Mobile Robot

Abstract

The mobile robot can include a safety system configured to stop the mobile robot when an object is detected inside a safety zone. The size of the safety zone can vary based on the speed of the robot. The robot can predict the future safety zone and determine whether an object will be inside the predicted future safety zone. The robot can modify its trajectory, such as by slowing down, so that the robot's actual safety zone avoids the object. This allows the mobile robot to avoid the object without stopping and without activating the robot's safety system. The mobile robot is configured to proactively predict potential safety events and take action to avoid the predicted safety events.

Description

[Technical Field]

[0001] Some embodiments disclosed herein relate to clearance systems for mobile robots, such as for navigation and / or collision avoidance. [Background technology]

[0002] Safety systems are known to enable mobile robots to perform emergency stops, such as collision avoidance, but these emergency stops can cause wear and tear on the robot, impair its stability, and lead to delays and inefficiencies. Summary of the Invention

[0003] The invention described herein has multiple aspects, no single one of which alone provides its desirable properties. Without intending to limit the scope of the claims, the following briefly describes some features of the disclosure.

[0004] According to one aspect of the present disclosure, a mobile robot may include a drive system configured to move the mobile robot, an environmental sensor configured to identify one or more objects in an environment surrounding the mobile robot, and a safety stop system. The safety stop system may be configured to determine a safety zone. The safety zone may have a size based at least in part on the speed of the mobile robot. The safety system may determine whether an object identified by the environmental sensor is within the safety zone and, in response to determining that the object is within the safety zone, may activate an emergency brake to stop the mobile robot. The mobile robot may include a safety stop avoidance system. The safety stop avoidance system may be configured to obtain (access) trajectory information regarding the mobile robot's planned travel path, recognize an object outside the current safety zone, determine, based at least in part on the trajectory information, that the identified object may enter the safety zone in the future, which is predicted to cause a safe stop event, and control the drive system to slow the mobile robot and reduce the size of the safety zone to avoid the safe stop event.

[0005] The safety stop system may be hardware-based and / or the safety stop avoidance system may be software-based. The size of the safety zone may be based at least in part on user-adjustable parameters. The predicted future size of the safety zone may also be based at least in part on user-adjustable parameters. The mobile robot of this embodiment may further include a navigation system. The safety stop system, the safety stop avoidance system, and the navigation system may operate in parallel as separate modules. The mobile robot of this embodiment may further include a navigation system. The navigation system may be configured to modify the planned travel trajectory of the mobile robot based at least in part on a notification that the safety stop avoidance system has slowed the mobile robot.

[0006] According to one aspect of the present disclosure, a mobile robot may include a drive system configured to move the mobile robot, a sensor configured to recognize one or more objects near the mobile robot, and a safety system configured to stop the mobile robot when an object is detected within a safety zone. The size may be based at least in part on the speed of the mobile robot. The mobile robot of this aspect may also include a clearance system. The clearance system may be configured to recognize objects using the sensor, acquire trajectory information regarding a planned travel path of the mobile robot, determine a first future safety zone based at least in part on the trajectory information including a first speed, and determine that an object is within the first future safety zone. The first future safety zone may have a first size corresponding to the first speed. The clearance system may determine a second future safety zone having a second size corresponding to a second speed. The second size may be smaller than the first size such that the object is located outside the second future safety zone. The mobile robot of this aspect may modify the trajectory information to use the second speed.

[0007] The second speed may be less than the first speed. The sensor may include a laser scanner. The clearance system may be configured to determine the first future safety zone to have the same first size as the safety zone for the first speed. The safety system and the clearance system may operate simultaneously in parallel.

[0008] According to one aspect of the present disclosure, a mobile robot may include a drive system configured to move the mobile robot. The mobile robot of this aspect may include environmental sensors configured to recognize one or more objects in an environment proximate to the mobile robot. The mobile robot of this aspect may include a safety system configured to execute a safety stop when an object is detected within an active safety zone of the mobile robot. The mobile robot of this aspect may include a navigation system. The navigation system may be configured to generate trajectory information based on the position, a target position, and one or more objects located in the environment. The trajectory information may include a route from the position to the target position and one or more velocities along the route. The navigation system may be configured to determine one or more predicted safety zones based on the trajectory information, determine that a recognized object will be within one of the one or more predicted safety zones, and adjust the trajectory information to generate corrective trajectory information such that the recognized object is outside the one or more predicted safety zones.

[0009] The size of the safety zone may be based at least in part on the speed of the mobile robot. The navigation system may be configured to adjust the trajectory information by reducing the speed of the mobile robot. The navigation system may be configured to adjust the trajectory information by changing the route of the mobile robot. The navigation system may be configured to determine a plurality of predicted safety zones based on the trajectory information and compare the position of the object to the plurality of predicted safety zones.

[0010] According to one aspect of the present disclosure, a robot may include a safety system configured to detect safety events and take safety actions in response to the detected safety events. The robot of this aspect may also include a clearance system configured to predict future safety events and take actions to avoid the predicted future safety events.

[0011] The safety system may be configured to stop the robot when an object is recognized inside the safety zone. The clearance system may be configured to slow the robot when an object is recognized outside the safety zone and inside the predicted future safety zone. The size of the safety zone and / or the size of the predicted future safety zone may vary based at least in part on the speed of the robot. The clearance system may be configured to determine a reduced speed to allow the object to remain outside the safety zone and to slow the robot to the reduced speed.

[0012] Certain embodiments will be described in detail with reference to the following drawings, in which like reference numerals refer to like elements throughout the drawings. These drawings are illustrative examples, and the embodiments are not limited to the specific examples shown in the drawings. [Brief explanation of the drawings]

[0013] [Figure 1] 1 illustrates an exemplary embodiment of a mobile robot. [Figure 2] FIG. 1 is a schematic diagram of an exemplary embodiment of a mobile robot. [Figure 3] 1 shows an example of a mobile robot approaching an object. [Figure 4] Here is an example of an object activating a safety stop on a robot. [Figure 5] 1 shows an example of a mobile robot approaching an object. [Figure 6] This example shows a mobile robot slowing down to avoid a safety stop caused by an object. [Figure 7] This example shows a mobile robot passing through an object at a reduced speed. [Figure 8] This shows an example of a mobile robot moving away from an object. [Figure 9] 1 is a flowchart of an exemplary method for avoiding a safety event. DETAILED DESCRIPTION OF THE INVENTION

[0014] Various features and advantages of the systems, devices, and methods of the technology described herein will become more apparent through the following description of illustrated examples. These examples are intended to illustrate the principles of the present disclosure, and the present disclosure is not limited to these illustrated examples. Features of the illustrated examples can be modified, combined, deleted, and / or substituted, as would be apparent to one skilled in the art in light of the principles disclosed herein.

[0015] A mobile robot can be equipped with a safety system configured to perform an emergency stop when an object is detected within the robot's active safety zone. For example, the robot can apply emergency braking when a safety event occurs. An emergency stop can cause wear and tear on the robot, reduce platform stability (which could, for example, cause an item being carried by the robot to shift or fall), and / or increase the robot's travel time and reduce its efficiency. In some cases, the safety system may stop the robot in response to a safety event and hold it stationary for a period of time (e.g., approximately 2 seconds). After that period, the robot can begin moving again, but it may take several seconds to regain its original speed. Thus, each safety event can result in a delay of several seconds (e.g., approximately 7-10 seconds, although other configurations are possible).

[0016] In some embodiments, a robot may be equipped with a system for reducing and / or avoiding the occurrence of a safety event (e.g., an emergency shutdown). This can reduce wear and tear on the robot, improve robot stability, and / or shorten travel time and improve efficiency. The system can predict future safety events and modify the mobile robot's trajectory to avoid the predicted safety event. While previously described safety systems respond to safety events after they occur, this system can proactively avoid safety events. This system can look further ahead than safety systems and recognize objects that are currently outside the active safety zone and have not yet triggered a safety event. The system can predict that an object may trigger a future safety event if the robot continues along the planned path at the planned speed. The system can then slow the robot's speed to reduce the size of the safety zone so that the recognized object does not enter the safety zone and cause a safety event. This system may mimic a safety system, but it is more proactive in recognizing and avoiding predicted safety events.

[0017] FIG. 1 is a diagram illustrating an exemplary embodiment of a mobile robot 100. FIG. 2 is a schematic diagram of the mobile robot 100. The mobile robot 100 may include a chassis or housing 102 that supports various other components of the robot 100. Some components may be disposed inside the housing 102, while some components may be disposed so that they are at least partially exposed from the housing 102 to allow interaction with entities external to the housing 102. The robot 100 may include a drive system 104. The drive system 104 may be configured to move the robot 100. For example, the robot 100 may include one or more drive wheels 106 drivable by at least one motor (not visible in FIG. 1). In some embodiments, two or more drive wheels 106 may be independently driven to move the mobile robot 100 forward, backward, turn, etc. In some embodiments, the robot 100 may be turned by a steering mechanism (e.g., swiveling wheels). In some cases, one or more non-drive wheels 108 may support the robot 100. In some embodiments, the drive system 104 may include a braking system (e.g., not visible in FIG. 1 ). The braking system may be configured to stop the robot 100. The braking system may be, for example, a disc brake, a drum brake, or any suitable type of braking mechanism. In some embodiments, one or more motors (e.g., electric motor(s)) driving the drive wheels 106 may be used for braking to slow or stop the robot 100. Various other suitable drive systems may also be used, such as crawlers or legs.

[0018] In some embodiments, the robot 100 may include a speed sensor that can provide information regarding the speed or velocity of the mobile robot 100. The speed sensor 110 may measure the rotation of a drive wheel, a motor component, or other component. In some embodiments, the motor may output the speed information. In some embodiments, the speed sensor 110 may determine speed using a GPS or other suitable device or method.

[0019] The robot 100 may include an environmental sensor 112 that can be used to sense or measure the environment around the robot 100. The environmental sensor 112 may be, for example, a lidar system. The environmental sensor 112 may include at least one laser capable of emitting laser pulses over a range of angles. The environmental sensor 112 may include a photodetector capable of receiving light from the laser pulses reflected by the environment (e.g., objects) around the robot 100. The received light may be used to determine the position of objects around the robot 100. For example, the direction of emission of the laser pulse and / or the direction of the received light can indicate the direction of the object. The timing (time difference) of the emission of the laser pulse and / or the reception of the light (e.g., the time-of-flight of the light) can indicate the distance from the robot to the object. The housing 102 of the robot 100 may include an opening 114, such as a generally horizontal slit, that allows light (e.g., over a range of angles) to enter and exit the environmental sensor 112 of the robot 100. Various other types of environmental sensors 112 may also be used, such as cameras, video analytics systems that analyze footage from cameras mounted on the robot 100 to recognize objects and other environmental features, sonar systems, and / or thermal sensors.

[0020] The system may include a controller 116 that can operate various functions of the robot 100. For example, the controller 116 may interpret information from the environmental sensors 112 to recognize objects, determine distance to or location of objects, operate the drive system 104, perform navigation and / or collision avoidance operations, perform safety stops or emergency braking, take action to avoid safety events described herein, or various other features and functions of the robot 100. Various functions of the robot 100 disclosed herein may be implemented by the controller 116, even if not specifically mentioned as such.

[0021] The robot 100 may include at least one processor 118. The processor 118 may be a hardware processor. The processor 118 may include circuitry configured to perform operations to achieve the various functions and features described herein. In some embodiments, the robot 100 may include multiple processors 118, and different tasks may be performed by different processors 118. The robot 100 may include memory 120. The memory 120 may be computer-readable memory (e.g., non-transitory computer-readable memory). The memory 120 may include RAM, ROM, non-volatile memory, flash memory, a hard disk, or any other suitable type of memory. In some embodiments, the robot 100 may include multiple memory components. The multiple memory components may store different types of information or instructions for different functions or features. The memory 120 may store instructions executable by the at least one processor 118 to operate the controller 116 and / or perform the various functions and features disclosed herein. In some embodiments, these functions and / or features may be realized by integrated circuits or other dedicated processors specially configured to perform the functions and features disclosed herein.

[0022] The controller 116 may, in some cases, include multiple control modules. Different control modules (e.g., different processors 118 and / or different software instruction sets) may perform different tasks or functions. As an example, a first control module or safety control module may be configured to recognize a safety event and perform an emergency shutdown in response to the recognized safety event. A second control module may be configured to predict and avoid a safety event, as described herein. The first control module or safety control module may be safety rated and subject to more rigorous inspection and testing. In some cases, a safety rated module may be monitored during operation, and any detected failures or malfunctions may be addressed (e.g., by shutting down the robot). The first module or safety module may be hardware-based (e.g., with no software components), which may facilitate safety certification of the safety module. In some embodiments, the safety module may have a relatively simple software module compared to the second module, which may facilitate safety certification of the safety module. In some cases, the second control module configured to predict and prevent safety events is not subject to safety compliance, and therefore the second control module may be implemented by software and / or a more complex set of instructions.

[0023] The robot 100 may include a communication interface 122 that can be used to transmit information from the robot 100 and / or receive information from an external device. The communication interface 122 may be wireless and may use Wi-Fi, Bluetooth, or other suitable wireless communication protocols. In some embodiments, the communication interface 122 may use a wired connection. For example, the communication interface 122 may include a port or plug. The port or plug may be configured to connect to a corresponding plug or port coupled to an external device to enable communication between the communication interface 122 and the external device. The port or plug may be, for example, a USB port, although various types of ports or other wired connections may also be used. In some cases, a user may couple a laptop, smartphone, or other computing device to the robot 100 via the communication interface to adjust parameters of the robot 100, diagnose problems with the robot 100, update functions of the robot 100, etc.

[0024] The robot 100 may include a user interface 124 that can be used to receive input from a user and / or provide output (e.g., information) to a user. The user interface 124 may include one or more buttons 126, switches, dials, or other user input elements, a touchscreen, a display, one or more lights, speakers, a microphone, etc. In some cases, a user may provide input to adjust parameters of the robot 100, such as parameters of a safety system and / or a system configured to reduce a safety event.

[0025] The robot 100 may include a power source 128. The power source 128 may be a battery. The battery may be rechargeable, and the robot 100 may be configured to dock with a recharging station (e.g., via an electrical interface) that accommodates the battery. The power source 128 may provide power to operate the drive system 104 (e.g., one or more electric motors), various sensors, controllers, and other systems disclosed herein. The power source 128 may provide DC or AC power. Any suitable type of power source 128 may be used.

[0026] The robot 100 may include a navigation system 130. The navigation system 130 may be used to determine trajectory information for the robot 100. The navigation system 130 may receive a destination point and / or one or more waypoints, such as from the user interface 124 or the communication interface 122. The navigation system 130 may receive environmental information (e.g., the location of an object) from the environmental sensors 112 and use the information to determine trajectory information for navigating the robot 100 (e.g., toward the destination point). The trajectory information may include a path or route. The trajectory information may include one or more speeds or velocities of the robot (e.g., at one or more portions or positions along the path or route). In some cases, the navigation system 130 may determine intermediate waypoints based on the environmental information. In some embodiments, the navigation system 130 may modify the trajectory information while the robot 100 is moving. For example, if an object moves or if a new object is detected (e.g., by the environmental sensors 112), the navigation system 130 may determine a change in the path or route of the robot 100 and / or may determine a change in the speed of the robot 100.

[0027] The robot 100 may include a safety system 132. The safety system 132 may determine that a safety event has occurred and may perform an emergency stop in response to the safety event. The safety system 132 is described in connection with FIGS. 3 and 4. The system 132 may determine whether an object 140 is within the robot's active safety zone 142. The safety zone 142 may have a generally sector-shaped or trapezoidal shape extending in front of the robot 100 along the direction of the robot's travel. The safety zone 142 may extend in a direction away from the robot 100. The safety zone 142 may extend a predetermined distance in front of the robot 100, which may be approximately 0.5 meters, approximately 1 meter, approximately 1.5 meters, approximately 2 meters, approximately 2.5 meters, approximately 3 meters, approximately 3.5 meters, approximately 4 meters, or more, or any value or range therebetween, although other configurations are possible. The size of the safety zone 142 may vary based on the speed of the robot 100. The safety zone 142 may be larger when the robot 100 is moving faster and smaller when the robot 100 is moving slower. The safety system 132 may determine the current safety zone 142 based on speed information (e.g., from the speed sensor 110), etc. The safety system 132 may determine whether an object is present inside the current safety zone 142. If an object is detected inside the safety zone 142, the safety system 132 may implement a safety procedure, such as stopping the robot 100. In some configurations, the safety system 132 may recognize the object 140, after which the safety system 132 may determine whether the object 140 is present inside the safety zone 142. If the object is present inside the safety zone 142, the safety system may trigger a safety procedure, such as stopping the robot 100. The safety system 132 may use environmental sensors 112 (e.g., Lidar or other laser scanning systems) to locate the object.

[0028] A safety procedure may include activating a braking system or mechanism, for example, to apply emergency braking. In some cases, a safety procedure may include activating one or more electric motors to stop the robot 100. A safety procedure may be configured to stop the robot as quickly as practical. A safety procedure may require the robot 100 to remain stationary for a predetermined period of time (e.g., approximately 1, 2, 3, 4, 5, 7, 10 seconds, or any value or range therebetween), after which the robot 100 is allowed to begin moving again. When the robot 100 begins moving again, a safety procedure may cause the robot to begin moving gradually before allowing it to return to its normal speed (e.g., its speed before the safety event). In some embodiments, the navigation system 130 may change the path or route of the robot 100 (e.g., to avoid the object that triggered the safety event). In some cases, a safety event may initiate a re-routing action by the navigation system 130. A safety procedure may delay the robot 100 from reaching its destination. The delay may be about 3 seconds, about 5 seconds, about 7 seconds, about 10 seconds, about 12 seconds, about 15 seconds, about 20 seconds, or more, or any value or range therebetween, although other configurations are possible.

[0029] In some embodiments, the safety zone 142 may include a buffer area around at least a portion of the robot 100. The buffer area may be polygonal or have other shapes and may extend a predetermined distance from at least one end of the robot 100. For example, this distance may be approximately 50 mm, approximately 75 mm, approximately 100 mm, approximately 125 mm, approximately 150 mm, approximately 175 mm, approximately 200 mm, approximately 225 mm, approximately 250 mm, approximately 275 mm, approximately 300 mm, approximately 325 mm, approximately 350 mm, approximately 375 mm, approximately 400 mm, approximately 425 mm, approximately 450 mm, approximately 475 mm, approximately 500 mm, or more, or any value or range therebetween, although other configurations are possible. The buffer area may extend around the entire perimeter of the robot 100 in some cases, or around only a portion of the robot 100 in other configurations. In the examples of FIGS. 3 and 4 , the buffer area covers the right and left sides of the robot. The buffer area may also cover the front of the robot (e.g., overlapping a portion of the front safety zone that changes based on the robot's speed). In some cases, the buffer area need not cover the front of the robot 100 because the front safety zone already covers the front of the robot 100. In some configurations, the buffer area need not cover the rear of the robot 100, for example, if the robot cannot move backward. Many configurations are possible. In some cases, the buffer area does not change based on the robot's speed or velocity. The buffer area may be static, and the front safety zone may be dynamic, as described herein. In some cases, if an object is detected inside the buffer area, the safety system 132 may execute the same safety procedure that may be triggered by a dynamic front safety zone. In some embodiments, the buffer area can be omitted. Alternatively, the buffer area may be configured to trigger a different safety action than the dynamic front safety zone.

[0030] FIG. 3 illustrates an example of the robot 100 moving along a path 144 toward a target location 146. The target location 146 may be a final or ending destination or one of the intermediate waypoints along the path 144. The robot 100 may move forward at a constant speed, as indicated by the arrow. A current safety zone 142 may extend ahead of the robot 100. The size of the safety zone 142 may be based at least in part on the speed of the robot 100. In FIG. 3, an object 140 is generally ahead of the robot 100 and is located outside the safety zone 142. Because the object 140 is located outside the safety zone, the safety system 132 does not slow or stop the robot 100 or implement other safety procedures. Therefore, the robot 100 can continue moving forward and reach the situation shown in FIG. 4. FIG. 4 illustrates an example in which the robot 100 has approached the object 140 further. At this point in FIG. 4, the safety zone 142 overlaps a portion of the object 140. The safety system 132 may determine that the object 140 is located inside the safety zone 142 and may execute safety procedures in response to that determination. For example, the robot 100 may apply emergency braking or otherwise stop.

[0031] Referring to FIG. 2 , the robot 100 may include a clearance system 134. The clearance system 134 may be configured to prevent or mitigate the occurrence of a safety event. The clearance system 134 may be configured to mimic the safety system 132, but before the safety system 132 is activated, the clearance system 134 can take proactive measures to prevent the safety system 132 from activating. The clearance system 134 may predict that the safety system 132 will activate a safety event and, in some cases, may slow down the robot 100 to prevent the safety event from occurring. The clearance system 134 may use the same information as the safety system 132 (e.g., information from the environmental sensors 112). The clearance system 134 may respond (take actions) based on an object recognized as being outside the current safety zone or active safety zone 142.

[0032] 5-8 illustrate examples in which the clearance system 134 is used to avoid a safety event. In FIG. 5, the robot 100 is moving along a path 144 toward a target location 146. The target location 146 may be a final destination or one of the intermediate waypoints along the path 144. In FIG. 5, the robot 100 is moving forward at a first velocity (e.g., a relatively high velocity), as indicated by the arrow. The active or current safety zone 142 may extend ahead of the robot 100 and may have a first size (e.g., a relatively large size) corresponding to the first velocity. The object 140 is generally ahead of the robot 100 and is located outside the safety zone 142, similar to the example of FIG. 3. In some embodiments, the safety system 132 does not take any action because the object 140 is located outside the active safety zone 142.

[0033] However, the clearance system 134 may take action to reduce the speed of the robot 100. The clearance system 134 may determine that the object will be located inside a predicted future safety zone (future safety zone) 148 (e.g., shown by a dashed line). The clearance system 134 may determine the location and size of the predicted future safety zone 148 based at least in part on trajectory information (which may be stored in the memory 120, for example). The trajectory information may include a planned path or direction of travel and a planned speed or velocity. The location and / or orientation of the predicted future safety zone 148 may be determined at least in part based on the planned path or direction of travel. The size of the predicted future safety zone 148 may be determined at least in part based on the planned speed or velocity. In FIG. 5 , the trajectory information of the robot 100 indicates moving straight along the path 144 at a constant first speed, so the predicted future safety zone may have the same size and orientation as the current safety zone 142. However, it is simply shifted forward to account for the forward movement of the robot 100 at a future time relative to the predicted future safe zone 148.

[0034] Many variations are possible. For example, if the trajectory information of the robot 100 includes a turn, the predicted future safety zone may be oriented in a different direction than the current or active safety zone. If the trajectory information includes an acceleration, the predicted future safety zone may be larger than the active safety zone. If the trajectory information includes a deceleration, the predicted future safety zone may be smaller than the active safety zone.

[0035] Referring to FIG. 6 , in response to determining that the object 140 is predicted to be located inside the safety zone in the future, the clearance system 134 may decelerate the robot 100 to a second speed (e.g., a relatively slow speed), as shown by the arrow in FIG. 6 . When moving at the slower speed, the size of the safety zone 142 may be smaller than the predicted future safety zone 148, thereby allowing the object 140 to remain outside the smaller safety zone 148. The trajectory information may be updated to temporarily use the second speed. The robot 100 may continue moving forward along the path 144 (e.g., without changing the path or route), albeit at the second speed (i.e., a slower speed), as shown in FIG. 7 . Once the robot 100 has passed the object 140, the robot 100 may accelerate to a first speed (i.e., a relatively fast speed), as shown in FIG. 8 .

[0036] As an example, the emergency stop example of Figures 3-4 may delay the robot's travel by a first amount (e.g., about 7-10 seconds). In contrast, a temporary deceleration to avoid a safety event, as shown in Figures 5-8, may delay the robot by a second amount (e.g., about 1-3 seconds). The second amount may be shorter than the first amount.

[0037] In some embodiments, the clearance system 134 may bring the robot to a complete stop. For example, if another robot crosses in front of the robot 100, the clearance system 134 may stop the robot 100 and wait until the other robot clears its path. However, the clearance system 134 may operate the robot 100 to decelerate more gradually than an emergency stop procedure before stopping. For example, even if the clearance system 134 reduces its speed to create a smaller safety zone that allows the robot to move forward without triggering a safety event, the clearance system 134 may determine that continuing to move forward at the reduced speed would trigger a safety event. The clearance system may then further reduce the robot's speed to avoid the safety event. This process may continue as the robot approaches the object, further reducing its speed (e.g., to keep the object outside the safety zone), until the robot stops. Such a gentle stop may reduce wear and tear on the robot and improve stability compared to emergency braking. Furthermore, the robot 100 does not need to remain stationary for a certain period of time as is required in an emergency safety stop, and can start moving again at any time.

[0038] FIG. 9 shows a flowchart of an example embodiment of a method 200 for avoiding a safety event. The method 200 may begin at block 202 with generating trajectory information. For example, the navigation system 130 may determine a path or route using information such as a location (e.g., a starting location or current location of the robot), a target location (e.g., a final destination or intermediate waypoints), and a mapping of the environment. This information may be received from an external system via the communication interface 122 or from a user via the user interface 124. In some cases, the robot may store the mapping of the environment. The navigation system 130 may determine one or more speeds of the robot 100 along the route. In some cases, the speeds may be selected to balance smooth driving and short travel times. The trajectory information may include multiple waypoints or multiple route segments, which may have different directions and / or different speeds. In some cases, the trajectory information (e.g., route information and / or speed information) may be received from an external source. The trajectory information may be determined at any suitable time, or may be determined dynamically as the robot moves from a start position to a target position.

[0039] In block 204, the robot 100 may move according to the trajectory information. For example, the robot 100 may move at a predetermined speed along a predetermined path. In block 206, the robot may recognize an object, for example, using the environmental sensors 112. For example, a laser scanner on the robot 100 may emit a laser pulse, at least a portion of which may be reflected back to a detector on the robot 100. For example, the presence and / or location of the object may be determined based on the direction of the emitted laser pulse and the time the reflected light is received.

[0040] 9 , in some embodiments, the robot 100 may determine (e.g., using the safety system 130) whether an object is located within a current active safety zone. The active safety zone may be determined using the current position of the robot 100 and the current speed of the robot 100. If the object is located within the current active safety zone, the robot 100 may perform an emergency stop, as described herein. If the object is not located within the current active safety zone, the method may proceed to block 208.

[0041] In block 208, the robot may determine a predicted future safety zone (e.g., similar to the example in FIG. 5). The predicted safety zone may be determined using trajectory information. The predicted safety zone may be determined based on a predicted position of the robot 100 at a future time and a planned speed at that future time. The predicted position may be known or determined from the robot's planned path and its planned speed along the planned path. In block 210, the object's position may be compared to the predicted safety zone. If the object is not located inside the predicted safety zone, the method returns to block 204, and the robot may continue moving according to the trajectory information. In some embodiments, the robot may repeatedly check whether the object can enter the predicted safety zone. For example, if the object moves, its new position may be identified and compared to the predicted safety zone (e.g., during the next iterative round of the clearance process). Trajectory information, such as position and / or speed, at any point along the robot's path (including the robot's initial starting point) may be used to determine the predicted safety zone in block 208.

[0042] If the object is determined to be inside the predicted safety zone, the method may proceed to block 212 and determine a possible alternative (different) future safety zone within which the object can be avoided. For example, if the object overlaps a first predicted safety zone associated with a first speed (e.g., a relatively high speed resulting in a relatively large predicted safety zone), a second future safety zone associated with a second speed (e.g., a relatively low speed resulting in a relatively small safety zone) may be determined, with the object remaining outside the second safety zone. In some embodiments, the size of the alternative safety zone may be selected to be as large as possible while still avoiding the object. In some embodiments, the size of the alternative safety zone may be configured to ensure a predetermined buffer distance between the alternative safety zone and the object. In some cases, the buffer distance may be a user-defined or user-adjustable parameter, for example, using a user interface.

[0043] At block 214, the trajectory information can be modified to decelerate the robot to a speed associated with the determined alternative safety zone. The method can return to block 204 and the robot 100 can continue moving, but using the modified trajectory information to avoid a safety event that would have occurred if the previous trajectory information had continued to be used.

[0044] In some embodiments, block 212 may be omitted. For example, when the robot determines that an object will enter inside the predicted safety zone, the robot 100 may respond by changing its trajectory, such as slowing down the robot 100 (e.g., at block 214). The method may loop back to block 204, and the robot may continue moving using the new trajectory. The new trajectory information may be used to determine a new predicted safety zone at block 208, and the method may check whether the object may be inside the new predicted safety zone at block 210. If it is determined that the object is still inside the new predicted safety zone, the trajectory of the robot 100 may be further modified at block 214, and this process may be repeated until the object is no longer inside the predicted safety zone. In this manner, the robot 100 may make incremental changes to the trajectory information until the trajectory information is sufficient to avoid a safety event for the object. The amount by which the trajectory is incrementally changed (the incremental amount of change) may be predetermined, may be adjustable by the user (e.g., using a user interface), and / or may depend on the speed or other parameters of the robot and / or the current trajectory.

[0045] In some embodiments, in block 208, multiple predicted future safety zones (anticipated future safety zones) can be determined, e.g., corresponding to multiple future time points and / or multiple future positions of the robot 100. In block 210, the multiple predicted future safety zones can be compared with the object's location. If no object is located in any of the predicted future safety zones, the robot can continue moving without modifying its trajectory information. If an object is located inside one or more predicted safety zones, the robot's speed may be reduced in a timely manner to avoid a safety event. As an example, the robot 100 may be configured to determine the predicted safety zones in time and / or distance units. An object may not be inside a predicted safety zone 0.5 seconds into the future, but may be inside the predicted safety zone 1.0 seconds into the future. In some cases, even if one or more predicted future safety zones are free of objects, the robot can begin decelerating without delay, thereby facilitating smooth braking. The earlier (farther) a potential safety event is recognized, the smoother or more gradual deceleration can be achieved. In some embodiments, the method may recognize multiple objects and analyze whether any of the multiple objects are within one or more predicted future safe zones.

[0046] In many cases, the robot's travel path can be maintained unchanged, and a safety event can be avoided by slowing the robot (e.g., as described in connection with FIGS. 5-8 ). In some cases, the robot's travel path may be altered to allow the robot 100 to avoid a safety event relative to an object. In some cases, the clearance system 134 may notify the navigation system 130 when it makes an adjustment to the robot's trajectory (e.g., speed). The navigation system 130 may then consider whether to alter the robot's route. In some cases, the navigation system 130 may operate in parallel with the clearance system 134, repeatedly evaluating whether to alter the robot's path. The notification from the clearance system 134 may be one factor that the navigation system 130 considers when deciding whether to alter its path.

[0047] In some embodiments, the safety system 132, the clearance system 134, and the navigation system 130 (or any two of them, etc.) can operate in parallel, such as by using the same input information (e.g., from the environmental sensors 112). The safety system 132 may analyze the input information to determine whether to perform a safety stop. The navigation system 130 may analyze the input information to determine whether to change the route of the robot 100. The clearance system 134 may analyze the input information to determine whether to slow the robot 100 to avoid a safety event. The clearance system 134 may be configured to avoid a safety event, while the safety system 132 may continue to operate in parallel as a backup in case, for example, an object moves inside the active safety zone without triggering any of the predicted safety zones. In some embodiments, the clearance system 134 may be implemented as part of the navigation system 130. The safety system 132 may comply with safety standards. In some embodiments, safety system 132 may be hardware-based (e.g., does not include software components), which may facilitate compliance of safety system 132 with safety standards. In some embodiments, safety system 132 may comprise a simpler software module than clearance system 134. Clearance system 134 may be a separate software module from safety system 132, which may allow clearance system 134 to perform more complex operations without having to comply with safety standards.

[0048] In some embodiments, the size of the safety zone is adjustable based on user input (e.g., via user interface 124). The user can specify a larger or smaller safety zone depending on how cautious the user wants the robot or the safety system to be. If the safety system 132 is configured to use a relatively large safety zone, the clearance system 134 may use a corresponding relatively large predicted safety zone. If the safety system 132 is configured to use a relatively small safety zone, the clearance system 134 may use a corresponding relatively small predicted safety zone. The clearance system 134 may determine the predicted safety zone based at least in part on the size of the adjustable safety zone used by the safety system. The clearance system may be configured to anticipate actions that the safety system is predicted to take in the future. This allows the clearance system to take action (e.g., slowing the robot) to prevent the safety system from taking such actions.

[0049] (Additional Information) In some embodiments, the methods, techniques, microprocessors, and / or controllers described herein are implemented by one or more specially designed computing devices. The specially designed computing devices may be hardwired to execute the techniques or may comprise digital electronic devices, such as one or more application-specific integrated circuits (ASICs) or field-programmable gate arrays (FPGAs), persistently programmed to execute the techniques. Alternatively, the specially designed computing devices may comprise one or more general-purpose hardware processors programmed to execute the techniques according to program instructions in firmware, memory, other storage, or a combination thereof. The instructions may be stored in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of non-transitory computer-readable storage medium. Such specially designed computing devices may combine custom hardwired logic, ASICs, or FPGAs with custom programming to achieve the techniques. The specially designed computing devices may be desktop computer systems, server computer systems, portable computer systems, handheld devices, network devices, or other devices or combinations of devices incorporating hardwired and / or program logic to implement the techniques.

[0050] The microprocessors or controllers described herein may be coordinated by operating system software, such as iOS, Android, Chrome OS, Windows XP, Windows Vista, Windows 7, Windows 8, Windows 10, Windows Server, Windows CE, Unix, Linux, SunOS, Solaris, iOS, Blackberry OS, VxWorks, or other compatible operating systems. In other embodiments, the computing device may be controlled by its own operating system. Traditional operating systems provide a variety of functions, such as controlling and scheduling computer processes, providing memory management, file system, networking, I / O services, and providing user interface functionality, such as a graphical user interface ("GUI"), for executing computer processes.

[0051] The microprocessors and / or controllers described herein may implement the techniques described herein using customized hardwired logic, one or more ASICs or FPGAs, firmware, and / or program logic that custom-tailor the microprocessor and / or controller. According to some embodiments, portions of the techniques disclosed herein are performed by the controller in response to execution of one or more sequential instructions contained in a memory. Such instructions may be loaded into the memory from another storage medium, such as a memory device. Execution of the sequences of instructions contained in the memory causes the processor or controller to perform the process steps described herein. In alternative embodiments, hardwired circuitry may be used in place of or in combination with software instructions.

[0052] Furthermore, the various illustrative logic blocks and modules described in connection with the embodiments disclosed herein may be implemented or executed by a machine designed to perform the functions described herein, such as a processor device, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. The processor device may be a microprocessor, but alternatively, the processor device may be a controller, microcontroller, or state machine, combinations thereof, etc. The processor device may comprise electrical circuitry configured to process computer-executable instructions. In another embodiment, the processor device comprises an FPGA or other programmable device that performs logical operations without processing computer-executable instructions. The processor device may be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration. While described herein primarily with respect to digital technology, a processor unit may comprise primarily analog components. For example, some or all of the technology described herein may be implemented with analog circuitry or mixed analog and digital circuitry.

[0053] Unless the context clearly requires otherwise, throughout this specification and claims, terms such as "comprises," "includes," "includes," and the like are intended to be inclusive, rather than exclusive or exhaustive, meaning "including, but not limited to." Additionally, the terms "coupled" or "connected," as generally used herein, refer to two or more elements, either directly connected or connected via one or more intermediate elements. Furthermore, the terms "herein," "above," "below," and similar terms, when used in this application, refer to this application as a whole, not to specific portions of this application. Where the context permits, words using singular or plural numbers herein can also include the respective plural or singular numbers. The word "or" in reference to a list containing two or more items is intended to encompass any item in the list, all items in the list, and any combination of items in the list. All numerical values ​​provided herein are intended to encompass similar values ​​within the limits of measurement error.

[0054] While the present disclosure includes specific embodiments and examples, those skilled in the art will understand that the scope of the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and / or applications, as well as obvious modifications and equivalents thereof. Moreover, while several variations of the embodiments have been shown and described in detail, other modifications will be readily apparent to those skilled in the art based on this disclosure. It is also intended that various combinations or subcombinations of specific features and aspects of the embodiments be made and still fall within the scope of the present disclosure. It should also be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another to form embodiments of various aspects. Any methods disclosed herein need not be performed in the order described. Therefore, it is not intended that the scope of the present disclosure be limited to the specific embodiments described above.

[0055] Conditional expressions such as "can," "could," "might," or "may," unless otherwise specified or understood otherwise by the context in which they are used, are generally intended to indicate that certain features, elements, and / or steps are included in one embodiment, but may not be included in other embodiments. Thus, such conditional expressions are generally not intended to imply that the features, elements, and / or steps are in any way required by one or more embodiments, or that one or more embodiments necessarily include logic for determining whether those features, elements, and / or steps are included or performed in a particular embodiment, with or without user input or prompting. Headings used herein are for the convenience of the reader and are not intended to limit the scope.

[0056] Furthermore, the devices, systems, and methods described herein are susceptible to various modifications and alternative forms, specific examples of which are shown in the drawings and described in detail herein. However, it should be understood that the disclosure is not limited to the particular forms or methods disclosed, but rather includes all modifications, equivalents, and alternatives falling within the spirit and scope of the various embodiments described. Furthermore, disclosure herein of particular features, aspects, methods, properties, qualities, attributes, elements, etc., associated with an example or embodiment can be used in all other examples or embodiments disclosed herein. The methods disclosed herein need not be performed in the order described. While the methods disclosed herein may include specific acts performed by a practitioner, these methods may also include, explicitly or implicitly, the direction of those acts by a third party.

[0057] Additionally, ranges disclosed herein encompass all overlaps, subranges, and combinations thereof. Phrases such as "up to," "at least," "greater than," "less than," and "between" may be inclusive of the stated numerical value. Numerical values ​​preceded by terms such as "about" or "approximately" are inclusive of the stated numerical value and should be interpreted accordingly (e.g., as precisely as reasonably possible under the circumstances, e.g., ±5%, ±10%, ±15%, etc.). For example, "about 3.5 mm" includes "3.5 mm." Phrases preceded by terms such as "substantially" are inclusive of the stated phrase and should be interpreted accordingly (e.g., as precisely as reasonably possible under the circumstances). For example, "substantially constant" includes "constant." Unless otherwise specified, all measurements are conducted under standard conditions, including ambient temperature and pressure.

Claims

1. A mobile robot, a drive system configured to move the mobile robot; and an environmental sensor configured to recognize one or more objects in an environment surrounding the mobile robot; a safety shutdown system; a safety shutdown avoidance system; The safety shutdown system includes: determining a safety zone having a size based at least in part on a velocity of the mobile robot; determining whether an object recognized by the environmental sensor is within the safety zone; configured to activate an emergency brake to stop the mobile robot in response to determining that an object is within the safety zone; The safe shutdown avoidance system includes: acquiring trajectory information regarding a planned travel path of the mobile robot; Recognizes objects outside the current safety zone, determining, based at least in part on the trajectory information, that the recognized object may enter within a future safety zone that is predicted to cause a safe shutdown event; the mobile robot being configured to control the drive system to decelerate the mobile robot and reduce the size of the safety zone to avoid the safety stop event.

2. 10. The mobile robot of claim 1, wherein the safety stop system is hardware based and the safety stop avoidance system is software based.

3. 10. The mobile robot of claim 1, wherein the size of the safety zone is based at least in part on a user-adjustable parameter, and the size of the predicted future safety zone is also based at least in part on the user-adjustable parameter.

4. It also has a navigation system, The mobile robot of claim 1 , wherein the safety stop system, the safety stop avoidance system, and the navigation system operate in parallel as separate modules.

5. It also has a navigation system, 10. The mobile robot of claim 1, wherein the navigation system is configured to modify the planned travel trajectory of the mobile robot based at least in part on a notification that the safety stop avoidance system has caused the mobile robot to slow down.

6. A mobile robot, a drive system configured to move the mobile robot; and a sensor configured to recognize one or more objects in the vicinity of the mobile robot; a safety system configured to stop the mobile robot when an object is detected within a safety zone having a size based at least in part on a speed of the mobile robot; a clearance system; The clearance system comprises: Recognizing an object using the sensor; acquiring trajectory information regarding a planned travel path of the mobile robot; determining a first future safety zone having a first size corresponding to the first velocity based at least in part on the trajectory information including the first velocity; determining that the recognized object is within the first future safety zone; determining a second future safety zone having a second size corresponding to a second velocity, the second size being smaller than the first size such that the recognized object is located outside the second future safety zone; The mobile robot modifies the trajectory information to use the second velocity.

7. 7. The mobile robot of claim 6, wherein the second velocity is less than the first velocity.

8. The mobile robot of claim 6 , wherein the sensor comprises a laser scanner.

9. 7. The mobile robot of claim 6, wherein the clearance system is configured to determine the first future safety zone to have the same size as the first size the safety zone has for the first velocity.

10. The mobile robot of claim 6 , wherein the safety system and the clearance system operate simultaneously and in parallel.

11. A mobile robot, a drive system configured to move the mobile robot; and an environmental sensor configured to recognize one or more objects in an environment surrounding the mobile robot; a safety system configured to perform a safety stop when an object is detected within an active safety zone of the mobile robot; a navigation system; The navigation system generating trajectory information based on the position, a target position, and one or more objects located in the environment, the trajectory information including a route from the position to the target position and one or more velocities along the route; determining one or more predicted safety zones based on the trajectory information; determining that the recognized object will fall within one of the one or more predicted safety zones; and adjusting the trajectory information to generate corrected trajectory information that places the recognized object outside the one or more predicted safety zones.

12. 12. The mobile robot of claim 11, wherein the size of the predicted safety zone is based at least in part on the speed of the mobile robot.

13. 13. The mobile robot of claim 12, wherein the navigation system is configured to adjust the trajectory information by reducing the speed of the mobile robot.

14. 12. The mobile robot of claim 11, wherein the navigation system is configured to adjust the trajectory information by altering the route of the mobile robot.

15. 12. The mobile robot of claim 11, wherein the navigation system is configured to determine a plurality of predicted safety zones based on the trajectory information and compare the position of the recognized object to the plurality of predicted safety zones.

16. a safety system configured to detect a safety event and to take a safety action in response to the detected safety event; a clearance system configured to predict future safety events and take action to avoid the predicted future safety events.

17. 17. The robot of claim 16, wherein the safety system is configured to stop the robot when an object is recognized inside a safety zone.

18. 18. The robot of claim 17, wherein the clearance system is configured to slow down the robot when an object is identified outside the safety zone and inside the predicted future safety zone.

19. 20. The robot of claim 18, wherein the size of the safety zone and the size of the predicted future safety zone vary based at least in part on a speed of the robot.

20. 20. The robot of claim 19, wherein the clearance system is configured to determine a reduced speed that allows the object to remain outside the safety zone and to decelerate the robot to the reduced speed.

Images