Safety circuit for a passenger transport system, passenger transport system, and method for operating a safety circuit for a passenger transport system

Abstract

A safety circuit (20) for a passenger transport system (1) is described. The passenger transport system (1) comprises at least one control unit (16) for controlling at least one function of the passenger transport system (1). The safety circuit (20) comprises: two or more safety switches in series (15) being configured for stopping at least one function of the passenger transport system (1) upon activation of at least one of the safety switches (15) in case of a safety risk; and two or, respectively, more microcontrollers (22), with each of the microcontrollers (22) being coupled to the control unit (16) and to a corresponding one of the safety switches (15) and comprising a unique identification, wherein the safety switches (15) and the corresponding microcontrollers (22) are coupled with each other such that when one of the safety switches (15) is activated the corresponding one of the microcontrollers (22) is activated, and wherein the microcontrollers (22) are configured for sending the corresponding identification to the control unit (16) upon their activation.

Description

[0001] Safety Circuit for a Passenger Transport System, Passenger Transport System, and Method for Operating a Safety Circuit for a Passenger Transport System

[0002] The technology described herein generally relates to a safety circuit for a passenger transport system, to a passenger transport system, and to a method for operating a safety circuit for a passenger transport system. More particularly, the technology relates to a safety circuit for a passenger transport system, to the passenger transport system, and to a method for operating the safety circuit for the passenger transport system.

[0003] A passenger transport system may be an elevator, an escalator or a moving pavement. An elevator serves for transporting passengers with a car of the elevator throughout a hoistway within a building. Typically, a multiplicity of passengers and / or one or more goods may be accommodated within the car and may then be transported from a starting floor to a destination floor in the building. During such travel, further passengers may enter or exit the cabin during intermediate stops at other floors. An escalator also serves for transporting passengers from a starting floor to a destination floor in a building, wherein the passengers are transported by moving stair or step elements of the escalator. A moving pavement may be seen as an escalator which extends in horizontal direction and which serves to transport the passengers from one location to another location within the same floor of the corresponding building.

[0004] Each modem passenger transport system comprises one or more safety switches which may be activated automatically or manually in case of a safety risk. In case of an elevator as the passenger transport system, the safety switches may be arranged next to the hoistway doors of the corresponding elevator hoistway, within the car of the elevator, on top of the car, or in a pit of the elevator. In case of an escalator or moving pavement, the safety switches may be arranged at or close to a first end of the escalator or, respectively moving pavement, to a second end of the escalator or, respectively moving pavement opposite to the first end, and / or at one or more positions between the first and second ends. When one of the safety switches is activated, a signal may be sent to a control unit of the corresponding passenger transport system and at least one safety measure may be activated. However, in case of two or more safety switches that may be installed in series, the control unit is not able to identify which one of the safety switches was activated. Therefore, it may be a cumbersome task to find out which safety switch was activated and thereby which safety risk occurred.

[0005] Accordingly, there may be a need for an improved safety circuit for a passenger transport system, which may contribute to enable a control unit of the passenger transport system in case of a safety risk to find out where the safety risk occurred. Further, there may be a need for a passenger transport system comprising the improved safety circuit. Furthermore, there may be a need for a method for operating the safety circuit for the passenger transport system such that the safety circuit may achieve the results and advantages described above.

[0006] Such need may be met with the subject-matter of the independent claims. Advantageous embodiments are defined in the dependent claims as well as in the following specification and the associated figures.

[0007] According to a first aspect of the technology described herein, a safety circuit for a passenger transport system is proposed. The passenger transport system comprises at least one control unit for controlling at least one function of the passenger transport system. The safety circuit comprises: two or more safety switches being configured for stopping at least one function of the passenger transport system upon activation of at least one of the safety switches in case of a safety risk; and two or, respectively, more microcontrollers, with each of the microcontrollers being coupled to the control unit and to a corresponding one of the safety switches and comprising a unique identification, wherein the safety switches and the corresponding microcontrollers are coupled with each other such that when one of the safety switches is activated the corresponding one of the microcontrollers is activated, and wherein the microcontrollers are configured for sending the corresponding identification to the control unit upon their activation.

[0008] According to a second aspect of the technology described herein, the passenger transport system is proposed. The passenger transport system comprises: the control unit for controlling the at least one function of the passenger transport system; and the safety circuit as described above and in the following, wherein the control unit is configured for carrying out at least one safety measure upon receiving the identification of one of the microcontrollers . According to a third aspect of the technology described herein, a method for operating the safety circuit for the passenger transport system is proposed. The passenger transport system comprises the at least one control unit for controlling the at least one function of the passenger transport system. The method comprises: activating one of the microcontrollers associated with the corresponding safety switch of the safety circuit upon the safety switch being activated in case of the safety risk; and sending the unique identification of the microcontroller to the control unit upon activation of the microcontroller.

[0009] It shall be noted that possible features and advantages of embodiments of the technology described herein are described herein partly with respect to one of the above aspects and partly with respect to another one of the above aspects. One skilled in the art will recognize that the features may be suitably transferred from one aspect to another aspect and / or from one embodiment to another embodiment, and features may be modified, adapted, combined and / or replaced, etc. in order to come to further embodiments of the technology described herein.

[0010] The microcontrollers being assigned to the corresponding safety switches and sending their identification to the control unit of the passenger transport system enable the control unit to identify which safety switch was activated. This may contribute to find a reason for the safety risk and thereby to eventually remedy the safety risk in a quick and / or easy way, and / or to find a proper safety measure in order to avoid any injury or damage because of the safety risk.

[0011] The passenger transport system may comprise an elevator, an escalator, or a moving pavement. The safety switches may be arranged at different positions at the passenger transport system or close to the passenger transport system. For example, in case of an escalator or moving pavement as the passenger transport system, the safety switches may be arranged at or close to a first end of the escalator or, respectively moving pavement, to a second end of the escalator or, respectively moving pavement opposite to the first end, and / or at one or more positions between the first and second ends. Alternatively, in case of an elevator as the passenger transport system, the safety switches may be arranged next to the hoistway doors of the corresponding elevator hoistway, within a car of the elevator, on top of the car, or in a pit of the elevator hoistway.

[0012] The functions of the passenger transport system being controlled by the control unit may for example be any function regarding a movement of that part of the passenger transport system which transports the passenger and / or which grants or denies an access to that part of the passenger transport system which transports the passenger. For example, in case of an elevator, the function may be a movement of the corresponding car, e.g. in vertical direction. This function may be controlled by the control unit via a motor for lifting the car. Alternatively, in case of the elevator, the function may be a movement of one or more doors of the car or the hoistway in which the car is arranged. In particular, in these cases, the car may be stopped and / or, respectively, an opening or closing of the door of the car and / or of the hoistway may be stopped, when the corresponding safety switch is activated. Alternatively, in case of an escalator or moving pavement, the function may be a movement of the moving parts of the moving pavement on which the passengers stand while being transported. In this case, the movement of the escalator or moving pavement may be stopped, when the corresponding safety switch is activated.

[0013] The function may be stopped by the safety switch directly, or by the microcontroller, or via the microcontroller by the control unit upon receiving the ID of the microcontroller. The microcontrollers being coupled to the control unit may be communicatively coupled to the control unit such that one or more signals may be sent from the microcontrollers to the control unit, e.g. by one or more wires or wireless. The microcontrollers being coupled to the corresponding safety switch may be directly connected to the corresponding safety switches by one or more electrically conductive vias. For example, each of the microcontrollers and the corresponding safety switch may be arranged close to each other, e.g. in the same casing or on the same Printed Circuit Board (PCB). The unique identification may be a code or a number.

[0014] According to an embodiment, the safety switches are coupled to the corresponding microcontrollers by corresponding Single-Pole-Double-Throw(SPDT)-contacts. This may contribute to securely and easily activate the microcontrollers upon activation of the corresponding safety switch. In general, an SPDT-contact has one switch which is controlled by a single physical actuator and a contact that can be connected to either of two other contacts. In other words, the SPDT-contact enables connecting either of two terminals to one common terminal.

[0015] According to an embodiment, each of the microcontrollers is coupled to an energy source such that the microcontrollers are activated by being supplied with energy when the corresponding safety switch is activated. This may contribute to a low energy consumption, because the microcontroller does need any energy as long as the safety switch is not activated. For example, in case of the safety switches being coupled to the corresponding microcontrollers by corresponding SPDT-contacts, the safety switches, the corresponding microcontrollers, and the energy source(es) may be coupled to each other by the SPDT-contact such that the microcontrollers are coupled to the energy source by the SPDT-contact when the corresponding safety switch is activated. The energy source may be the same energy source from which energy is supplied to the safety switch and / or the control unit. Alternatively, the energy source may be a battery directly connected to the microcontroller.

[0016] According to an embodiment, the safety switches are configured for being operated by a person being aware of the safety risk, i.e. manually, or the safety switches are configured for being operated automatically when the safety risk is recognized automatically. For example, in case of the manual activation, the safety switch may comprise a button, e.g. a big red one, which may be easily activated by the person. Alternatively, the safety risk may be recognized automatically by one or more sensors of the passenger transport system, in particular of the safety circuit.

[0017] According to an embodiment, the safety circuit comprises the control unit of the passenger transport system, wherein the control unit is configured for stopping the at least one function of the passenger transport system controlled by the control unit upon receiving the identification of one of the microcontrollers. So, the control unit may be seen as a part of the safety circuit which may carry out one or more safety measures in case of the safety risk. This may contribute to avoid any damage or injury because of the safety risk.

[0018] According to an embodiment, the safety measure carried out by the control unit upon receiving the identification of one of the microcontrollers is stopping the at least one function of the passenger transport system controlled by the control unit. For example, if the function of the control unit is moving the car of the elevator or the stairs of the escalator, or if the function is moving a door of the elevator, the safety measure may be stopping the corresponding movement. This may contribute to avoid any damage or injury because of the safety risk.

[0019] According to an embodiment, the method comprises stopping at least one function of the passenger transport system upon activation of the safety switch. This may contribute to avoid any damage or injury because of the safety risk. In particular, in this embodiment, the function may be stopped without and / or independent from the control unit, e.g. by the safety switch only, but the control unit is informed by the microcontroller, which safety switch was activated and / or stopped the function. The function may be stopped by the safety switch directly, or by the microcontroller, or via the microcontroller by the control unit upon receiving the ID of the microcontroller.

[0020] In the following, advantageous embodiments of the technology described herein will be described with reference to the enclosed drawings. However, neither the drawings nor the description shall be interpreted as limiting the technology described herein.

[0021] Fig. 1 shows a cutaway side view of a passenger transport system, according to an embodiment of the technology described herein.

[0022] Fig. 2 shows a block diagram of a safety circuit of the passenger transport system in a first state, according to an embodiment of the technology described herein.

[0023] Fig. 3 shows a block diagram of the safety circuit of figure 2 in a second state.

[0024] Fig. 4 shows a flow-chart of a method for operating a safety circuit of a passenger transport system, according to an embodiment of the technology described herein.

[0025] The figures are only schematic and not to scale. Same reference signs refer to same or similar features. Fig. 1 shows a cutaway side view of a passenger transport system 1, according to an embodiment of the technology described herein. The passenger transport system 1 may be configured for transporting one or more passengers and / or goods from one floor 10 to another floor 10 of a building or from one position to another position within the same floor of the building. In this embodiment, the passenger transport system 1 is an elevator. However, in other embodiments of the present invention, the passenger transport system 1 may be an escalator or a moving pavement.

[0026] The elevator is arranged in a building having an elevator hoistway 3. The elevator comprises an elevator car 5. The elevator car 5 is displaceably arranged, e.g. vertically, in the elevator hoistway 3. The elevator car 5 is mechanically coupled to a counterweight 2 of the elevator via at least one suspension element 4, for example a rope. The suspension element 4 may be guided between the elevator car 5 and the counterweight 2 via one or more deflection rollers 12. The suspension element 4 and thus the elevator car 5 and the counterweight 2 are movable by means of a motor (not shown) of the elevator, whereby the displacement of the elevator car 5 may be realized. The motor may be controlled by means of a control unit 16. The control unit 16 may be arranged on the elevator car 5. However, the control unit 16 may also be arranged at another location of the elevator, for example in the area of a ceiling of the elevator hoistway 3.

[0027] The elevator car 5 may be configured for accommodating the person(s) and / or load(s) to be transported. The elevator car 5 has a car opening 6 through which the persons can enter or leave the elevator car 5, or through which the loads can be brought into or taken out of the elevator car 5. The elevator car 5 has a car door 7 for exposing or closing the car door opening 6. The elevator may comprise a car door drive 8 that is mechanically coupled to the car door 7 in such a way that the car door 7 can be moved, in particular opened or closed, by means of the car door drive 8. Corresponding mechanical couplings are known from the prior art. The elevator may comprise a car door control 14 which is communicatively coupled to the car door drive 8 in such a way that the car door drive 8 may be controlled by means of the car door control 14. In particular, the car door control 14 may be communicatively coupled to the car door drive 8 in such a way that the car door control 14 can transmit control signals to the car door drive 8, for example wirelessly or by cable. The elevator hoistway 3 may comprise a hoistway opening 9 at each floor 10 to provide access to respective floors 10 of the building starting from the elevator car 5. A hoistway door 11 may be arranged at each of these hoistway openings 9. If the elevator car 5 is located on one of the floors 10, the corresponding hoistway opening 9 may be located opposite the car door 7. With car door 7 open and hoistway door 11 open, the elevator car 5 may then be entered or exited from the corresponding floor 10.

[0028] The elevator may comprise a hoistway door drive 13 and a hoistway door control 19. The hoistway door drive 13 may be mechanically coupled to the hoistway door 11 in such a way that the hoistway door 11 may be moved, in particular opened or closed, by means of the hoistway door drive 11. Corresponding mechanical couplings are known from the prior art. The hoistway door control 19 may be communicatively coupled to the hoistway door drive 13 in such a way that the hoistway door drive 13 may be controlled by means of the hoistway door control 19. In particular, the hoistway door control 19 may be communicatively coupled to the hoistway door drive 13 in such a way that the hoistway door control 19 can transmit control signals to the hoistway door drive 13, for example wirelessly or by cable.

[0029] The car door control 14 and the hoistway door control 19 may be communicatively coupled to the control unit 16 of the elevator. In particular, the car door control 14 and the hoistway door control 19 may be coupled to the control unit 16 such that one or more control signals and / or sensor signals may be exchanged between the car door control 14 and the control unit 16 and / or between the hoistway door control 19 and the control unit 16. For example, the control unit 16 may be configured for initiating and / or for stopping a movement of the car door 7 and / or of the hoistway door 11 via the corresponding door control 14, 19.

[0030] Functions of the passenger transport system 1 being controlled by the control unit 16 may for example be any function regarding a movement of that part of the passenger transport system 1 which transports the passenger(s) and / or which grants or denies an access to that part of the passenger transport system 1 which transports the passenger(s). For example, in case of the elevator, the function may be a movement of the car 5, e.g. in vertical direction. This function may be controlled by the control unit 16 via the motor for lifting the car 5. Alternatively, in case of the elevator, the function may be a movement of one or more of the doors 7, 11 of car 5 or the hoistway 3. Alternatively, in case of an escalator or moving pavement, the function may be a movement of the moving parts of the moving pavement on which the passengers stand while being transported.

[0031] The passenger transport system 1 comprises two or more safety switches 15 being configured for stopping at least one function of the passenger transport system 1 upon activation of at least one of the safety switches 15 in case of a safety risk. The safety switches 15 may be arranged at different positions at the passenger transport system 1 or close to the passenger transport system 1. For example, in case of the elevator as the passenger transport system 1, the safety switches 15 may be arranged next to the hoistway doors 11 of the elevator hoistway 3, within the car 5 of the elevator, on top of the car 5, or in a pit of the elevator hoistway 3. Alternatively, in case of the escalator or moving pavement as the passenger transport system 1, the safety switches 15 may be arranged at or close to a first end of the escalator or, respectively moving pavement, to a second end of the escalator or, respectively moving pavement opposite to the first end, and / or at one or more positions between the first and second ends (not shown).

[0032] The safety switches 15 may be configured for being operated by a person being aware of the safety risk, i.e. manually. For example, each of the safety switches 15 may comprise a button, e.g. a big red one, which may be easily activated by the person. Alternatively, one or more of the safety switches 15 may be configured for being operated automatically when the safety risk is recognized automatically, e.g. by one or more sensors of the passenger transport system 1.

[0033] The function of the passenger transport system 1 to be stopped upon the activation of at least one of the safety switches 15 in case of the safety risk may be stopping the movement of the car 5 and / or stopping the opening or closing of the door 7, 11 of the car 5 and / or of the hoistway 3, when the corresponding safety switch 15 is activated, in case of the passenger transport system 1 being the elevator. In case of the escalator or moving pavement, the function of the passenger transport system 1 to be stopped upon the activation of at least one of the safety switches 15 in case of the safety risk may be stopping the movement of the stairs of the escalator or segments of the moving pavement, when the corresponding safety switch 15 is activated. Fig. 2 shows a block diagram of a safety circuit 20 of the passenger transport system 1 in a first state, according to an embodiment of the technology described herein. The safety circuit 20 comprises two or more of the safety switches 15 being configured for stopping at least one function of the passenger transport system 1 upon activation of at least one of the safety switches 15 in case of a safety risk. The safety circuit 20 further comprises two or more microcontrollers 22, one for each safety switch 15. The passenger transport system 1 may comprise one safety circuit 20 comprising two or more safety switches 15 and corresponding microcontrollers 22, or the passenger transport system 1 may comprise two or more safety circuits 20, each comprising one safety switch 15 and one corresponding microcontroller 22.

[0034] The safety switches 15 may be coupled to the corresponding microcontrollers 22 by corresponding Single-Pole-Double-Throw(SPDT)-contacts. Each SPDT-contact may be one switch which is controlled by a single physical actuator, i.e. the corresponding safety switch 15, and a contact which is coupled to the control unit 16 and that can be connected to either of two other contacts, wherein one of these contacts may be coupled to the corresponding microcontroller 22 and wherein the other one of these contacts may be coupled to the control unit 16.

[0035] So, in the first state shown in figure 2, the safety switch 15 is not activated and the microcontroller 16 is not coupled to the control unit 16 and no energy is supplied to the microcontroller 16.

[0036] Fig. 3 shows a block diagram of the safety circuit 20 of figure 2 in a second state. In the second state, the safety switch 15 is activated, and the corresponding microcontroller 22 is coupled to the control unit 16 and supplied with energy. Each of the microcontrollers 22 comprises a unique identification. The unique identification may be a code or a number.

[0037] The safety switches 15 and the corresponding microcontrollers 22 are coupled with each other such that when one of the safety switches 15 is activated the corresponding one of the microcontrollers 22 is activated. The microcontrollers 22 being coupled to the corresponding safety switch 15 may be directly connected to the corresponding safety switch 15 by one or more electrically conductive vias. For example, each of the microcontrollers 22 and the corresponding safety switch 15 may be arranged close to each other, e.g. in the same casing or on the same Printed Circuit Board (PCB) (not shown).

[0038] The microcontrollers 22 may be communicatively coupled to the control unit 16 such that one or more signals may be sent from the microcontrollers 22 to the control unit 16, e.g. by one or more wires or wireless. The microcontrollers 22 are configured for sending the corresponding identification to the control unit 16 upon their activation.

[0039] The microcontrollers 22 may be coupled to an energy source such that the microcontrollers 22 are activate by being supplied with energy when the corresponding safety switch 15 is activated. The safety switch 15 may be supplied with energy from the control unit 16 via a diode 24 and a capacitor 26. The diode 24 may be coupled to the single pole of the SPDT-contact, to the capacitor 26 and to the microcontroller 22, whereas the capacitor 26 may be coupled to one of the two contacts of the SPDT-contact which is connected to the control unit 16. So, each of the microcontrollers 22 is coupled to the corresponding safety switch 15 and in the second state to the control unit 16. In particular, in case of the safety switches 15 being coupled to the corresponding microcontrollers 22 by corresponding SPDT-contacts, the safety switches 15, the corresponding microcontrollers 22 and the energy source(es) are coupled to each other by the SPDT-contact such that the microcontrollers 22 are coupled to the energy source by the SPDT-contact when the corresponding safety switch 15 is activated. The energy source may be the same energy source from which energy is supplied to the safety switch 15 and / or the control unit 16. Alternatively, the energy source may be a battery (not shown) directly connected to the microcontroller 22.

[0040] The function of the passenger transport system 1 to be stopped may be stopped by the safety switches 15 directly, or by the microcontroller 22, or via the microcontroller 22 by the control unit 16 upon receiving the ID of the microcontroller 22. For example, the safety measure carried out by the control unit 16 upon receiving the identification of one of the microcontrollers 22 may be stopping the at least one function of the passenger transport system 1 controlled by the control unit 16, as described above. For example, if the function of the control unit 16 is moving the car 5 of the elevator or the stairs of the escalator, or if the function is moving one of the doors 7, 11 of the elevator, the safety measure may be stopping the corresponding movement. Fig. 4 shows a flow-chart of a method for operating the safety circuit 22 of the passenger transport system 1, according to an embodiment of the technology described herein.

[0041] In a step S2, one of the microcontrollers 22 associated with one of the safety switches 15 of the safety circuit 22 may be activated upon the corresponding safety switch 15 being activated in case of the safety risk.

[0042] In a step S4, the unique identification of the microcontroller 22 may be sent to the control unit 16 upon the activation of the microcontroller 22.

[0043] In a step S6, the at least one function of the passenger transport system 1 may be stopped upon activation of the safety switch 15. The function may be stopped without and / or independent from the control unit 16, e.g. by the safety switch 15 only, but the control unit 16 is informed by the microcontroller 22, which safety switch 15 was activated and / or stopped the function. The function may be stopped by the safety switch 15 directly, or by the microcontroller 22, or via the microcontroller 22 by the control unit 16 upon receiving the ID of the microcontroller 22.

[0044] Finally, it should be noted that the term “comprising” does not exclude other elements or steps and the “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

Claims:

1. Safety circuit (20) for a passenger transport system (1), with the passenger transport system (1) comprising at least one control unit (16) for controlling at least one function of the passenger transport system (1), the safety circuit (20) comprising: two or more safety switches (15) being configured for stopping at least one function of the passenger transport system (1) upon activation of at least one of the safety switches (15) in case of a safety risk; and two or, respectively, more microcontrollers (22), with each of the microcontrollers (22) being coupled to the control unit (16) and to a corresponding one of the safety switches (15) and comprising a unique identification, wherein the safety switches (15) and the corresponding microcontrollers (22) are coupled with each other such that when one of the safety switches (15) is activated the corresponding one of the microcontrollers (22) is activated, wherein each of the microcontrollers (22) is coupled to an energy source (28) such that the microcontrollers (22) are activated by being supplied with energy when the corresponding safety switch (15) is activated, and the microcontrollers (22) are configured for sending the corresponding identification to the control unit (16) upon their activation.

2. Safety circuit (20) according to claim 1, wherein the safety switches (15) are coupled to the corresponding microcontrollers (22) by corresponding Single-Pole-Double-Throw contacts.

3. Safety circuit (20) according to any one of the preceding claims, wherein the safety switches (15) are configured for being operated by a person being aware of the safety risk, or the safety switches (15) are configured for being operated automatically when the safety risk is recognized automatically.

4. Safety circuit (20) according to any one of the preceding claims, comprising the control unit (16) of the passenger transport system (1), whereinthe control unit (16) is configured for stopping the at least one function of the passenger transport system (1) controlled by the control unit (16) upon receiving the identification of one of the microcontrollers (22).

5. Passenger transport system (1), comprising: a control unit (16) for controlling at least one function of the passenger transport system (1); and a safety circuit (20) according to any one of claims 1 to 4, wherein the control unit (16) is configured for carrying out at least one safety measure upon receiving the identification of one of the microcontrollers (22).

6. Passenger transport system (1) according to claim 5, wherein the safety measure carried out by the control unit (16) upon receiving the identification of one of the microcontrollers (22) is stopping the at least one function of the passenger transport system (1) controlled by the control unit (16).

7. Method for operating a safety circuit (20) for a passenger transport system (1), with the passenger transport system (1) comprising at least one control unit (16) for controlling at least one function of the passenger transport system (1), the method comprising: activating a microcontroller (22) associated with a safety switch (15) of the safety circuit (20) upon the safety switch (15) being activated in case of a safety risk; and sending a unique identification of the microcontroller (15) to the control unit (16) upon activation of the microcontroller (15).

8. Method according to claim 7, comprising: stopping at least one function of the passenger transport system (1) upon activation of the safety switch (15).

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