ELEVATOR SYSTEM WITH COMBINED LiDAR AND VISIBLE SENSOR GUIDE

Abstract

The invention relates to an elevator system with a combined LiDAR and visible light sensor guide, in particular to a sensor having a housing extending from a front portion to a rear portion wherein the front portion has a transparent cover glass; an infrared (IR) beam emitter within the housing that emits a first beam along a first path; a visible light beam emitter within the housing that emits a second light beam along a second path that is not consistent with the first path; and a beam guide within the housing that engages the first and second beams such that the first and second beams are coaxial or parallel and exit the front of the housing.

Description

Technical Field

[0001] The embodiments described herein relate to elevator systems, and more specifically, to elevator systems with combined LiDAR and visible light sensor guides. Background Technology

[0002] What is needed is continuous detection of when a mechanic might be moving elevator components (such as the elevator car or counterweight) along their path within the shaft. Using LiDAR sensors can aid in this detection. However, the timing of sensor installation can be a concern, one factor being sensor alignment. Summary of the Invention

[0003] A sensor includes: a housing extending from a front to a rear, wherein the front has a transparent cover glass; an infrared (IR) beam emitter within the housing that emits a first beam along a first path; a visible beam emitter within the housing that emits a second beam along a second path inconsistent with the first path; and a beam guide within the housing that engages the first and second beams such that the first and second beams are coaxial or parallel and exit from the front of the housing.

[0004] In addition to one or more aspects of the sensor, or as an alternative, the IR beam emitter is a near-infrared laser diode (NIR-LD) that emits a first beam along a first path, wherein the first path faces the front of the housing; the visible beam emitter is a visible laser diode (VLD) that emits a second beam along a second path; and the beam guide is a dichroic mirror disposed along the first path and at a first angle to the second path, such that the first and second beams are coaxial or parallel and exit the front of the housing.

[0005] In addition to one or more aspects of the sensor, or as an alternative, the beam guide is configured to allow the transmission of the first beam and the reflection of the second beam.

[0006] In addition to one or more aspects of the sensor, or as an alternative, the sensor includes: a beam emitting member on a first side of the housing, the beam emitting member including an IR beam emitter, a first lens, and a beam expander from the rear to the front of the housing; and a beam receiving member on a second side of the housing, the beam receiving member including a second lens, an optical filter, and a detector array from the front to the rear of the housing.

[0007] In addition to one or more aspects of the sensor, or as an alternative, the beam expander is a diffractive optical element (DOE) or a diffuser.

[0008] In addition to one or more aspects of the sensor, or as an alternative, the detector array includes photodiodes.

[0009] In addition to one or more aspects of the sensor, or as an alternative, the photodiode is an avalanche photodiode (APD) or a complementary metal-oxide-semiconductor (CMOS).

[0010] In addition to one or more aspects of the sensor, or as an alternative, the VLD is located on the first side of the housing, adjacent to the beam emitting member.

[0011] In addition to one or more aspects of the sensor, or as an alternative, the VLD is configured such that the second path is perpendicular to the first path before engaging the beam guide.

[0012] An elevator system includes: an elevator car having a car top and a guardrail mounted to the car top; and one or more sensors having one or more aspects disclosed above mounted on the guardrail.

[0013] In addition to one or more aspects of the elevator system, or as an alternative, the elevator system includes multiple sensors mounted to the guardrails and distributed around the top of the elevator car.

[0014] In addition to one or more aspects of the elevator system, or alternatively, the elevator system includes an elevator controller configured to: receive sensor data from one or more sensors; and, upon determining that the sensor data indicates that an object has been detected on the top of the elevator car, stop the elevator car or put the elevator car into maintenance mode.

[0015] In addition to one or more aspects of the elevator system, or as an alternative, the elevator controller is configured to communicate with one or more sensors via a wireless network.

[0016] Another embodiment of the elevator system includes: a shaft defining a pit; a pit ladder having steps; and one or more sensors having one or more aspects disclosed above, which are mounted in the pit and configured such that an emitted beam from another sensor extends adjacent to each step of the pit ladder.

[0017] In addition to one or more aspects of another embodiment of the elevator system, or as an alternative, the elevator system includes an elevator controller configured to: receive sensor data from one or more sensors; and, upon determining that the sensor data indicates that an object has been detected on the pit ladder, stop the elevator car of the system or put the elevator car into maintenance mode.

[0018] In addition to one or more aspects of the elevator system, or as an alternative, the elevator controller is configured to communicate with one or more sensors via a wireless network.

[0019] A method of controlling an elevator system includes: monitoring sensor data from one or more sensors located on the top of an elevator car via a controller, the sensor data indicating that an object has been detected on the top of the elevator car, wherein each sensor includes: a housing extending from a front to a rear, wherein the front has a transparent cover glass; an infrared (IR) beam emitter within the housing that emits a first beam along a first path; a visible beam emitter within the housing that emits a second beam along a second path inconsistent with the first path; and a beam guide within the housing that engages the first and second beams such that the first and second beams are coaxial or parallel and exit the front of the housing; and stopping the elevator car or putting the elevator car into a maintenance mode when it is determined that the sensor data indicates that an object has been detected on the top of the elevator car.

[0020] In addition to one or more aspects of the method, or as an alternative, the method includes: confirming the alignment of one or more sensors relative to the top of the elevator car by visually inspecting whether a second beam emitted from one or more sensors extends above and parallel to the top of the elevator car.

[0021] Another embodiment of the method for controlling an elevator system includes: monitoring sensor data from one or more sensors located in the pit of the shaft via a controller, the sensor data indicating that an object has been detected on a pit ladder located in the pit, wherein each sensor includes: a housing extending from a front to a rear, wherein the front has a transparent cover glass; an infrared (IR) beam emitter within the housing that emits a first beam along a first path; a visible beam emitter within the housing that emits a second beam along a second path inconsistent with the first path; and a beam guide within the housing that engages the first and second beams such that the first and second beams are coaxial or parallel and exit the front of the housing; and stopping the elevator car of the system or operating the elevator car in maintenance mode when it is determined that the sensor data indicates that an object has been detected on the pit ladder.

[0022] In addition to one or more aspects of another embodiment of the method, or as an alternative, the method includes confirming the alignment of one or more sensors relative to the pit ladder by visually inspecting whether a second beam emitted from one or more sensors is along the pit ladder and adjacent to the steps of the pit ladder. Attached Figure Description

[0023] This disclosure is illustrated by way of example and is not limited to the accompanying drawings, wherein like reference numerals denote like elements.

[0024] Figure 1 These are schematic diagrams of elevator systems that may employ various embodiments of the present disclosure;

[0025] Figure 2 A shows the relationship with Figure 1 Sensors used in elevator systems;

[0026] Figure 2 B shows additional aspects of the sensor;

[0027] Figure 3 A method for controlling an elevator system with sensors installed in the elevator car is shown;

[0028] Figure 3 A method for controlling an elevator system with sensors installed in the pit is shown; and

[0029] Figure 4 This is a flowchart showing the method of controlling the elevator system. Detailed Implementation

[0030] Figure 1 This is a perspective view of elevator system 101, which includes elevator car 103, counterweight 105, tensioning member 107, guide rails (or track system) 109, machine (or machine system) 111, position reference system 113, and electronic elevator controller (controller) 115. Elevator car 103 and counterweight 105 are connected to each other via tensioning member 107. Tensioning member 107 may include or be configured as, for example, ropes, cables, and / or coated steel strips. Counterweight 105 is configured to balance the load of elevator car 103 and to facilitate simultaneous and opposite movement of elevator car 103 relative to counterweight 105 within elevator shaft (or hoistway) 117 and along guide rails 109.

[0031] Tensioning component 107 engages machine 111, which is part of the top structure of elevator system 101. Machine 111 is configured to control movement between elevator car 103 and counterweight 105. Position reference system 113 may be mounted to a fixed portion at the top of elevator shaft 117, such as to a support or guide rail, and may be configured to provide a position signal relating to the position of elevator car 103 within elevator shaft 117. In other embodiments, position reference system 113 may be mounted directly to a moving component of machine 111, or may be located in other locations and / or configurations known in the art. Position reference system 113 may be any device or mechanism known in the art for monitoring the position of elevator car and / or counterweight. For example, but not limited to, position reference system 113 may be an encoder, sensor, or other system, and may include speed sensing, absolute position sensing, etc., as will be understood by those skilled in the art.

[0032] Controller 115 may be located in control room 121 of elevator shaft 117 as shown, and is configured to control the operation of elevator system 101, and specifically control the operation of elevator car 103. It should be understood that controller 115 is not necessarily in control room 121, but may be in the shaft or other location within the elevator system. For example, controller 115 may provide drive signals to machine 111 to control the acceleration, deceleration, leveling, stopping, etc., of elevator car 103. Controller 115 may also be configured to receive position signals from position reference system 113 or any other desired position reference device. As elevator car 103 moves up and down along guide rails 109 within elevator shaft 117, elevator car 103 may stop at one or more platforms 125 under the control of controller 115. Although shown in controller room 121, those skilled in the art will understand that controller 115 may be located and / or configured in other locations or places within elevator system 101. In one embodiment, the controller may be located remotely or in the cloud.

[0033] Machine 111 may include a motor or similar drive mechanism. According to embodiments of this disclosure, machine 111 is configured to include an electrically driven motor. The power supply for the motor can be any power source, including the power grid, which, in combination with other components, supplies power to the motor. Machine 111 may include traction pulleys that apply force to tensioning member 107 to move elevator car 103 within elevator shaft 117.

[0034] Although shown and described together with the rope system including tensioning member 107, elevator systems employing other methods and mechanisms for moving the elevator car within the elevator shaft can adopt embodiments of this disclosure. For example, embodiments can be used in cordless elevator systems that use a linear motor to apply motion to the elevator car. Embodiments can also be used in cordless elevator systems that use a hydraulic lift to apply motion to the elevator car. Embodiments can also be used in cordless elevator systems that use a self-propelled elevator car (e.g., an elevator car equipped with friction wheels, clamping wheels, or traction wheels). Figure 1 These are non-restrictive examples presented merely for illustrative and explanatory purposes.

[0035] Elevator car 103 may have a car top 103A, which has a safety railing 103B to ensure that the first mechanic 185A (generally mechanic 185) remains safely positioned while working on top of elevator car 103. Shaft 117 may have a pit 180, which has a ladder 195 extending from an access door 190 to the pit floor 180A. Access door 190 may also serve as an access point for the first (or lower) floor 125 of elevator car 103. Second mechanic 185B can access the pit via ladder 195.

[0036] Multiple sensors (totaling 200) can be used to detect the presence of the mechanic 185. Multiple sensors may be present, including but not limited to first, second, and third sensors 200A, 200B, and 200C mounted on the safety railing 103B (but mounting fewer or more sensors on the railing is within the scope of this embodiment) and a fourth sensor 200D in the pit 180 and at the ladder 195 (but different placement of sensors in the pit and / or the use of additional sensors in the pit is within the scope of this embodiment).

[0037] Regarding the pit, there may also be sensors located on the walls of the pit (near the corners) that scan the area parallel to the pit floor to detect the presence of the mechanic. At the top of the car, there may be at least one sensor configured to locate the counterweight; this may or may not be one of the same sensors scanning for the presence of the mechanic. A second beam can be used during setup to ensure the counterweight passes within its field of view.

[0038] Sensor data 201 can be transmitted to controller 115 in control room 121 via a connection on wireless network 150 (or wired network) established between sensor 200 and controller 115. Controller 115 can optionally be integrated into elevator car 103. If sensor data 201 indicates the presence of mechanic 185 (whether on the top 103A of elevator car 103 or on the pit ladder 195), controller 115 can stop elevator car 103 or put elevator car 103 into maintenance mode, which will result in a speed reduction.

[0039] In one embodiment, another control module (one for the top of the car and another for the pit area) is configured to communicate with sensors and place the car in a safe state by disengaging the safety chain. For simplicity, reference to controller 115 herein should include the independent actions of the control module. Controller 115's decisions may depend on the relative positioning of the car 103, mechanic 185, counterweight 105, and pit 180.

[0040] Sensor 200 may be a LiDAR (Light Detection and Ranging) sensor. Using a LiDAR sensor, laser light is emitted from a source (emitter) and reflected from an object. The reflected light is detected by a system receiver, and time-of-flight (TOF) is used to develop a distance map of the object. Sensor 200 emits corresponding infrared (IR) beams, collectively 205, including first to fourth IR beams 205A-205D emitted from some of the sensors 200. First to third IR beams 205A-205C may extend above the top 103A of the elevator car 103, and a fourth IR beam 205B may extend along the steps 195A of the hoistway 195.

[0041] For the sensors 200 to operate accurately, the IR beams 205 should be guided along a predetermined path. For example, the first to third IR beams 205A-205C should extend above and parallel to the top 103A of the elevator car 103. The fourth IR beam 205D should extend parallel to the steps 195 so that it is adjacent to each step 195A. If the IR beams 205 from different sensors 200 follow a path that is inclined compared to the predetermined path, the sensors 200 may miss the mechanics 185, thus affecting the controller 115's ability to correctly control the elevator car 103.

[0042] Go to Figure 2 A shows a sensor 200. The sensor 200 has a housing 210 extending from a front portion 210A to a rear portion 210B (the front portion 210A and rear portion 210B are spaced apart in depth), and extending between a first side 210C and a second side 210D (the first side 210C and the second side 210D are spaced apart in width). The housing 210 may define a generally rectangular box. The housing 210 may have a transparent cover glass 215 defining the front portion 210A of the housing 210, through which a light beam 205 is emitted and received. Within the housing 210 are a light beam emitting member (generally 220) adjacent to the first side 210C and a light beam receiving member (generally 230) adjacent to the second side 210D.

[0043] From the rear portion 210B to the front portion 210A of the housing 210, the beam emitting member 220 may include an NIR (near-infrared)-LD (laser diode) (generally an IR laser) 220A that generates an emitted (or first) beam 205E along a first path 205E1, an emitter-side (or first) lens 220B, and a beam expander 220C, which may be a diffractive optical element (DOE) or a diffuser that expands the emitted beam 205E by a predetermined amount. The receiving member 230, from the front portion 210A to the rear portion 210B of the housing 210, may include a receiver-side (or second) lens 230A for focusing the received beam 205R, an optical filter 230B, and a detector array 230C, which may include a photodiode, which may be an ADP (avalanche photodiode) or a CMOS (complementary metal-oxide-semiconductor).

[0044] like Figure 2As shown in Figure B, the beam emitting member 220 includes an IR laser 220A, a first lens 220B, and a beam expander 220C extending from the rear portion 210B of the housing 210 to the front portion 210A of the housing 210. According to an embodiment, between the first lens 220B and the beam expander 220C, a visible laser diode (VLD) 250 (or visible beam emitter) emits a reference (or second) beam 260 of visible light along a second path 260A that is not aligned (misaligned) with the first path 205A1. A beam guide 270 (which may be a dichroic mirror) positioned along the first path 205E1 and at an angle 280 (or a first angle) to the second path 260A aligns the reference beam 260 so that it is coaxial or parallel to the emitted beam 205E and guides it out from the front portion 210A of the housing 210. The reflector 270 is configured, for example, using a suitable coating, to allow the transmission of infrared light and the reflection of visible light.

[0045] VLD 250 can be located anywhere within the first side 210C of housing 210, where the beam emitting member 220 is situated, as long as it does not interfere with the operation of the beam emitting member 220. As indicated, beam guide 270 is positioned relative to the emitted beam 205E at a first angle (or angle) 280 such that, regardless of where VLD 250 is located within the first side 210C of housing 210, reference beam 260 is coaxial with or parallel to the emitted beam 205E. As shown, VLD 250 is closer to the first side 210C of housing 210 than beam emitting member 220 and is oriented such that reference beam 260 is perpendicular to emitted beam 205E when it irradiates beam guide 270. With this configuration, beam guide 270 is at a forty-five-degree angle 280 to emitted beam 205E, but this is not intended to limit the position or orientation of VLD 250, reference beam 260, or beam guide 270.

[0046] During operation, the reference beam 260 is visible, while the emitted beam 205E is invisible. Therefore, the reference beam 260 is used to precisely orient the sensor 200 on the top 103A of the elevator car 103 and at the pit ladder 195. This provides improved accuracy for the sensor 200 and thus better protection for the mechanic 185 responsible for the elevator system 101.

[0047] Go to Figure 3The flowchart illustrates a method for controlling elevator system 101. As shown in block 305, the method includes confirming the alignment of one or more sensors 200 relative to the top 103A of elevator car 130 by visually inspecting whether a second beam 260 emitted from one or more sensors 200 extends above and parallel to the top 103A of elevator car 103. As shown in block 310, the method includes monitoring sensor data 201 from one or more sensors 200 located on the top 103A of elevator car 103 via controller 115, wherein sensor data 201 indicates that an object, such as a mechanic 185, has been detected on the top 103A of elevator car 103. As shown in block 320, the method includes, upon determining that sensor data 201 indicates that an object has been detected on the top 103A of elevator car 103, controller 115 stopping elevator car 103A or putting elevator car 103A into maintenance mode. Go to Figure 4 The flowchart illustrates a method for controlling elevator system 101. As shown in block 405, the method includes confirming the alignment of one or more sensors 200 relative to the pit ladder 195 by visually inspecting whether a second beam 260 emitted from one or more sensors 200 is along the pit ladder 195 and adjacent to the steps 195A of the pit ladder 195. As shown in block 410, the method includes monitoring sensor data 201 from one or more sensors 200 located in the pit 180 of the hoistway 117 via controller 115, the sensor data 201 indicating that an object, such as a mechanic 185, has been detected on the pit ladder 195 located within the pit 180. As shown in block 420, the method includes, upon determining that sensor data 201 indicates that an object has been detected on the pit ladder 195, controller 115 stopping elevator car 103 or operating elevator car 103 in maintenance mode.

[0048] The above embodiments provide a system that projects a reference (alignment) beam from the same transmission optics as the LiDAR sensor itself. This is achieved by inserting a dichroic mirror (i.e., a dichroic beam splitter or filter) at, for example, a 45-degree angle into the path of the IR light transmission beam and providing a second visible light source, for example, perpendicular to the original beam that is also aligned with the same dichroic mirror. The mirror is configured to allow for the transmission of IR light and the reflection of visible light. In this way, the two light sources can be aligned into a single, coaxial, or parallel transmission path, which visually informs the mechanic where the LiDAR sensor is aligned.

[0049] The advantages of this embodiment include reduced time spent by mechanics performing alignment without visible guidance. The embodiment allows for relatively simple checking of alignment during maintenance. The embodiment allows for precise alignment with a LiDAR light source. The embodiment eliminates the need for a separate alignment device, which would incur additional costs and may be less accurate.

[0050] The wireless connections identified above can apply protocols including Local Area Network (LAN, or WLAN of wireless LAN) protocols and / or Private Area Network (PAN) protocols. LAN protocols include WiFi technology, which is based on the Institute of Electrical and Electronics Engineers (IEEE) Section 802.11 standard. PAN protocols include, for example, Bluetooth Low Energy (BTLE), a wireless technology standard designed and marketed by the Bluetooth Special Interest Group (SIG) for exchanging data over short distances using short-wavelength radio waves. PAN protocols also include Zigbee, a technology based on the IEEE Section 802.15.4 protocol, representing a set of advanced communication protocols for creating personal area networks with small, low-power digital radios to meet low-power, low-bandwidth requirements. Such protocols also include Z-Wave, a wireless communication protocol supported by the Z-Wave Alliance that uses a mesh network to communicate between devices (such as appliances) using low-energy radio waves, thus allowing for wireless control.

[0051] Other applicable protocols include Low Power WAN (LPWAN), a type of wireless wide area network (WAN) designed to allow long-distance communication at low bit rates, enabling terminal devices to operate on battery power for extended periods (years). Long Range WAN (LoRaWAN) is an LPWAN maintained by the LoRa Alliance and is a Media Access Control (MAC) layer protocol used to relay management and application messages between network servers and application servers accordingly. Such wireless connectivity can also include Radio Frequency Identification (RFID) technology for communication with integrated chips (ICs), such as those on RFID smart cards. Furthermore, Sub-1GHz RF devices operate in the ISM (Industrial, Scientific, and Medical) spectrum band below Sub-1GHz—typically in the 769-935MHz, 315MHz, and 468MHz frequency ranges. This sub-1GHz spectrum band is particularly useful for RFIoT (Internet of Things) applications. Other LPWAN-IoT technologies include Narrowband IoT (NB-IoT) and Class M1 IoT (CatM1-IoT). Wireless communication used in the disclosed systems may include cellular technologies, such as 2G / 3G / 4G (and so on). The above is not intended to limit the scope of applicable wireless technologies.

[0052] The wired connections identified above may include connections (cables / interfaces) under RS ​​(Recommended Standard)-422 (also known as TIA / EIA-422), a technical standard supported by the Telecommunications Industry Association (TIA) and initiated by the Electronic Industries Alliance (EIA), which specifies the electrical characteristics of digital signal circuits. Wired connections may also include connections (cables / interfaces) under the RS-232 standard for serial communication data transmission, which formally defines the signal connection between DTE (Data Terminal Equipment) (such as computer terminals) and DCE (Data Circuit Termination Equipment or Data Communication Equipment) (such as modems). Wired connections may also include connections (cables / interfaces) under the Modbus serial communication protocol managed by the Modbus organization. Modbus is a server / client protocol designed for use with programmable logic controllers (PLCs) and is a common method for connecting industrial electronic devices. Wireless connections may also include connectors (cables / interfaces) under the PROFIbus (Process Fieldbus) standard managed by PROFIBUS & PROFINET International (PI). PROFIBUS is a standard for fieldbus communication in automation technology, publicly released as part of IEC (International Electrotechnical Commission) 61158. Wired communication can also be achieved via Controller Area Network (CAN) bus. CAN is a vehicle bus standard that allows microcontrollers and devices to communicate with each other in applications without a master. CAN is a message-based protocol published by the International Organization for Standardization (ISO). The above is not intended to limit the scope of applicable wired technologies.

[0053] As indicated, when data is transmitted over a network between terminal processors, the data may be transmitted in its raw form, or it may be processed, wholly or partially, at one of the terminal processors or intermediate processors (e.g., at a cloud service or other processor). The data may be parsed, partially or wholly processed or compiled at any processor, and then it may be concatenated together or maintained as a separate data packet.

[0054] Each processor identified herein can be, but is not limited to, a single-processor or multi-processor system in a variety of possible architectures, including homogeneous or heterogeneous field-programmable gate arrays (FPGAs), central processing units (CPUs), application-specific integrated circuits (ASICs), digital signal processors (DSPs), or graphics processing units (GPUs) hardware. Memory identified herein can be, but is not limited to, random access memory (RAM), read-only memory (ROM), or other electronic, optical, magnetic, or any other computer-readable medium. Embodiments can take the form of processes implemented by a processor and means for practicing those processes, such as a processor. Embodiments can also take the form of computer code-based modules, such as computer program code containing instructions (e.g., a computer program product), the instructions being embodied in a tangible medium (e.g., a non-transitory computer-readable medium), such as a floppy disk, CD-ROM, hard disk drive, processor registers as firmware, or any other non-transitory computer-readable medium, wherein when the computer program code is loaded into a computer and executed by the computer, the computer becomes means for practicing the embodiment. The embodiments may also take the form of computer program code, for example, whether stored in a storage medium, loaded into a computer and / or executed by a computer, or transmitted via some transmission medium, such as by wires or cables, by optical fibers, or via electromagnetic radiation, wherein when the computer program code is loaded into and executed by the computer, the computer becomes an apparatus for practicing the exemplary embodiments. When implemented on a general-purpose microprocessor, the computer program code segments configure the microprocessor to create specific logic circuits.

[0055] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The term “about” is intended to include the degree of error associated with a measurement based on a specific quantity and / or manufacturing tolerance of the equipment available at the time of filing. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that the terms “comprising” and / or “including” as used in this specification specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

Claims

1. A sensor, comprising: A housing extending from the front to the rear, wherein the front portion has a transparent cover glass; An infrared (IR) beam emitter within the housing emits a first beam along a first path; A visible beam emitter within the housing emits a second beam along a second path that is not consistent with the first path; as well as A beam guide within the housing engages the first beam and the second beam such that the first beam and the second beam are coaxial or parallel and exit the front portion of the housing.

2. The sensor according to claim 1, wherein The IR beam emitter is a near-infrared laser diode (NIR-LD) that emits the first beam along the first path, wherein the first path is directed toward the front of the housing; The visible beam emitter is a visible laser diode (VLD), which emits the second beam along the second path; and The beam guide is a dichroic mirror disposed along the first path and at a first angle to the second path, such that the first beam and the second beam are coaxial or parallel and exit the front portion of the housing.

3. The sensor according to claim 2, wherein, The beam guide is configured to allow the transmission of the first beam and the reflection of the second beam.

4. The sensor according to claim 3, wherein, The sensor includes: A beam emitting member on a first side of the housing, the beam emitting member including the IR beam emitter, a first lens, and a beam expander from the rear to the front of the housing; and A beam receiving member on the second side of the housing, extending from the front to the rear of the housing, includes a second lens, an optical filter, and a detector array.

5. The sensor according to claim 4, wherein, The beam expander is a diffractive optical element (DOE) or a diffuser.

6. The sensor according to claim 4, wherein, The detector array includes photodiodes.

7. The sensor according to claim 6, wherein, The photodiode is an avalanche photodiode (APD) or a complementary metal-oxide-semiconductor (CMOS).

8. The sensor according to claim 4, wherein, The VLD is located on the first side of the housing, adjacent to the beam emitting member.

9. The sensor according to claim 8, wherein, The VLD is configured such that the second path is perpendicular to the first path before engaging the beam guide.

10. An elevator system, wherein: An elevator car having a car top and a guardrail mounted to the car top, wherein one or more sensors according to claim 1 are mounted on the guardrail; or One or more of the sensors are fixed to a corner of the car roof or to another surface near the edge of the car roof.

11. The elevator system according to claim 10, comprising Multiple sensors are mounted on the guardrail and distributed around the top of the elevator car.

12. The elevator system according to claim 10, comprising: The elevator controller is configured as follows: Receive sensor data from the one or more sensors; When the sensor data indicates that an object has been detected on the top of the elevator car, the elevator car is stopped or operated in maintenance mode.

13. The elevator system according to claim 12, wherein: The elevator controller is configured to communicate with the one or more of the sensors via a wireless network; or Another control module is configured to communicate with the sensor and place the car in a safe state by opening the safety chain.

14. An elevator system, comprising: The shaft of the limited pit; A pit ladder with steps; as well as One or more sensors according to claim 1 are mounted in the pit and configured such that an emitted beam from another sensor extends adjacent to each step of the pit ladder.

15. The elevator system according to claim 14, comprising The elevator controller is configured as follows: Receive sensor data from the one or more sensors; When the sensor data indicates that an object has been detected on the pit ladder, the elevator car of the system is stopped or the elevator car is operated in maintenance mode.

16. The elevator system according to claim 15, wherein, The elevator controller is configured to communicate with the one or more sensors via a wireless network.

17. A method for controlling an elevator system, comprising: The controller monitors sensor data from one or more sensors located on the top of the elevator car, the sensor data indicating that an object has been detected on the top of the elevator car. Each of the sensors includes: a housing extending from a front to a rear, wherein the front portion has a transparent cover glass; an infrared (IR) beam emitter within the housing that emits a first beam along a first path; a visible beam emitter within the housing that emits a second beam along a second path inconsistent with the first path; and a beam guide within the housing that engages the first and second beams such that the first and second beams are coaxial or parallel and exit from the front portion of the housing; and When the sensor data indicates that the object has been detected on the top of the elevator car, the elevator car is stopped or operated in maintenance mode.

18. The method of claim 17, comprising: The alignment of the one or more sensors with respect to the top of the elevator car is confirmed by visually inspecting whether the second beam emitted from the one or more sensors extends above and parallel to the top of the elevator car.

19. A method for controlling an elevator system, comprising: The controller monitors sensor data from one or more sensors located in the pit within the shaft, the sensor data indicating that an object has been detected on the pit ladder located within the pit. Each sensor includes: a housing extending from a front to a rear, wherein the front portion has a transparent cover glass; an infrared (IR) beam emitter within the housing that emits a first beam along a first path; a visible beam emitter within the housing that emits a second beam along a second path inconsistent with the first path; and a beam guide within the housing that engages the first beam and the second beam such that the first beam and the second beam are coaxial or parallel and exit from the front portion of the housing; and When the sensor data indicates that the object has been detected on the pit ladder, the elevator car of the system is stopped or the elevator car is operated in maintenance mode.

20. The method of claim 19, comprising: The alignment of the one or more sensors relative to the pit ladder is confirmed by visually inspecting whether the second beam emitted from the one or more sensors is along the pit ladder and adjacent to the steps of the pit ladder.

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