Safety control apparatus for tool changing device of robotic arm

Abstract

To provide a safety control apparatus for a tool changing device of a robotic arm.SOLUTION: A safety control apparatus is configured to allow decoupling or coupling between a robotic arm (5) and a tool (6) safely. The safety control apparatus comprises: a first module (101) associated with the robotic arm; a second module (102) associated with the tool; and means (103) associated with a tool parking station (30) adapted to prevent or allow creation of a safety signal in the second module. The second module is configured to wirelessly transmit at least one safety signal to the first module. The first module is configured to allow the decoupling or the coupling between the robotic arm and the tool in response to reception of the at least one safety signal.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the field of robotics and industrial automation, and more particularly to a tool changing device coupled to a robot arm. The present invention has been developed in particular with reference to a safety control device for a tool changing device of a robot arm. [Background technology]

[0002] A robot island is known in the art to be a collection of one or more industrial robots, i.e. machines equipped with manipulators and automatically controlled and programmable to perform three or more axes of motion, for a variety of applications.

[0003] Their use is becoming more and more widespread in various industrial applications, from logistics to painting, assembly, coating, welding, etc. Therefore, within these islands, the need arises for robots and manipulators to have the possibility to use several tools to carry out different functions, i.e. for them to be equipped with tool changing devices.

[0004] The tool changing system preferably comprises: Robots or manipulators (automatic or semi-automatic) a robot or machine adaptor that is mechanically connected to the end of a robot arm or manipulator; A tool adapter for mechanically connecting to a tool (for machining, gripping, etc.); a parking station capable of safely receiving the tool adapter and thus accommodating the tool and ensuring that it is mechanically held without risk of falling; Equipped with.

[0005] The integration and installation of industrial robots and robotic equipment into production lines carries inherent risks. International standards already recognize these risks and prescribe a set of minimum safety requirements that should be adopted by all parties involved in robotic systems (manufacturers, suppliers, integrators and users) to ensure a safe working environment.

[0006] The Owner has carried out numerous experiments and research and development activities to find various solutions (mechanical, pneumatic, electrical) for tool changers in automation applications that ensure that the tool itself cannot be detached from the robot arm unless one or more safety conditions are met, including the consideration that the detachment directive cannot be applied to the tool changer unless it meets the necessary safety conditions.

[0007] SUMMARY OF THE PRESENT EMBODIMENT In view of the above, it is an object of the present invention to provide a solution to such needs. In particular, it is an object of the present invention to provide a safety control system for a tool changing device of a robot arm that is more efficient and reliable than known systems.

[0008] More specifically, it is an object of the present invention to provide a safety control for a tool changing device of a robot arm that is applicable to all commercially available tool changer sizes.

[0009] This and other objects are achieved by embodiments of the invention which comprise the technical features defined in the main claim. The dependent claims outline preferred and / or particularly advantageous aspects of the invention. Summary of the Invention

[0010] In particular, the present invention makes available a safety control device for a tool changing device of a robot arm, configured to safely decouple or couple the robot arm and the tool, comprising a first module associated with the robot arm, a second module associated with the tool, and means associated with a tool parking station for inhibiting or allowing generation of at least one safety signal in the second module, the second module configured to wirelessly transmit the at least one safety signal to the first module, and the first module configured to allow decoupling or coupling between the robot arm and the tool in response to receiving the at least one safety signal. This eliminates the wear and tear and maintenance required for coupling means of previously known and used systems.

[0011] Preferably, at least the second module comprises data storage means and at least one digital port taking an initial state, means associated with the tool parking station change the initial state of the at least one digital port to a new state different from the initial state, the new state of the at least one digital port being stored in the storage means, and the at least one safety signal comprising the new state of the at least one digital port.

[0012] Preferably, said at least one security signal comprises a security code in the form of a numeric or alphanumeric string stored in said storage means.

[0013] Preferably, the storage means of the second module is configured to store at least one code having a progressive number assigned to the tool, and the at least one safety signal transmittable wirelessly from the second module to the first module comprises the at least one code having a progressive number assigned to the tool.

[0014] This provides an additional code that allows one tool to be distinguished from another when the number of tools is at least two, particularly when the number of tools to be exchanged is significant, e.g. when the number of tools coupled to a robot is greater than one.

[0015] Preferably, said at least one code comprising a progressive number assigned to said tool is entered into said storage means by a user via an external communication module.

[0016] Preferably, the apparatus comprises a control circuit associated with said first module, said control circuit comprising a memory in which said at least one safety signal is stored, said control circuit being configured to perform an operation of verifying a correspondence between said at least one safety signal originating from said second module and received from said first module and said at least one safety signal present in said memory of said control circuit, and configured, after performing said verify operation, to allow decoupling or coupling between the robot arm and the tool if said verify operation is positive. Thus, there is a safety control over the safety signal received from the second module.

[0017] Preferably, the means associated with the parking station comprise a magnetic actuator and the second module comprises a magnetic sensor actuable by said magnetic actuator.

[0018] Alternatively, the means associated with the parking station comprises an electrical circuit, and the at least one digital port of the second module is electrically connectable to the electrical circuit associated with the parking station.

[0019] Preferably, the second module is configured, when connected to the parking station, to power the electrical circuitry associated with the parking station.

[0020] Preferably, the magnetic sensor comprises at least one electrical switch commanded by the magnetic actuator, and the at least one digital port of the second module is electrically connected to the at least one electrical switch of the magnetic sensor, the at least one digital port being configured to change state when the magnetic sensor is actuated by the magnetic actuator associated with the parking station.

[0021] Preferably, the second module is configured to power the electrical contacts of the magnetic sensor.

[0022] Alternatively, the means associated with the parking station comprises an electrical circuit, and the second module comprises at least one microprocessor electrically connectable to the electrical circuit associated with the parking station, and the second module is configured to power the microprocessor and the electrical circuit associated with the parking station when connected to the parking station.

[0023] Preferably, said first module comprises an RFID reader and said second module comprises at least one RFID chip.

[0024] This reduces wear and tear on the power supply components used and eliminates the need for maintenance.

[0025] The present invention also provides a tool changing device for a robot arm, comprising a safety control device as described above.

[0026] Preferably, the tool changing device comprises a robot adaptor connected to the robot arm and a tool adaptor connected to the tool, the first module being disposed in the robot adaptor and the second module being disposed in the tool adaptor. [Brief description of the drawings]

[0027] Further features and advantages of the invention will become more apparent on reading the following description, given by way of non-limiting example with the aid of the attached drawings, in which:

[0028] [Figure 1] 1 is a schematic side view of a tool changing device of a robot arm equipped with a safety control device according to the present invention; [Diagram 2] FIG. 2 is a schematic diagram of a safety controller for the tool changing device of FIG. 1 according to an embodiment of the present invention. [Figure 3a] 13A to 13C are diagrams showing various possible configurations of the second module of a safety control device according to a second embodiment of the present invention and its modified example. [Figure 3b] 13A to 13C are diagrams showing various possible configurations of the second module of a safety control device according to a second embodiment of the present invention and its modified example. [Figure 3c] 13A to 13C are diagrams showing various possible configurations of the second module of a safety control device according to a second embodiment of the present invention and its modified example. [Figure 3d] 13A to 13C are diagrams showing various possible configurations of the second module of a safety control device according to a second embodiment of the present invention and its modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] 1, a tool changing device, which can be actuated, for example, by compressed air, is generally indicated by the reference number 10 and comprises a robot adapter 1, which is in particular connected to a robot arm 5, and preferably a tool adapter 2, which is in particular connected to a tool 6 and a support 7, which is for example a plate or a shelf for storing the tool 6 in a parking station 30. The robot arm 5 is a robotic arm or manipulator, which can be either automatic or programmable.

[0030] Generally, the tool changing device is preferably provided with a coupling unit by which the robot adaptor can be rigidly coupled to the tool adaptor.

[0031] This coupling unit can be located on the robot adaptor or on the tool adaptor, preferably, but not necessarily, on the robot adaptor to avoid increasing the cost of tool adaptors which are obviously more numerous in the application.

[0032] The coupling unit may comprise an active part and a passive part. The active part has at least one moving element for coupling with the passive part, thus forming a mechanically strong coupling. Typically, a plurality of such moving elements are provided. The active part can be arranged on the robot adaptor and the passive part on the tool adaptor. Alternatively, the passive part is arranged on the robot adaptor and the active part on the tool adaptor. If an active part and a passive part are provided, the adaptor carrying the coupling unit should be the active part, i.e. the one with the moving part.

[0033] The coupling unit has a default state where the device hooks itself up and is kept in that state by the coupling forces.

[0034] The coupling unit can transition from the default state to the decoupled state only when a decoupling force is applied. It can be envisaged that the decoupling energy consists of pneumatic, hydraulic and / or electromagnetic energy, in particular electrical energy, so that the decoupling force comprises a pneumatic force and / or a hydraulic force and / or an electromagnetic force, in particular an electrical force.

[0035] When pneumatic energy is used, the coupling unit can be brought out of the default state by a supply of compressed air, which allows the use of techniques often used in the field of industrial robotics and automation, which can be easily sourced and utilized to reliably and quickly switch the coupling unit from the default state to the decoupled state.

[0036] In the case of pneumatic energy, an air pressure sensor is usually arranged in a particularly preferred manner between the supply entry point and the coupling unit to control the supply of compressed air. If this compressed air sensor detects a drop in the supply of compressed air or a drop in its pressure, which would indicate a lack of coupling force, it can output a warning signal so that appropriate measures can be taken. If other forms of energy are used, the sensor may be an electromagnetic and / or hydraulic sensor for monitoring the supply of energy to the coupling unit.

[0037] It can further be envisaged that the binding energy and force and / or the closing energy and force are caused or mediated by a spring, so that the binding unit is held in the default state by a mechanically acting elastic force, the binding force preferably resulting from a combination of a spring with compressed air, hydraulic or electromagnetic forces.

[0038] Other mechanical retention systems, such as special profiles of the mechanical coupling elements (eg having a mechanically irreversible profile) may be alternatives or additions to the springs.

[0039] Since two or more different mechanisms are provided to hold the coupling unit in the coupled position, the coupling position is reliably held even in the event of a component failure, such as a broken spring, loss of compressed air, etc. Of course, the coupling unit can alternatively be held in the default state by only spring force, only compressed air, only hydraulic force, only electromagnetic force, or only mechanical elements.

[0040] The cleavage energy is usually the same type of energy as the bond energy, but alternatively, the two energies may be different types.

[0041] The safety conditions required to activate the tool changer disconnect are, for example: If the tool changer is connected to a tool (i.e. the robot adapter and the tool adapter are connected) and it is in the parking station, When not in the parking station (i.e. moving) and the tool adapter fixed to the tool itself is not coupled to the robot adapter (the robot adapter is not engaged), etc. It could be.

[0042] Typically the tool changer disengage command is generated by an electronic controller, usually that of the robot or machine.

[0043] Regardless of the particular controller, the generation and transmission of the disconnect command is typically carefully controlled to prevent inadvertent generation and asynchronous disconnection of the tool from the robot or manipulator arm.

[0044] However, due to risks such as software malfunctions and human error, it is desirable to incorporate an interlock or safety control into the disconnection circuit.

[0045] This has resulted in the requirement that such automation equipment be equipped with appropriate safety control systems, including pneumatic or electrical controls or other types of controls, to ensure that the release of the hookless tool only occurs at designated locations or under specific controlled conditions and that such release does not create a hazardous situation.

[0046] Various types of safety control systems for tool changers applied in automation are known in the art.

[0047] The first type is where decoupling energy is supplied from the robot to the tool changer coupling units to actuate the relative decoupling or decoupling of the tool changer coupling units.

[0048] In this case, a pneumatic and / or electrical control system is typically provided which allows the supply of this energy only under the above-defined safe conditions or, rather, does not allow the supply of this energy under unsafe conditions, which control system must detect the coupling position of the tool adapter relative to the robot adapter and / or the correct installation position of the tool adapter in the parking station.

[0049] This first type of tool changer safety control system, although very reliable and widely proven in a variety of applications, is rather expensive and difficult to apply to small capacity and compact tool changers.

[0050] Additionally, the use of pneumatic, hydraulic or electrical coupling means in contact with each other creates wear and requires regular maintenance to ensure production efficiency.

[0051] A second type of tool changer control system supplies decoupling energy from the parking station to the tool adapter by a supplying device which supplies decoupling energy to the tool adapter.

[0052] The delivery device has a default state in which it is held closed (i.e., unable to be energized) by a closing force After the tool adapter is received in the parking station against the closing force, the delivery device is actuated to an open position.

[0053] Since the supply device is now in the open position, the decoupling energy is transmitted to the coupling unit via the parking station, the supply device and the coupling means that directly or indirectly connects the parking station to the adapter carrying the coupling unit.

[0054] This ensures that when both adapters (robot and tool) are located in the parking station and the robot adapter is coupled to the tool adapter, the decoupling takes place in safe conditions.

[0055] When the coupling unit is located on the robot adaptor, which is a more common solution in the art due to its low cost, energy is transferred from the tool adaptor to the robot adaptor via pneumatic or hydraulic or electrical coupling means.

[0056] If the robot adaptor is not coupled to the tool adaptor and has to be coupled at the parking station to pick up a tool, the coupling unit must be unlocked before the robot adaptor can engage with the tool adaptor, which results in the need to mechanically extend the energy supply coupling means (e.g. valves) from the tool adaptor to the robot adaptor. This is In this case, the connection between the robot adaptor and the tool adaptor is detected so that the expansion function is not activated, - Detect the minimum distance required to feed the robot adapter, · It implies the need for precise mechanical guiding of the approach of the robot adaptor to the tool adaptor.

[0057] This may require stopping the robot or manipulator motion moving the robot adaptor towards the tool adaptor to allow mechanical engagement of the energy coupling means, resulting in longer coupling times.

[0058] Finally, this second type of control does not improve the mechanical wear and necessary maintenance of the coupling means between the robot and the tool adapter, but on the contrary increases the risks, since these means must be coupled at a certain distance.

[0059] The robot adaptor 1 comprises a pneumatic cylinder 17, preferably but not exclusively a double-acting pneumatic cylinder consisting of a cylinder or pneumatic chamber and a piston 16 slidably arranged in the cylinder. The piston 16 comprises a shaft 119 connected to an engagement element or coupling unit 120, specifically one end of which engages with the tool adaptor 2. The pneumatic cylinder 17 specifically actuates a coupling / decoupling mechanism of the robot arm 5, preferably the robot adaptor 1, with the tool 6, preferably the tool adaptor 2. The coupling unit 120, better called a coupling / decoupling unit since it also allows the decoupling of the tool 2, preferably the tool adaptor 2, is preferably arranged on the robot adaptor 1 and preferably comprises at least three movable coupling elements (not shown) which help to hold the tool adaptor 2 coupled to the robot adaptor 1 by springs, possibly also by a coupling profile that ensures irreversibility in the coupled position.

[0060] Of course, the tool changer may be manually, electrically, hydraulically or otherwise actuated without departing from the scope of the present invention.

[0061] In the active state of the tool changer, it is necessary to disconnect the tool 6 from the robot arm 5 and to send a command signal to a pneumatic cylinder 17 of the robot arm 5, preferably the robot adapter 1, which acts on a coupling / decoupling mechanism with the tool 6, preferably the tool adapter 2. In particular, it is necessary to send a command signal to one, but preferably several pneumatically actuated valves V1, which are arranged on the robot arm 5 or integral with the robot adapter 1 or in a control module installed in the robot adapter 1 itself, and which act on the pneumatic cylinder 17 which acts on a coupling / decoupling unit 120. As an alternative to pneumatically actuated valves, hydraulic or electric actuating devices can be envisaged which are arranged on the robot arm 5 or in association with the robot adapter 1.

[0062] In the present invention, a command signal for disconnecting the tool changer can be sent to the pneumatically operated valve V1 only when the tool adapter 2 is placed in the parking station 30 and at the same time the robot adapter 1 is in the vicinity of the tool adapter 2, i.e., at a distance D1 of, for example, 2 mm to 60 mm from the tool adapter 2.

[0063] In other positions of the tool adapter 2, no disconnect or decoupling command signal can be transmitted to the pneumatically operated valve V1.

[0064] This operation is made possible by an electronic safety controller 100 comprising a first module 101 associated with the robot arm 5 and preferably arranged on the robot adapter 1, a second module 102 associated with the tool 6 and preferably arranged on the tool adapter 2, and means 103 associated with the parking station 30. Said safety controller 100 is thus configured to allow or inhibit an unsafe uncoupling of the tool 6 from the robot arm 5, in particular of the tool adapter 2 from the robot adapter 1, or to allow a coupling or connection between the tool 6 and the robot arm 5. Said safety controller 100 is activated when the robot arm 5, in particular the robot adapter 1, receives a decoupling or coupling command from a control unit 150 of the robot arm 5 or of the manipulator, for example the control unit 150 sends a signal Ssg, which is a control signal, to the first module 101 for the activation of the safety controller 100.

[0065] The first module 101 and the second module 102 exchange data with each other wirelessly. Preferably, the communication is radio frequency, in particular HF or UHF communication, as is most preferred in industrial environments.

[0066] The means 103 of the first embodiment of the invention shown in FIG. 2 are adapted to allow or inhibit the generation of at least one safety signal S in the second module 102 .

[0067] The second module 102, as better shown in FIG. 2 , which shows a safety control device for a tool changing device of a robot arm according to an embodiment of the present invention, emits at least one safety signal S to the first module 101 upon request of the first module 101 to enable decoupling of the tool 6 from the robot arm 5 or coupling between the tool 6 and the robot arm 5, specifically coupling from the robot adapter 1.

[0068] Preferably, a first module 101 powered by the robot transmits energy wirelessly, preferably at radio frequency, to a second module 102 associated with the tool 6 to power the module 102 .

[0069] This solution eliminates the wear and tear on the coupling means of previously known and used systems, and also eliminates the need for maintenance.

[0070] Preferably, the first module 101 comprises a reading device 104, for example an RFID reader, and a specially designed antenna 105.

[0071] The reading device 104 is preferably connected to a control circuit 106 comprising at least one data processing unit 107, for example a microprocessor 107, which manages the reading device 104 and processes the signals received from the reading device itself. The control circuit 106 also comprises a non-volatile memory 1070, for example an EEPROM memory, associated to the processing unit 107, preferably the memory 1070 being integrated in the microprocessor 107. Preferably, in order to meet international safety standards in the field of robotics, such as ISO / IEC 10218-2 for robot integration, the control circuit 106 comprises at least two independent microprocessors with a voting system 1002 (1:2 1002 voting) to improve the reliability of the safety control. Different microprocessor solutions are also possible (for example a single chip with two CPUs or FPGA), both two microprocessors being associated with their own memories. The two microprocessors monitor each other and compare their processing results to allow the activation of the tool changer, i.e. the uncoupling of the tool 6 from the robot arm 5. The control circuit 106 belongs to the first module 101 and may be separate from the control unit 150 or may be integrated in the control unit 150 so as to realise a single control logic unit 106,150.

[0072] The second module 102 associated to the tool 6 preferably comprises a chip 109, for example an RFID chip, provided with a non-volatile memory 110, for example of the EEPROM type, i.e. a memory arranged to store data which must be retained when the power supply is switched off. The memory 110 can be written to and erased by special procedures.

[0073] The second module comprises at least one digital port 1041, 1042 that assumes an initial state, the initial state being a LOW logic state or a HIGH logic state. Preferably, the at least one digital port 1041, 1042 is an input digital port. Means 103 associated with the tool parking station 30 are configured to change the initial state of said at least one digital port to a new state other than the initial state. The new state of said at least one digital port is stored in the memory 110 of the module 102. At least one safety signal S comprises the new state of said at least one digital port, and thus the means 103 are configured to create a safety signal S, since it allows the change of the state of the at least one digital port and the new state becomes part of the safety signal S.

[0074] The RFID chip 109 of the second module 102 preferably contains in the memory 110 a unique identification code UID consisting of a certain number of bits (for example 64 according to the RF ISO / IEC 15693 standard) constituting an identification code of the RFID chip. The safety signal S preferably contains the unique identification code UID.

[0075] Preferably, the memory 110 contains other identification data such as a byte of the RF ISO / IEC 15693 standard for identifying the dedicated application (AFI code or application family identifier) ​​and other data selected by the module manufacturer 102 with a freely selectable number of bits as required.

[0076] Specifically, for the tool changer control application, one or more numeric codes, each in the form of a number of bytes, are stored in memory 110, protected by read and write passwords, encrypted, and written to designated memory areas.

[0077] The safety signal S includes at least one safety code Saut in the form of a numeric or alphanumeric string of a certain number of bytes stored in the memory 110, preferably protected by a read and write password, preferably encrypted, and the safety code Saut is written into a designated memory area of ​​the memory 110.

[0078] The safety signal S preferably also includes the above-mentioned identification data, such as an AFI code or other numerical code, stored in memory 110 .

[0079] Preferably, the same numerical code present in memory 110 is also present in memory 1070 of processing unit 107, or in memories associated with the microprocessors if control circuit 106 comprises more than one microprocessor.

[0080] The code is transmitted redundantly by the device 102, preferably with a sequence of control bits for cyclic redundancy control (CRC) to avoid communication errors due to environmental electromagnetic interference.

[0081] The second module 102 comprises an antenna 111 arranged to transmit at least one safety signal S including at least one safety code Saut, the new state of at least one digital port 1041, 1042, preferably also a unique identification code UID and other codes contained in the memory 110. The antenna 111 is preferably an antenna laid on a suitable substrate and connected to the chip 109.

[0082] The chip 109 is connected to at least one magnetic sensor 112 with at least one electrical switch 113, which is actuated by a magnetic actuator 160 in the means 103. Preferably, the magnetic sensor 112 is connected to the chip 109 via a combination of a cable and a four-wire female / male connector 114. In particular, the magnetic sensor 112 is preferably selected to be of the lead type, which does not require a power source to indicate the presence of a magnetic actuator in the vicinity of the sensor.

[0083] According to a variation of this first embodiment of the invention, the magnetic actuator 160 can be encoded.

[0084] The reed magnetic sensor 112 is preferably disposed on a support 7 stably coupled to the tool adapter 2, and the support 7 is coupled to the parking station 30 for disposing the tool 6. The magnetic actuator 160 is disposed on the parking station 30 such that when the tool 6 is disposed on the parking station 30, the magnetic actuator 160 is aligned in front of the magnetic sensor 112 so that the magnetic sensor 112 can be activated. Specifically, the magnetic sensor 112 can be activated when the magnetic actuator 160 is within a predetermined distance D (a few millimeters, depending on the type of sensor, e.g., 2 mm or 3 mm) from the magnetic sensor 112.

[0085] Depending on the presence or absence of a tool 6, specifically a tool adapter 2, in the parking station 30, the magnetic sensor 112 allows or inhibits the generation of at least one safety signal S which is then transmitted to the first module 101, specifically the reading device 104.

[0086] When the robot arm 5, in particular the robot adapter 1, has to operate the disconnection or connection of the tool 6 with the tool 6, the control unit 150 of the robot arm 5 or manipulator (not shown) activates the first module 101, in particular the reader 104 of the first module, by command Ssg. Preferably, when the reader 104 is within a predefined distance D1 from the tool 6, in particular from the tool adapter 2, and from the second module 102, comprised for example between 2 mm and 60 mm, it transmits energy at radio frequency by means of the antenna 105 to the second module 102.

[0087] Only when the magnetic actuator 160 of the means 103 arranged in the parking station 30 is aligned in front of the magnetic sensor 112, specifically within a distance D therefrom, are the two switches 113 of the magnetic sensor 112 activated by the magnetic actuator 160 and a safety signal S is formed in the RFID chip 109.

[0088] When the reader 104 in the first module is activated, it interrogates the RFID chip 109 and reads the designated memory area.

[0089] The safety signal S is transmitted from the chip 109 of the second module 102 to the first module 101 via the antenna 111 so that it can be read by the reader 104 .

[0090] Preferably, the second module 102 transmits at least one safety signal S when the first module 101 is located at a distance equal to or smaller than a distance D1 from said second module.

[0091] Preferably, the reader 104 of the first module transmits the safety signal S, the safety code Saut, the new state of at least one digital port 1041, 1042, if they are present in the memory 110, the code UID and other numerical codes present, to at least one processing unit 107, performing an operation of verifying the match with the codes stored in at least one memory 1070, and if there is a match between the transmitted code and the codes stored in at least one memory 1070, i.e. if the verify operation is positive, the processing unit 107 of the first module 101 transmits an authorization signal Aut to an electronic, electromechanical or other type of valve actuation driver 500 (preferably belonging to the first module 101), which sends a command to a pneumatically actuated valve V1 arranged on the robot arm 5 or integral with the robot adapter 1, enabling the operation of disconnecting the tool 6 from the robot arm 5 or of coupling the robot arm 5 to the tool 6.

[0092] However, it is also possible for the first module 101 to send an authorization signal Aut to the driver 500 without performing a verification operation, i.e. upon arrival of the signal S to the first module 101, to enable an operation of disconnecting the tool 6 from the robot arm 5 or coupling the robot arm 5 to the tool 6.

[0093] Upon arrival of the authorization signal Aut, the valve actuation driver 500 sends a command Ssgaut to an air-operated valve V1 positioned on the robot arm 5 or integrally with the robot adapter 1, which in turn acts on the air cylinder 17 to detach or disconnect the tool 6 from the robot arm 5, in particular to detach or disconnect the robot adapter 1 from the tool adapter 2, or to couple the robot arm 5 with the tool 6.

[0094] As already mentioned above, it is also possible for the control circuit 106, which is normally separate from the control unit 150, not to be separate from the control unit 150 but to belong to the same unit 150, so that the robot arm 5 has a single logical control unit 150, 106.

[0095] Preferably, each microprocessor has a pair of numeric codes stored in its own dedicated memory area. Each microprocessor compares the data set read by the reader 104 with the data set stored in its memory, and accepts only if the data match, preferably checked with a checksum.

[0096] Preferably, the at least one processing unit 107 also stores the code UID of the chip 109 during the step of coupling the tool adapter 2 and compares it with the code UID read by the chip 109 when the processing unit 107 itself receives the signal Ssg, or with the code UID read upon decoupling, always preferably at periodic time intervals during the entire coupling time of the tool changer with the robot side and the tool side, thereby making it possible to avoid interference with other RFID chips present in the working environment.

[0097] Code from the AFI application family can also be used for this purpose.

[0098] If the first module 101 comprises two microprocessors 107, the control circuit 106 of the first module 101 only authorizes, via signal Aut, the operation of decoupling or coupling the tool 2 to the robot arm 5 if both microprocessors give their consent simultaneously (or within a reasonable time frame on the order of milliseconds).

[0099] If the tool adapter 2 is not properly positioned in the parking station 30, the magnetic sensor 112 is not activated by the magnetic actuator 160 and the switch 113 remains in the default position, not setting the second module 102 for generating the safety signal S.

[0100] When the tool adapter 2 is properly positioned in the parking station 30 while the robot arm 5 or manipulator is moving and the robot adapter 1 fixed at its tip is to be coupled to the tool adapter 2, the coupling / discoupling unit 120 must release the lock before the robot adapter 1 engages with the tool adapter 2.

[0101] The safety control system according to the present invention can perform this operation as soon as the robot adapter 1 is close enough to energize the antenna 111 of the module 102 .

[0102] The safety control device 100 for the tool changing device does not have any contact connecting means between the robot adapter 1 and the tool adapter 2, specifically between the first module 101 associated with the robot adapter 1 and the second module 102 associated with the tool adapter 2.

[0103] Furthermore, one or more codes can be read while the robot arm 5 or manipulator is approaching the robot adapter 1 to the tool adapter 2 at a slow speed, without having to stop and therefore without any delay in cycle time.

[0104] Depending on the size of the tool changer and therefore the distance at which the coupling unit of the robot adapter 1 must be unlocked before engaging the tool adapter 2, the antennas of both the reader 104 and the RFID chip 109 can have different areas with extensions proportional to the reading distance.

[0105] According to a further modification of the first embodiment of figures 1-2, the safety controller 100 can perform additional functions.

[0106] In applications where the number of tools to be exchanged is significant, for example when the number of tools coupled to a robot is greater than one, the need arises for the user to assign a code with a progressive number to the tool, in order to be able to distinguish it during the picking stage from the parking station (which is also numbered).This also avoids collisions in the work area, since each tool must move in the work cell according to a pre-set program, so that if a robot or manipulator picks up the wrong tool at one machining stage, in a trajectory designed for another tool, it may collide with a machine in the cell or create unforeseen risks.

[0107] A code PR with a progressive number must therefore be assigned to the tool by the user at the stage of initial programming of the robot or manipulator.

[0108] The code PR is preferably assigned using binary digital coding using a device, preferably a dip switch, installed in a communication module associated with the tool 6, in particular located in the tool adapter 2.

[0109] Preferably, the chip 109 has write access to a memory area 1101 separate from the memory area 1100 in which the security code Saut (the binary identification code PR, which is the tool's progressive number assigned by the user) is written.

[0110] The code PR may be written into the memory 1101 of the chip 109 by an external writing device 170 (shown in FIG. 2), which may be designed for example on a mobile phone or ad-hoc, with an application already available on the web, using known communication technologies such as NFC technology.

[0111] Preferably, the writing of this identification code PR of the tool in the chip 109 is password protected, just as the reading can be protected with the same or a different password.

[0112] Preferably, a binary identification code PR, which may be part of the safety signal S, is read by a reading device 104 when the tool 2 is connected and transferred, for example by a serial protocol (e.g. IO-Link) or a functional safety communication protocol (e.g. IO-Link Safety) to a processing unit 107 which can communicate with the control unit 150 of the robot or manipulator for appropriate checks.

[0113] Preferably, the safety signal S also includes a binary identification code PR.

[0114] The code PR is sent to the robot arm 5, specifically to the robot adapter 1, and thus to the control unit 150 of the robot or manipulator, which compares the code PR for a match with the tool number assigned in the robot or manipulator program.

[0115] The module 102, specifically the chip 109, has at least one digital port 1041, 1042 electrically connected to at least one electrical switch 113 of the magnetic sensor 112, and the at least one digital port 1041, 1042 is configured to change its state from a HIGH or LOW state to a LOW or HIGH state when the magnetic sensor is activated by the magnetic actuator 160 associated with the parking station 30.

[0116] The change in state of the at least one digital port 1041, 1042 is recorded in the memory 110 of the second module 102 and contributes to the formation of a safety signal S which the second module sends to the first module 101. The safety signal S thus includes the safety code Saut, the new state of the at least one digital port 1041, 1042 and preferably the code UID, the code PR and other codes stored in the memory 110.

[0117] The chip 109 preferably comprises two digital ports 1041, 1042 with individually configurable HIGH or LOW initial states, preferably the digital ports 1041, 1042 being individually configurable as digital input or output ports. The HIGH or LOW logic states of these ports are stored in a dedicated memory register 110 of the chip 109. The generation of a signal S depends on the state of at least one of the two ports 1041, 1042, preferably the state of at least one digital port configured as a digital input port, which signal is then sent to the first module 101 provided for enabling the operation of decoupling the tool 6 from the robot arm 5.

[0118] For example, the signal S of the module 102 is generated when at least one digital input port 1041, 1042 assumes a LOW state from an initial HIGH state due to activation of a magnetic sensor by the magnetic actuator 160 associated with the parking station 30. The LOW state of the at least one digital port 1041, 1042 is recorded in the memory 110 of the chip 109 and contributes to the formation of the safety signal S together with the at least one safety code Saut.

[0119] Further for example, the signal S of the module 102 is generated when at least one of the digital input ports 1041, 1042 assumes a HIGH state from an initial state of LOW due to activation of a magnetic sensor by the magnetic actuator 160 associated with the parking station 30. The HIGH state of the at least one of the digital ports 1041, 1042 is recorded in the memory 110 of the chip 109 and contributes to the formation of the safety signal S together with at least the safety code Saut.

[0120] Further, for example, the signal S of the module 102 is generated when both digital ports 1041, 1042 are configurable as input digital ports and when the activation of the magnetic sensor by the magnetic actuator 160 associated with the parking station 30 causes both digital ports 1041, 1042 to change state, i.e. from an initial state of both LOW to a state of HIGH, or from an initial state of both HIGH to a state of LOW, or from an initial state of one LOW and the other HIGH to a state of one HIGH and the other LOW. The states of both digital ports 1041, 1042 HIGH, both LOW, or one LOW and the other HIGH are recorded in the memory 110 of the chip 109 and contribute to forming the safety signal S together with at least the safety code Saut.

[0121] Preferably, the first module 101 transmits energy wirelessly to the second module 102, the same module 102 being provided with the possibility of harvesting the energy transmitted by the first module 101. The electrical energy harvested by the module 102 is partly supplied to the chip 109 and partly used to generate an electrical voltage Vout at an output supply port.

[0122] Preferably, both digital ports 1041, 1042 are configured as input digital ports connected to resistive loads and with respective high and low initial states (HIGH and LOW default states). Preferably, two LEDs, LED1, LED2, are interposed between the resistive loads and the digital ports 1041, 1042.

[0123] The chip 109 is connected via coupling means 114, for example an electrical cable with a four-pole male-female connector, to a magnetic sensor 112 with two switches 113 (one normally open and one normally closed, or two normally open, or two normally closed switches). Preferably, an output voltage Vout is provided from the chip 109 in parallel with both switches 113 of the magnetic sensor 112 via its output pin.

[0124] The two digital ports 1041 and 1042 are electrically connected to the electrical switch 113 of the magnetic sensor 112 .

[0125] Preferably, the magnetic sensor 112 allows a change in state of both ports 1041, 1042 once actuated by the magnetic actuator 160. Specifically, when the tool 6, and specifically the tool adapter 2, is not at the parking station 30 and, as a result, the magnetic sensor 112 is not actuated, if the sensor 112 has a normally open switch 113 and a normally closed switch 113, the state of the port 1041 of the chip 109 connected to the normally open switch 113 remains HIGH and the state of the other input port 1042 connected to the normally closed switch 113 remains LOW.

[0126] When a tool 6, specifically a tool adapter 2, is placed in the parking station 30 and the magnetic sensor 112 is activated, the state of the two ports 1041, 1042 of the chip 109 changes, with the state of the chip's port 1041 connected to the normally open switch 113 becoming LOW and the state of the other port 1042 connected to the normally closed switch 113 becoming HIGH.

[0127] The change in the state of the two input ports 1041, 1042, port 1041 in a LOW logical state and port 1042 in a HIGH logical state, makes it possible to generate a signal S that is sent to the first module 101 enabling the operation of disconnecting the tool 6 from the robot arm 5. The LOW state of the digital port 1041 and the HIGH state of the digital port 1042 are recorded in the memory 110 of the chip 109 and contribute to the formation of a safety signal S together with at least the safety code Saut.

[0128] According to the second variant of the embodiment of the present invention, the only difference with respect to the previously described safety control device 100 is that, in comparison with the first embodiment of the present invention and its variants, the second module 102 no longer comprises a magnetic sensor 112 and the magnetic actuator 160 is no longer present at the station 30.

[0129] According to a second embodiment of the invention, better illustrated in the figures 3a to 3d, the means 103 alternative to the magnetic actuator 160 comprises an electric circuit 1030 associated with the parking station 30. The module 102, and in particular the chip 109, comprises at least one digital port 1021, 1022 electrically connectable to the electric circuit 1030 associated with the parking station. However, also in this second embodiment, as in the first embodiment of the invention, the module 102, once supplied by the first module 101, is already capable of transmitting, and the memory 110 contains the security code Saut, i.e. a numeric or alphanumeric security string, and records the state changes of the at least one digital input port 1021, 1022.

[0130] At least one digital port 1021, 1022 is configured to change its state when connected to an electrical circuit 1030. In this way, the change of state is recorded in the memory 110 and the same change of state contributes to the formation of a signal S transmitted by the antenna 111.

[0131] Preferably, the second module comprises two digital ports 1021, 1022 with individually configurable HIGH or LOW states, preferably the digital ports 1021, 1022 are individually configurable as digital input or output ports. The HIGH or LOW state of at least the input digital port may be recorded in the memory 110, in particular in a dedicated memory register 110, and may be read by the reading device 104. The generation of a signal S depends on the state of at least one of the two ports 1021, 1022, i.e. the digital port configured as a digital input port, which signal is sent to the first module 101 provided to enable the operation of decoupling the tool 6 from the robot arm 5.

[0132] An electrical circuit 1030 associated with the parking station 30 is electrically connectable to the digital ports 1021 , 1022 via electrical contacts 1031 .

[0133] In the first configuration, shown in FIG. 3a, related to this second embodiment of the invention, the electrical circuit 1030 comprises two electrical wires, or any type of electrical component with the same function as two electrical wires, connected to GND ground and individually connectable to the two ports 1021, 1022 via electrical contacts 1031. The ports 1021, 1022 are typically configured as digital input ports with a HIGH state, such as an initial or default state. When the tool 6, preferably the tool adapter 2, is placed in the parking station 30, the two ports 1021, 1022 are connected to GND ground via the circuit 1030 and their state is LOW, and said LOW state of the digital ports 1021, 1022 contributes to the formation of a signal S, which is recorded in the memory 110 and transmitted to the first module 101.

[0134] Referring again to the second embodiment of the invention, in a second configuration shown in FIG. 3b, the electrical circuit 1030 comprises two electrical wires, or electrical components similar to electrical wires, connected together by a resistor R and individually connectable to the two ports 1021, 1022 via electrical contacts 1031. The digital ports 1021, 1022 are configured, one as an input digital port and one as an output digital port, and are configured in a HIGH state as an initial or default state. When the tool 6, preferably the tool adapter 2, is placed in the parking station 30, the two ports 1021, 1022 are connected to the resistor R via the circuit 1030, the state of the digital input port 1022 is LOW, and said LOW state of the digital port 1022 is recorded in the memory 110 and contributes to the generation of the signal S that is sent to the first module 101. Preferably, the port 1021 is configured as an output digital port (default state is HIGH) and the port 1022 is configured as an input digital port (default state is HIGH). When the tool adapter is placed in the parking station, the state of port 1022 goes LOW.

[0135] According to a variant of the second embodiment of the invention, a first module 101 wirelessly transmits energy to a second module 102, the same module 102 being provided with the possibility to collect the energy transmitted by the first module 101 (energy harvesting).

[0136] The electrical energy collected by the module 102 is partly employed to supply the chip 109 and partly used to generate an electrical voltage Vout at an output supply port, which can power an electrical circuit 1030 associated with the parking station 30 when the module 102 is connected. For example, the two digital ports 1021, 1022, preferably configured as input digital ports with an initial LOW state (default state is LOW), are directly connected to the voltage Vout via the circuit 1030 when the module 102 is connected to the circuit 1030 via the coupling of the electrical contacts 1031, as shown in FIG. 3c. When a tool 6, preferably a tool adapter 2, is placed in the parking station 30, the state of the two ports 1021, 1022 becomes HIGH, and said HIGH state of the digital ports 1021, 1022 is recorded in the memory 110 and contributes to the generation of a signal S that can be transmitted to the first module 101.

[0137] According to a further variant of the second embodiment of the invention, as shown in Fig. 3d, the second module 102 comprises, in addition to the chip 109, a very low consumption microprocessor 130, which is supplied by the voltage Vout present at the output supply port of the chip 109. The microprocessor 130 exchanges data with the chip 109 via a two-wire serial communication 131. The microprocessor 130 is permanently connectable to the circuit 1030 via electrical contacts 1031. The microprocessor 130 comprises a universal input / output port, generates a digital output signal and is able to read the state of a digital input port 133, which is connectable via the electrical contacts 1031 with the circuit contacts 1030 of the parking station 30, for example the circuit 1030 comprises electrical contacts connected in parallel and the microprocessor comprises a number of input ports 133, which are connectable via the contacts 1031 with corresponding electrical contacts of the circuit 1030. When a tool 6, preferably a tool adapter 2, is placed in the parking station 30, the connection between the contact 1031 and the circuit contact 1030 allows changing the state of the input port 133, which is communicated to the chip 109 by the two-wire serial communication 131. In this way, it is possible to create a signal S that is sent to the first module 101 in order to enable an operation to decouple the tool 6 from the robot arm 5 or an operation to couple the tool 6 to the robot arm 5.

[0138] The invention thus conceived is susceptible to a number of modifications and variations, all of which are within the scope of the inventive concept.

[0139] Preferably, the first module 101 is always active and does not need to transmit a signal Ssg for the start-up of the safety controller 100 .

[0140] Preferably, the control signal Ssg may be composed of two control signals.

[0141] Preferably, the first module 101 comprises two reading devices 104, e.g. RFID readers, each equipped with a specially designed antenna 105, both connected to the same control circuit 106, and preferably both reading devices 104 are connected to two microprocessors of the control circuit 106 in order to comply with the above mentioned safety standards.

[0142] Preferably, the chip 109 may be of the NFC type.

[0143] Preferably, due to the above-mentioned safety criteria requiring redundancy of the inhibiting means, the driver 500 comprises at least two independent electronic or electromechanical devices, each of which receives an authorization signal Aut from the processing unit 107 and generates one or more signals Ssgaut for the pneumatically actuated valve V1.

[0144] For example, in a variation of the above embodiment, the driver 500 comprises two independent electronic or electromechanical devices, each controlled by an authorization signal Aut derived from one of the two microprocessors.

[0145] For example, in another variation of the above embodiment, the control signal Ssg obtained from the control unit 150 of the robot arm or manipulator is sent to the valve actuation driver 500 rather than to the processing unit 107. The same driver also receives an authorization signal Aut from the processing unit 107, and the driver 500 itself controls the pneumatic valve V1 only if the control signal Ssg and the authorization signal Aut are received by the driver 500 simultaneously.

[0146] For example, in the above embodiment providing for the use of two electrical switches, when one switch is closed by an authorization signal Aut derived from one microprocessor, the switch enables the passage of a control signal Ssg to one of the two pneumatic valves by actuating the same valve to isolate the tool changer.

[0147] Moreover, all the details may be replaced by other technically equivalent elements.

[0148] In fact, the required shape and size as well as the materials used may be of any desired type without departing from the scope of protection of the following claims.

Claims

1. The robot arm (5) and the tool (6) are configured to be safely disconnected or connected to each other; a first module (101) associated with said robotic arm; a second module (102) associated with said tool; means (103) associated with the tool parking station (30) for inhibiting or allowing the generation of at least one safety signal (S, Saut, UID, PR) in said second module; Equipped with A safety control device (100) for a tool changing device of a robot arm, wherein the second module is configured to wirelessly transmit the at least one safety signal to the first module, and the first module is configured to allow decoupling or coupling between the robot arm and a tool in response to receiving the at least one safety signal.

2. 2. The device of claim 1, wherein at least the second module comprises a data storage means (110) and at least one digital port (1021, 1022; 1041, 1042; 133) that assumes an initial state, and wherein means (103) associated with the tool parking station (30) changes the initial state of the at least one digital port to a new state different from the initial state, the new state of the at least one digital port being stored in the storage means, and the at least one safety signal includes the new state of the at least one digital port.

3. 2. Apparatus according to claim 1, wherein said at least one safety signal comprises a safety code (Saut) in the form of a numeric or alphanumeric string stored in said storage means.

4. 4. The device according to claim 3, wherein the storage means (1101) of the second module is configured to store at least one code (PR) having a progressive number assigned to the tool, and wherein the at least one safety signal (S) wirelessly transmittable from the second module to the first module includes the at least one code having a progressive number assigned to the tool.

5. 4. The device according to claim 3, wherein said at least one code (PR) having a progressive number assigned to said tool is entered into said storage means by a user via an external communication module (170).

6. 2. The apparatus of claim 1, further comprising a control circuit (106, 150) associated with the first module, the control circuit (106) comprising a memory (1070) in which the at least one safety signal is stored, the control circuit (106) configured to perform an operation to verify a match between the at least one safety signal (S) emitted from the second module and received from the first module and the at least one safety signal present in the memory of the control circuit (106, 150), and after performing the verification operation, to allow disconnection or connection between the robot arm and the tool if the verification operation is affirmative.

7. 2. The device of claim 1, wherein the means (103) associated with the parking station comprises a magnetic actuator (160), and the second module comprises a magnetic sensor (112) operable by the magnetic actuator.

8. 2. The device of claim 1, wherein the means associated with the parking station comprises an electrical circuit (1030), and the at least one digital port of the second module is electrically connectable (1031) to the electrical circuit associated with the parking station.

9. The apparatus of claim 8 , wherein the second module is configured to power (Vout) the electrical circuitry (1030) associated with the parking station when connected to the parking station.

10. 8. The apparatus of claim 7, wherein the magnetic sensor comprises at least one electrical switch (113) commanded by the magnetic actuator, the at least one digital port (1041, 1042) of the second module is electrically connected to the at least one electrical switch (113) of the magnetic sensor, and the at least one digital port is configured to change state when the magnetic sensor is activated by the magnetic actuator associated with the parking station.

11. The apparatus of claim 10 , wherein the second module is configured to power the electrical contacts of the magnetic sensor.

12. 2. The apparatus of claim 1, wherein the means associated with the parking station comprises an electrical circuit, the second module comprises at least one microprocessor (130) electrically connectable to the electrical circuit associated with the parking station, and the second module is configured to power the microprocessor and the electrical circuit associated with the parking station when connected to the parking station.

13. 2. The apparatus of claim 1, wherein the first module comprises an RFID reader (104) and the second module comprises at least one RFID chip (109).

14. A tool changing device for a robot arm comprising a safety control device (100) according to claim 1.

15. 15. The device of claim 14, comprising a robot adapter (1) connected to the robot arm (5) and a tool adapter (2) connected to the tool (6), wherein the first module (101) is disposed in the robot adapter and the second module (102) is disposed in the tool adapter.

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