatable member  1110  also includes an elbow portion  1112 , such that when actuatable member  1110  is actuated to a protective configuration, elbow portion  1112  protects end effector  1116  similar to as discussed above regarding  FIGS.  10 A,  10 B,  10 C,  10 D, and  10 E . Actuatable member  1110  is illustrated as an arm member similar to arm members  113  or  116  discussed above; however, any other form of actuatable member could be implemented as appropriate for a given application. 
     One difference between  FIGS.  12 A and  12 B , compared to  FIGS.  11 A and  11 B , is that the support structure which protects elbow portion  1112  is of a different form. In the example of  FIG.  12 A , such support structure comprises pedestals  1202  and  1204  (alternatively called protrusions) positioned proximate elbow portion  1112 , to protect elbow portion  1112  during a fall event. The support structure (pedestals  1202  and  1204 ) can be coupled to actuatable member  1110 , in a support configuration where elbow portion  1112  is supported or protected. For example, pedestals  1202  and  1204  could be coupled to rigid structural elements of actuatable member  1110  (such as skeletal support components, similar to human bones), instead of being coupled to elbow portion  1112  itself. In this way, impact during a fall event is transferred to rigid, robust components of a robot, instead of being imparted on a more fragile joint component. In some implementations, the coupling between pedestals  1202  and  1204  and actuatable member  1110  can be static (i.e., the support structure is always in the support configuration). 
     In other implementations, the support structure can be actuated to the support configuration as needed. In the example of  FIG.  12 B , the support structure (pedestals  1202  and  1204 ) are positioned in a stowed configuration in which the support structure is stowed. In the example of  FIG.  12 B , the stowed configuration is shown where pedestals  1202  and  1204  are retracted into a housing of the actuatable member  1110  (shown as dashed lines in  FIG.  12 B ). Such a stowed configuration can advantageously avoid the support structure encumbering or otherwise limiting movement of elbow portion  1112 , or having an unpleasant appearance. In such an implementation, the support structure is actuatable to the support configuration shown in  FIG.  12 A . In response to detecting the fall event as in act  202  of method  200  in  FIG.  2   , the at least one support structure is actuated from the stowed configuration of  FIG.  12 B  to the support configuration of  FIG.  12 A . In the example of  FIGS.  12 A and  12 B , the pedestals  1202  and  1204  are actuated to extends outwards away from the actuatable member  1110 . After the robot recovers from the fall event (e.g. stands back up, is helped back up, etcetera), the support structure can be actuated from the support configuration to the stowed configuration. 
     Although  FIGS.  12 A and  12 B  illustrate a support structure which comprises two pedestals, the support structure could comprise any number of pedestals as appropriate for a given application. 
       FIGS.  13 A and  13 B  illustrate an exemplary actuatable member  1110  having an end effector  1116  at an end thereof, similar to  FIGS.  11 A,  11 B,  12 A, and  12 B . Description of  FIGS.  11 A,  11 B,  12 A, and  12 B  is applicable to  FIGS.  13 A and  13 B  unless context dictates otherwise. As with  FIGS.  11 A,  11 B,  12 A, and  12 B , in  FIGS.  13 A and  13 B  actuatable member  1110  also includes an elbow portion  1112 , such that when actuatable member  1110  is actuated to a protective configuration, elbow portion  1112  protects end effector  1116  similar to as discussed above regarding  FIGS.  10 A,  10 B,  10 C,  10 D, and  10 E . Actuatable member  1110  is illustrated as an arm member similar to arm members  113  or  116  discussed above; however, any other form of actuatable member could be implemented as appropriate for a given application. 
     Similar to the example of  FIGS.  12 A and  12 B , the support structure of  FIGS.  13 A and  13 B  comprises protrusions  1302  and  1304  positioned proximate elbow portion  1112 , to protect elbow  1112  during a fall event. In  FIGS.  13 A and  13 B  however, protrusions  1302  and  1304  are springs, which can absorb impact or provide cushioning during a fall event. The support structure (springs  1302  and  1304 ) can be coupled to actuatable member  1110 , in a support configuration where elbow portion  1112  is supported or protected. For example, springs  1302  and  1304  could be coupled to rigid structural elements of actuatable member  1110  (such as skeletal support components, similar to human bones), instead of being coupled to elbow portion  1112  itself. In this way, impact during a fall event is transferred to rigid, robust components of a robot, instead of being imparted on a more fragile joint component. Alternatively, springs  1302  and  1304  could be coupled to elbow portion  1112 , since springs will absorb impact (reduce momentum over a greater period of time) instead of quickly transferring such impact directly to elbow portion  1112 . In some implementations, the coupling between springs  1302  and  1304  and actuatable member  1110  can be static (i.e., the support structure is always in the support configuration). 
     In other implementations, the support structure can be actuated to the support configuration as needed. In the example of  FIG.  13 B , the support structure (springs  1302  and  1304 ) are positioned in a stowed configuration in which the support structure is stowed. In the example of  FIG.  13 B , the stowed configuration is shown where springs  1302  and  1304  are retracted into a housing of the actuatable member  1110 . Such a stowed configuration can advantageously avoid the support structure encumbering or otherwise limiting movement of elbow portion  1112 , or having an unpleasant appearance. In such an implementation, the support structure is actuatable to the support configuration shown in  FIG.  13 A . In response to detecting the fall event as in act  202  of method  200  in  FIG.  2   , the at least one support structure is actuated from the stowed configuration of  FIG.  13 B  to the support configuration of  FIG.  13 A . In the example of  FIGS.  13 A and  13 B , the springs  1302  and  1304  are actuated to extends outwards away from the actuatable member  1110 . After the robot recovers from the fall event (e.g. stands back up, is helped back up, etcetera), the at least one support member can be actuated from the support configuration to the stowed configuration. 
     Although  FIGS.  13 A and  13 B  illustrate a support structure which comprises two springs, the support structure could comprise any number of springs as appropriate for a given application. 
     The examples of  FIGS.  11 A,  11 B,  12 A,  12 B,  13 A, and  13 B  show support structures for supporting elbow joints during a fall event. However, similar support structure could be implemented for any actuatable members, as appropriate for a given application. 
     Throughout this specification and the appended claims the term “communicative” as in “communicative coupling” and in variants such as “communicatively coupled,” is generally used to refer to any engineered arrangement for transferring and/or exchanging information. For example, a communicative coupling may be achieved through a variety of different media and/or forms of communicative pathways, including without limitation: electrically conductive pathways (e.g., electrically conductive wires, electrically conductive traces), magnetic pathways (e.g., magnetic media), wireless signal transfer (e.g., radio frequency antennae), and/or optical pathways (e.g., optical fiber). Exemplary communicative couplings include, but are not limited to: electrical couplings, magnetic couplings, radio frequency couplings, and/or optical couplings. 
     Throughout this specification and the appended claims, infinitive verb forms are often used. Examples include, without limitation: “to encode,” “to provide,” “to store,” 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, encode,” “to, at least, provide,” “to, at least, store,” 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 computer systems and computing environments provided. 
     This specification provides various implementations and embodiments in the form of block diagrams, schematics, flowcharts, and examples. A person skilled in the art will understand that any function and/or operation within such block diagrams, schematics, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, and/or firmware. For example, the various embodiments disclosed herein, in whole or in part, can be equivalently implemented in one or more: application-specific integrated circuit(s) (i.e., ASICs); standard integrated circuit(s); computer program(s) executed by any number of computers (e.g., program(s) running on any number of computer systems); program(s) executed by any number of controllers (e.g., microcontrollers); and/or program(s) executed by any number of processors (e.g., microprocessors, central processing units, graphical processing units), as well as in firmware, and in any combination of the foregoing. 
     Throughout this specification and the appended claims, a “memory” or “storage medium” is a processor-readable medium that is an electronic, magnetic, optical, electromagnetic, infrared, semiconductor, or other physical device or means that contains or stores processor data, data objects, logic, instructions, and/or programs. When data, data objects, logic, instructions, and/or programs are implemented as software and stored in a memory or storage medium, such can be stored in any suitable processor-readable medium for use by any suitable processor-related instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the data, data objects, logic, instructions, and/or programs from the memory or storage medium and perform various acts or manipulations (i.e., processing steps) thereon and/or in response thereto. Thus, a “non-transitory processor-readable storage medium” can be any element that stores the data, data objects, logic, instructions, and/or programs for use by or in connection with the instruction execution system, apparatus, and/or device. As specific non-limiting examples, the processor-readable medium can be: a portable computer diskette (magnetic, compact flash card, secure digital, or the like), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM, EEPROM, or Flash memory), a portable compact disc read-only memory (CDROM), digital tape, and/or any other non-transitory medium. 
     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.