SAFE OPERATION OF MACHINERY USING POTENTIAL OCCUPANCY ENVELOPES
Various embodiments for enforcing safe operation of machinery performing an activity in a three-dimensional (3D) workspace includes computationally generating a 3D spatial representation of the workspace; computationally mapping 3D regions of the workspace corresponding to space occupied by the machinery and a human; and based thereon, restricting operation of the machinery in accordance with a safety protocol during physical performance of the activity.
1 . A safety system for enforcing safe operation of machinery performing an activity in a three-dimensional (3D) workspace, the system comprising:
a computer memory for storing (i) a model of the machinery and its permitted movements and (ii) a safety protocol specifying speed restrictions of the machinery in proximity to a human and a minimum separation distance between the machinery and a human; and
a processor configured to:
computationally generate, from the stored images, a 3D spatial representation of the workspace;
map, via a mapping module, a first 3D region of the workspace corresponding to space occupied by the machinery within the workspace augmented by a 3D envelope around the machinery spanning all movements executed by the machinery during performance of the activity;
map, via the mapping module, a second 3D region of the workspace corresponding to a portion of the first 3D region predictively occupied by the machinery during an interval beginning at a current time;
identify a third 3D region of the workspace corresponding to space occupied or potentially occupied by a human within the workspace augmented by a 3D envelope around the human corresponding to anticipated movements of the human within the workspace during the interval; and
during physical performance of the activity, restrict operation of the machinery in accordance with the safety protocol based on proximity between the second and third regions.
2 . The safety system of claim 1 , wherein the interval corresponds to a time required to bring the machinery to a safe state.
3 . The safety system of claim 1 , further comprising a plurality of sensors distributed about the workspace, each of the sensors being associated with a grid of pixels for recording images of a portion of the workspace within a sensor field of view, the workspace portions collectively covering the entire workspace, wherein the mapping module is configured to compute the first 3D region of the workspace based on images generated by the sensors during performance of the activity by the machinery.
4 . The safety system of claim 1 , further comprising a simulation module, the mapping module being configured to compute the first 3D region of the workspace based on simulation, by the simulation module, of performance of the activity by the machinery.
5 . The safety system of claim 1 , wherein the interval is based at least in part on a worst-case time required to bring the machinery to a safe state.
6 . The safety system of claim 1 , wherein the interval is based at least in part on a worst-case stopping time of the machinery in a direction toward the third 3D region of the workspace.
7 . The safety system of claim 1 , wherein the first 3D region is confined to a spatial region reachable by the machinery only during performance of the activity.
8 . The safety system of claim 1 , wherein the first 3D region includes a global spatial region reachable by the machinery during performance of any activity.
9 . The safety system of claim 1 , wherein the interval is based at least in part on a current state specifying a position, velocity and acceleration of the machinery.
10 . The safety system of claim 9 , wherein the interval is further based on programmed movements of the machinery in performing the activity beginning at the current time.
11 . The safety system of claim 1 , wherein the workspace is computationally represented as a plurality of voxels.
12 . The safety system of claim 1 , further comprising an object-recognition module for recognizing the human and the machinery and movements thereof.
13 . The safety system of claim 3 , wherein the workspace portions collectively cover the entire workspace.
14 . The safety system of claim 1 , wherein the first 3D region is divided into a plurality of nested, spatially distinct 3D subzones.
15 . The safety system of claim 14 , wherein overlap between the second 3D region and each of the subzones results in a different degree of alteration of the operation of the machinery.
16 . The safety system of claim 1 , wherein the processor is further configured to recognize a workpiece being handled by the machinery and treat the workpiece as a portion thereof in identifying the first 3D region.
17 . The safety system of claim 1 , wherein the processor is further configured to recognize a workpiece being handled by the human and treat the workpiece as a portion of the human in identifying the third 3D region.
18 . The safety system of claim 1 , wherein the processor is configured to dynamically control a maximum velocity of the machinery so as to prevent contact between the machinery and a human except when the machinery is stopped.
19 . The safety system of claim 1 , wherein the processor is configured to compute the anticipated movements of the human within the workspace during the interval based on a current direction, velocity and acceleration of the human.
20 . The safety system of claim 19 , wherein computation of the anticipated movements of the human within the workspace during the interval is further based on a kinematic model of human motion.
21 . The safety system of claim 1 , wherein the processor is further configured to stop the machinery during physical performance of the activity if the machinery is determined to be operating outside the first 3D region.
22 . The safety system of claim 1 , wherein the processor is further configured to preemptively stop the machinery during physical performance of the activity based on predicted operation of the machinery inside the third 3D region during the interval.
23 . A method of enforcing safe operation of machinery performing an activity in a three-dimensional (3D) workspace, the method comprising the steps of:
electronically storing (i) a model of the machinery and its permitted movements and (ii) a safety protocol specifying speed restrictions of the machinery in proximity to a human and a minimum separation distance between the machinery and a human;
computationally generating, from the stored images, a 3D spatial representation of the workspace;
computationally mapping a first 3D region of the workspace corresponding to space occupied by the machinery within the workspace augmented by a 3D envelope around the machinery spanning all movements executed by the machinery during performance of the activity;
computationally mapping a second 3D region of the workspace corresponding to a portion of the first 3D region predictively occupied by the machinery during an interval beginning at a current time;
computationally identifying a third 3D region of the workspace corresponding to space occupied or potentially occupied by a human within the workspace augmented by a 3D envelope around the human corresponding to anticipated movements of the human within the workspace during the interval; and
during physical performance of the activity, restricting operation of the machinery in accordance with the safety protocol based on proximity between the second and third regions.
24 . The method of claim 23 , wherein the interval corresponds to a time required to bring the machinery to a safe state.
25 . The method of claim 23 , further comprising providing a plurality of sensors distributed about the workspace, each of the sensors being associated with a grid of pixels for recording images of a portion of the workspace within a sensor field of view, the workspace portions collectively covering the entire workspace, wherein the first 3D region of the workspace is mapped based on images generated by the sensors during performance of the activity by the machinery.
26 . The method of claim 23 , wherein the first 3D region of the workspace is mapped based on computational simulation of performance of the activity by the machinery.
27 . The method of claim 23 , wherein the interval is based at least in part on a worst-case time required to bring the machinery to a safe state.
28 . The method of claim 23 , wherein the interval is based at least in part on a worst-case stopping time of the machinery in a direction toward the third 3D region of the workspace.
29 . The method of claim 23 , wherein the first 3D region is confined to a spatial region reachable by the machinery only during performance of the activity.
30 . The method of claim 23 , wherein the first 3D region includes a global spatial region reachable by the machinery during performance of any activity.
31 . The method of claim 23 , wherein the interval is based at least in part on a current state specifying a position, velocity and acceleration of the machinery.
32 . The method of claim 31 , wherein the interval is further based on programmed movements of the machinery in performing the activity beginning at the current time.
33 . The method of claim 23 , wherein the workspace is computationally represented as a plurality of voxels.
34 . The method of claim 23 , further comprising the step of computationally recognizing the human and the machinery and movements thereof.
35 . The method of claim 25 , wherein the workspace portions collectively cover the entire workspace.
36 . The method of claim 23 , wherein the first 3D region is divided into a plurality of nested, spatially distinct 3D subzones.
37 . The method of claim 36 , wherein overlap between the second 3D region and each of the subzones results in a different degree of alteration of the operation of the machinery.
38 . The method of claim 23 , further comprising the steps of recognizing a workpiece being handled by the machinery and treating the workpiece as a portion thereof in identifying the first 3D region.
39 . The method of claim 23 , further comprising the step of recognizing a workpiece being handled by the human and treating the workpiece as a portion of the human in identifying the third 3D region.
40 . The method of claim 23 , further comprising the step of dynamically controlling a maximum velocity of the machinery so as to prevent contact between the machinery and a human except when the machinery is stopped.
41 . The method of claim 23 , wherein the anticipated movements of the human within the workspace during the interval are computed based on a current direction, velocity and acceleration of the human.
42 . The method of claim 41 , wherein computation of the anticipated movements of the human within the workspace during the interval is further based on a kinematic model of human motion.
43 . The method of claim 23 , further comprising the step of stopping the machinery during physical performance of the activity if the machinery is determined to be operating outside the first 3D region.
44 . The method of claim 23 , further comprising the step of preemptively stopping the machinery during physical performance of the activity based on predicted operation of the machinery inside the third 3D region during the interval.