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EP-4741111-A1 - METHOD FOR SAFELY FEEDING LOADS TO A ROBOT

EP4741111A1EP 4741111 A1EP4741111 A1EP 4741111A1EP-4741111-A1

Abstract

To safely feed loads (200) to a robot (110), a barrier (120) with a passage opening (121), and a conveyor belt (130) are provided. A radar system (140) is configured to detect moving targets in three distinct detection regions (142a, 142b, 142c) above the conveyor belt (130), including a first region (142a) which occupies the passage opening (121), a third region (142c) proximal to the robot (110), and a second intermediate region (142b). In a sequence of entry steps, a load (200) advancing in the first and second regions (142a, 142b) is monitored until a verification step is initiated. In the verification step, the conveyor belt (130) remains still, and it is verified that there are no humans between the robot (110) and the barrier (120). In the entry and verification steps, the detection of a moving target in the third region (142c) determines the deactivation of the robot (110), In a delivery step, the conveyor belt (130) transports the load (200) towards the robot (110), and the detection of moving targets in the third region (142c) does not determine the deactivation of the robot (110).

Inventors

  • Muzaka, Alban

Assignees

  • Inxpect S.p.A.

Dates

Publication Date
20260513
Application Date
20251106

Claims (9)

  1. A method for safely feeding loads (200) to a robot (110), comprising: - providing a robot (110); - providing a barrier (120) spaced from the robot (110), having a passage opening (121), - providing a conveyor belt (130) operable to transport loads (200) from the passage opening (121) to the robot (110), - providing a radar system (140) configured to detect moving targets in three distinct detection regions (142a, 142b, 142c) above the conveyor belt (130), including a first region (142a) which occupies the passage opening (121), a third region (142c) proximal to the robot (110), and a second region (142b) between the first and third regions (142b, 142c), - controlling the operation of the conveyor belt (130) and the robot (110) as a function of the detection of targets by the radar system (140) in the first, second, and third regions (142c), such that: - in a sequence of entry steps and in a verification step, following the sequence of entry steps, the detection of a moving target in the third region (142c) determines the deactivation of the robot (110), - in the sequence of entry steps, a load (200) is detected as a moving target in the first and second regions (142a, 142b), until a predetermined intermediate condition is reached, identified by such a combination of target detections in the first, second and third regions (142a, 142b, 142c) as to determine the start of the verification step, wherein the intermediate condition is a condition in which the presence of at least one moving target is detected in the second region (142b), and in which the absence of moving targets is detected in the first and third regions (142a, 142c), - in the verification step, starting from the intermediate condition, the conveyor belt (130) is controlled to remain still, and while the conveyor belt (130) is still it is verified whether a predetermined safety condition is fulfilled, identified by a combination of target detections in the first, second and third regions (142a, 142b, 142c) indicative of the absence of humans between the robot (110) and the barrier (120), wherein the safety condition is a condition in which the absence of moving targets is detected in the first, second, and third regions (142a, 142b, 142c), - in a delivery step, following the verification step, starting from the safety condition, the conveyor belt (130) is controlled to advance and transport the load (200) towards the robot (110), and the detection of moving targets in the third region (142c) does not determine the deactivation of the robot (110).
  2. Method according to claim 1, wherein the radar system (140) is configured to detect moving targets in the first, second, and third regions (142a, 142b, 142c), and to not detect stationary targets.
  3. Method according to any one of claims 1 to 2, wherein, in the verification step and in the delivery step, the detection of moving targets in the first region (142a) determines the deactivation of the robot (110).
  4. Method according to any one of claims 1 to 3, wherein: - in the sequence of entry steps, the conveyor belt (130) is controlled to advance and transport the load (200) towards the robot (110), and - in the verification step, the conveyor belt (130) is controlled to stop before verifying whether the safety condition is fulfilled.
  5. Method according to any one of claims 1 to 4, wherein the first and third regions (142a, 142b, 142c) are barrier-shaped regions (120), and the second region (142b) is a region with greater dimensions than the first and third regions (142a, 142c) in an advancement direction (X-X) of the conveyor belt (130), wherein the dimensions of the second region (142b) in the advancement direction are sufficient to entirely contain a predetermined load (200), which preferably comprises a pallet.
  6. Method according to any one of claims 1 to 5, wherein the sequence of entry steps comprises a first step in which a moving target is detected only in the first region (142a), and a second step in which moving targets are detected in both the first and second regions (142a, 142b), the intermediate condition following the second step.
  7. The method according to any one of claims 1 to 6, wherein the radar system (140) is identified by a single radar device (141) configured to simultaneously monitor the first, second, and third regions (142a, 142b, 142c), preferably wherein the first, second, and third regions (142c) are parallelepiped-shaped regions, and the radar device (141) is a volumetric radar device configured to detect the target position in a three spatial coordinate system.
  8. Control system for feeding loads (200) to a robot (110), comprising: - a radar system (140), configured to detect moving targets in three distinct detection regions (142a, 142b, 142c) above a conveyor belt (130), including a first region (142a) sized to occupy a passage opening (121) of a barrier (120), a third region (142c) sized to be located proximal to a robot (110), and a second region (142b) between the first and third regions (142c), wherein the radar system (140) is further configured to generate a status signal indicating the presence and absence of moving targets detected in each of the first, second, and third regions (142a, 142b, 142c), - a processing system (150), having a first communication channel for receiving the status signal from the radar system (140), a second communication channel for controlling a conveyor belt (130), and a third communication channel for controlling a robot (110), wherein the processing system is configured to control the operation of the conveyor belt (130) and the robot (110) as a function of the status signal, such that: - in a sequence of entry steps and in a verification step, following the sequence of entry steps, the detection of a moving target in the third region (142c) determines the deactivation of the robot (110), - in the sequence of entry steps, the status signal is monitored with reference to the presence of moving targets in the first and second regions (142a, 142b), until a predetermined intermediate condition is reached, identified by such a condition of the status signal as to determine the start of the verification step, - in the verification step, starting from the intermediate condition, the conveyor belt (130) is controlled to stop and remain still, until a predetermined safety condition is reached, identified by a condition of the status signal indicative of the absence of humans between the robot (110) and the barrier (120), - in a delivery step, following the verification step, starting from the safety condition, the conveyor belt (130) is controlled to advance and transport the load (200) towards the robot (110), and the detection of moving targets in the third region (142c) does not determine the deactivation of the robot (110).
  9. System (100) for feeding loads (200) to a robot (110), comprising: - a robot (110), - a barrier (120) spaced from the robot (110), having a passage opening (121), - a conveyor belt (130) operable to transport loads (200) from the passage opening (121) to the robot (110), and - the control system of claim 8.

Description

Technical field The present invention is developed in the technical field of safety in automated work environments with hazards for humans. Background of the invention In industrial production or processing sites, the presence of robotic machinery is common, therefore with automatically moving parts, potentially dangerous for a person who is too close to the robot. In some applications, a robot must perform a series of repetitive operations on particular products, which are loaded onto pallets. In these cases, a first safety measure for people is the presence of a physical barrier to hinder the access of staff to the robot while it is operating, but still allowing the passage of the loads to be processed. Since people cannot reach the robot, the loads on the pallets are transported to the robot by a conveyor belt that passes through an opening in the barrier. However, it can also happen that a person crosses the opening of the barrier and approaches the robot, for example to verify unexpected conditions in the operation of the robot. When this occurs, it is critical that safety procedures are followed, such as deactivating the robot when the operator reaches a certain distance. Automated systems for controlling the deactivation of a robot when hazardous conditions occur are known in the art. Thanks to this automation, the risk of human error is avoided. Problems of the background art To ensure maximum safety, and not risk the robot remaining active even in dangerous conditions, many automated systems control the deactivation of the robot frequently, even in non-hazardous conditions during the normal operation of the robot and the conveyor belt. This causes processing delays, and sometimes requires human intervention to reactivate the robot. To avoid these problems, automated safety systems are desired which intervene selectively when it is actually required, distinguishing hazardous situations from normal safe operations, such as the movement of the load on the conveyor belt. Summary of the invention The object of the present invention is to solve the aforementioned problems of the prior art, with a very selective detection of the hazardous conditions that allows the continuous operation of the robot, as long as the hazard does not manifest. These and other objects are achieved by a method for safely feeding loads to a robot, a control system for feeding loads to a robot, and a system for feeding loads to a robot, according to any of the appended claims. According to the invention, a radar system detects moving targets in three distinct detection regions above the conveyor belt, including a first region occupying the passage opening of the physical barrier protecting the robot, a third region proximal to the robot, and a second region between the first and third regions. The operation of the conveyor belt and the robot are controlled as a function of the target detection by the radar system in the first, second, and third regions. This control means that in a sequence of entry steps and in a verification step, following the sequence of entry steps, the detection of a moving target in the third region determines the deactivation of the robot. In the sequence of entry steps, a load is monitored as it passes through the first and second regions, until a predetermined intermediate condition is reached, identified by a combination of target detections in the first, second and third regions such as to determine the start of the verification step. In the verification step, starting from the intermediate condition, the conveyor belt is controlled to remain still, until reaching a predetermined safety condition, identified by a combination of target detections in the first, second and third regions indicative of the absence of humans between the robot and the barrier. In a delivery step, following the verification step, starting from the safety condition, the conveyor belt is controlled to advance and transport the load towards the robot, and the detection of moving targets in the third region does not determine the deactivation of the robot. Advantageously, this control maintains a general safeguard, whereby the third region can be passed through by a target without deactivating the robot only when it is reasonably certain that target is a load, and not a person. Advantageously, the verification that no people are present occurs automatically by stopping the conveyor belt, and verifying that in that moment everything remains stationary. Advantageously, when it is verified that there are no people present, the load has already passed the first region. Therefore, from that moment on, the restart of the conveyor belt will no longer bring the load to pass through the first region. Any detection of a target in the first region will therefore necessarily be caused by an unforeseen event, potentially the passage of a person, and consequently the robot can be deactivated. Further features and advantages of the invention wi