Patent Publication Number: US-2023150805-A1

Title: Lifting System with Indoor Positioning System and Method Therefor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 15/278,444 filed Sep. 28, 2016, which claims priority to Netherlands Patent Application No. 2015532 filed Sep. 30, 2015. The disclosure of each of these documents is hereby incorporated in its entirely by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a lifting system, more specifically a vehicle lifting system. In general, lifting systems are specifically used for lifting passenger cars, trucks, busses, or other vehicles and may involve a system comprising one or more moveable lifts or lifting devices, such as (mobile) lifting columns, lifting columns of the two-post lift type with pivoting support arms, the four-post lift type with runways, the mobile type, in-ground lifts etc. 
     Description of the Related Art 
     Conventional lifting systems comprise a frame with a carrier that is connected to a drive for moving the carrier upwards and downwards. In the ascent mode, hydraulic oil is pumped to a cylinder for lifting the carrier and, therefore, the vehicle. In the descent mode, the carrier with the vehicle is lowered and hydraulic oil returns to the reservoir. Such prior art lifting system is disclosed in U.S. Patent Application Publication No. 2006/0182563, which is incorporated herein by reference. Such lifting systems as well as other lifting systems require the use of a number of sensors, such as height sensors, to enable correct operation of the lifting system. This involves integration of these sensors and related components into the control system. 
     An object of the invention is to reduce complexity of vehicle lifting systems and/or to improve safety when working with these vehicle lifting systems. 
     SUMMARY OF THE INVENTION 
     This object is achieved with a lifting system for lifting a vehicle according to the invention, the lifting system comprising: one or more lifting devices, each comprising: a frame with a carrier configured for carrying the vehicle; a drive for driving each carrier of the one or more lifting devices in at least one of the ascent or descent of the carrier; and a controller comprising an indoor positioning system such that the controller determines the location and the height of the carrier in at least one of the ascent or descent of the carrier of the one or more lifting devices, and wherein the controller comprises a remote control, wherein the controller further comprising a monitoring system configured for monitoring a safety zone, wherein the monitoring system monitors a three-dimensional zone, and wherein the safety zone comprises an inner zone, an intermediate zone and an outer zone. 
     The lifting system according to the invention specifically relates to a vehicle lifting system using a number of lifting devices, including lifting columns, mobile lifting columns, lifting columns of the two-post lift type with pivoting support arms, the four-posts lift type with runways, in-ground lifts, for example. In the context of the present invention the carrier relates to the moving parts of the lifting device when lifting the vehicle. This carrier is driven by a drive, such as a hydraulic drive, pneumatic drive and/or electric drive. 
     The lifting system according to the present invention comprises a controller with an indoor positioning system. The controller is provided to control the vehicle lifting with the lifting device of the present invention, optionally with the lifting device being included in a group of lifting devices that jointly lift the vehicle, for example in case of mobile lifting columns. Such controller can be operated by a user, also referred to as operator, at the desired location. Such controller may further relate to a so-called central controller that is capable of controlling several lifting devices. The controller preferably is or comprises a remote control that may relate to a dedicated remote control or an existing apparatus such as a tablet or mobile phone that is provided with the relevant software. Preferably, such (central) controller comprises a wireless transmitter and receiver to enable a wireless control of the lifting device by a user. This further enhances the flexibility for a user when lifting a vehicle. Optionally, the remote is switched off when not being used for a pre-determined time period, for example 2 minutes or any other suitable time period. Also optionally, the transmission power of the remote control can be designed or controlled to limit the distance of operation between the remote control and the lifting device. This prevents accidental instructing the lifting device to move and, thereby, improves the overall safety of working with the lifting device. 
     According to the invention the controller of the lifting device comprises a wireless communication coupling. This wireless communication coupling is configured for coupling the lifting device to a further lifting device to enable jointly lifting the vehicle. The one or more lifting devices may relate to different types of lifting devices, such as lifting columns, mobile lifting columns, lifting columns of the two-post lift type with pivoting support arms, the four-posts lift type with runways, in-ground lifts. Providing the wireless communication coupling enables a joint control of the first and further lifting device when lifting a vehicle, for example. This can be used in different situations, including lifting trains or road trains, or articulated/accordion buses with two or more four-post lifts or sky lifts or other lifting devices, for example. By providing the wireless communication coupling it is no longer required to connect the lifting devices with a communication cable. This further improves the overall flexibility when working with the lifting device and lifting system according to the present invention. In addition, the wireless communication coupling obviates the safety hazard of cables across the workshop floor. In a presently preferred embodiment the remote control uses a RS485 port with a transmitter/receiver. Furthermore, in a presently preferred embodiment the remote control is capable of controlling one of the lifting devices alone or jointly with the other lifting devices. This provides a flexible and effective control of a lifting operation. It will be understood that other communication possibilities can also be envisaged in according to the present invention. 
     The lifting device according to the present invention further comprises an activator that is configured for searching and/or coupling the controller to the lifting device. This activator is used to find and/or couple the controller to the lifting device. This activator comprises a RFID-system for the searching and/or coupling of the controller to the lifting device. Such radio-frequency identification (RFID) system makes use of electromagnetic signals and comprises a RFID-reader that is preferably capable of triggering with a pulse on a RFID-tag. Such tag transmits relevant data back to the RFID-reader such as an identification number. Such RFID-tag typically comprises a chip for processing information and an antenna for receiving and/or transmitting data that are preferably provided on a substrate. These RFID-tags can be passive or active involving a battery. In the presently preferred embodiments of the invention an active RFID-tag is used to improve data transmission. The RFID-reader waits for receipt of a signal from a RFID-tag or may (periodically) transmit a signal when switching an RFID-tag. The RFID-system preferably operates in the frequency band between 120 kHz and 10 GHz, although it is presently preferred to use the ultra-high frequency (UHF) bands. In the context of the present invention it is noted that in certain embodiments of the invention the RFID-system may also operate on a Terahertz frequency to which is also referred as a TFID-system. 
     The RFID-system enables a user to position the RFID-reader and RFID-tag at a certain distance as the tag can be read at a distance from the reader. This improves flexibility for a user when using the lifting device of the present invention as no physical contact between the tag and the reader is required. Furthermore, there is no specific need to present the tag to the lifting device and/or enter access or validation codes or passwords. 
     The RFID-system is particularly useful for searching and/or coupling with a lifting device, optionally with two or more different lifting devices, and provide an automatic identification. Optionally, a user must provide an individual identification to the RFID-system and/or control of the lifting device to enable its use. Thereafter, the RFID-system enables coupling to one or more lifting devices. It is noted that in operation the lifting device can make use of wireless communication that optionally uses Wi-Fi, Bluetooth, Zigbee or other suitable communication protocol. 
     In a presently preferred embodiment the operation from a controller on the lifting device itself is blocked after coupling the controller. This reduces the risk of safety conflicts. Preferably, the (local) controller on the lifting device itself is unlocked after signing out or logging off the (remote) control. Optionally, when controlling the lifting device with a remote control a signal is generated for actually moving the lifting device. Such signal may involve a sound and/or light signal. 
     Preferably, the RFID-system is capable of coupling with different types of lifting devices. This provides the advantage of using the RFID-system and the (central) controller in cooperation with different types of lifting devices such as mobile lifting column, in-ground lifts, or other suitable lifting devices. This further enables a user to rely on a single (remote) control for operation of several lifting devices. Furthermore, the (remote) control can be directly linked to a specific user. This further increases the flexibility when lifting a vehicle. 
     In a preferred embodiment of the invention the remote control comprises a wireless charger. 
     Providing the remote control with a wireless charger enables wirelessly charging the battery of the remote control, thereby guaranteeing the operation of the remote control and (parts of) the RFID-system. 
     As a further advantage this renders it possible to optionally provide a gastight remote control in a presently preferred embodiment of the invention. Providing such an optional gastight remote control improves the overall safety when working with the lifting device. In particular, such remote control provides additional safety in the presence of fuel gases and/or exhaust/compression gases. In addition to the safety improvement this also improves the operational flexibility. 
     In a presently preferred embodiment of the present invention the lifting device is provided with a RFID-reader and the (remote) control is provided with an RFID-tag. It will be understood that in an alternative embodiment the (remote) control is provided with the RFID-reader and the lifting device provided with an RFID-tag. 
     In a presently preferred embodiment of the invention the (remote) control can be deactivated with a de-activator. 
     By providing a de-activator the controller is deactivated for use with a specific lifting device. For example, the (remote) control can be deactivated in case of an unsafe situation. This increases the overall safety when lifting a vehicle. 
     The de-activator may apply an inactive time period, such that after this specific time period, wherein the controller is inactive, also referred to as a time-out, the (remote) control is deactivated. For a further operation with this controlling a new coupling and/or unlocking is required. This improves safety when working with the lifting device of the present invention. An inactive time period can be a period of 1 to 2 minutes, for example. It will be understood that other time intervals can also be envisaged in accordance with the present invention. 
     In addition, or as an alternative, the activator may also comprise an inactive distance. In such embodiment, when the control is positioned at a distance from the lifting device larger than the inactive distance, the de-activator stops the coupling of the controller with the lifting device. For further operation a new coupling and/or unlocking is required. An inactive distance can be 3 meters, 5 meters, 10 meters or any other suitable distance. 
     In a presently preferred embodiment the RFID-system is used to determine the actual distance between the controller and the lifting device. This provides an effective means to compare the actual distance with the inactive distance and to determine the operation of the controller in association with the lifting device. 
     As an alternative or in addition to the actual distance measurement with the RFID-system the transmitting power of the controller can be adjusted to send a maximum operational distance of 5 m to 10 m, for example. This guarantees that a user accidentally operates the lifting device when being on a different location and/or at a large distance from the lifting device. 
     Preferably, the de-activator is adjustable. For example, an adjustment is possible of the inactive time period and/or the inactive distance and/or the frequency of a check by the de-activator. This enables adjustment of the de-activator and the lifting device in view of the specific circumstances, such as the presence of other lifting devices in the near vicinity of the controlled lifting device. 
     In a presently preferred embodiment of the invention the controller comprises a signaling device. 
     By providing a signaling device the (immediate) vicinity of the lifting device can be given a warning signal when the controller starts operation and/or starts an actual lifting or lowering of a vehicle. This improves safety when working with the lifting device. The signaling device may provide an acoustic and/or other suitable signal. For example, the signal may be an indicative signal of 1 to 2 seconds indicating movement of the carrier. Alternatively, or in addition thereto, a signal can be generated from the lifting device itself, optionally involving a light signal. Preferably, no acoustic or other signal is generated within a time interval after the last signal. This enables continuous operation of the lifting device. Such time interval is 10 seconds, for example. 
     In a presently preferred embodiment of the invention the (remote) controller transmits its data to the lifting device. In case multiple lifting devices such as mobile lifting columns are coupled in a set or lifting system the remote control preferably transmits its data to a specific column, to which can also be referred to as master column that uses the data. The receiving lifting device uses the data to control the lifting operation. For safety reasons the lifting device communicates periodically with the remote control to continue this specific configuration of the lifting device with remote control. This time period is one signal per second, for example. In case multiple lifting devices are coupled together, the receiving lifting device that is coupled to the (remote) control preferably transmits the data to the other devices. This is specifically relevant for mobile lifting columns and in-ground lifting devices. In such cases a selection of lifting devices is optionally performed with one of these lifting devices and/or with the use of the remote control. 
     As an optional feature, the indoor positioning system is capable of communicating with one or more transponders, also referred to as transmitter and responder. Such transponders are also optional. The transponder transmits a message in response to a received message. The indoor positioning system is capable of locating the lifting device, and more specifically the carrier of the lifting device, inside a building, using radio waves, magnetic fields, acoustic signals or other means of transferring information. Possibly, a combination of signals can be applied. With the use of optical, radio or acoustic technologies, or other convenient technologies, the position and height of the carrier can be determined. Preferably, at least three independent measurements are used by the control system to determine the location and height of the carrier involving the use of trilateration. 
     The transponders may relate to so-called active transponders that are provided with an energy supply such as a battery or power supply. Also, transponders may relate to so-called passive transponders that receive the required energy from the received signal. An indoor positioning system using Wi-Fi signals is also referred to as a Wi-Fi-based positioning system. Also, blue tooth and other signals can be used in addition or as an alternative. Alternatively, or in combination with the aforementioned active and/or passive transponders, other devices acting as transponder can be applied. In the context of the present invention a transponder is a device that is capable of generating or forwarding a signal indicative for its location (and height), preferably in response to an interrogating (received) signal. 
     By providing the transponder on or at the carrier, both location and height of the carrier can be determined with the indoor positioning system of the controller. This obviates the need for separate height sensors, as the transponder can be used for both location determination and for height measurement of the carrier during the lifting operation. This renders the lifting system less complex. Location of lifting devices is used when selecting lifting devices for a lifting system. This specifically relates to mobile lifting column, for example. The height measurement is relevant for all types of lifting devices. 
     As an example, in an embodiment of a lifting system according to the invention, at least two lifting columns are being used as lifting devices. In fact, often four lifting columns are being used. When lifting a vehicle, controlling the actual height of the carriers of these separate lifting columns and optionally also the moving speed of the carrier that carries (part of) the vehicle when lifting a vehicle requires synchronization. The controller preferably synchronizes the height of the separate carriers in the ascent mode using, for example, a measurement signal generated by the indoor positioning system. In case one of the carriers has moved too fast in the ascent mode and is too high as compared to the other carriers of the other lifting columns the power supply to this carrier is either directly or indirectly lowered so that the other carriers can catch up or, alternatively, the power supply to the other carriers is either directly or indirectly increased so that the other carriers can catch up. In the descent mode, it is also important that the height of the carriers between the several lifting columns is synchronized. Therefore, in case one of these carriers has moved too slowly, its power supply is increased in order for this carrier to catch up with the other carriers or, alternatively, the power supply to the other carriers is either directly or indirectly lowered so that the other carriers can catch up. 
     Other types of lifting devices involve a similar (synchronization) operation and may also benefit from the use of the indoor positioning system. 
     Preferably, the controller further comprises an orientation detector. With the orientation detector, the orientation of the lifting device can be established with the indoor positioning system. For example, the orientation of a lifting device is relevant when using mobile lifting columns that can be repositioned in a building relative to the vehicle to be lifted. In one of the embodiments according to the present invention, the orientation detector is a further transponder. Alternatively or in addition thereto, the orientation detector comprises an electronic compass or so-called magnetometer. An example of such magnetometer is known from consumer devices such as mobile phones and tablet computers. 
     In a presently preferred embodiment according to the present invention the controller further comprises a monitoring system configured for monitoring a safety zone. 
     By providing a monitoring system, the lifting system can be protected with a safety zone. This safety zone defines an area or zone that is monitored using one or more sensors, optionally including transponders. When a person and/or object enters the safety zone and/or is present in the safety zone, movement of the carrier is optionally blocked by the controller. This increases safety when working with the system according to the present invention. This safety zone preferably is a three-dimensional zone that can be shaped as a wall, circle, sphere, dome, or any other appropriate shape. The safety zone can be shaped with one or more boundaries. For example, in one embodiment the safety zone comprises an inner working zone and an outer non-working zone. In another embodiment the safety zone comprising an inner non-working zone, for example directly under the lifting device, an intermediate working zone, and an outer non-working zone. It will be understood that other examples of the shape and size of the safety zone can be envisaged. 
     In a further preferred embodiment according to the present invention the monitoring system comprises an adaptation system that is configured for adjusting the boundaries of the safety zone. 
     Preferably, the monitoring system comprises an adaptation system configured for adjusting the boundaries of the safety zone. In a presently preferred embodiment, the adaptation system responds to a height measurement of the carrier. The adaptation system may adjust the boundaries of the safety zone, rendering the safety zone dynamic in size and/or shape. Other parameters may also be used by adaptation system, such as the presence and/or type of vehicle that is lifted and the distance to other systems and other sets of lifting devices. Therefore, the lifting system may comprise a vehicle detector that is capable of detecting the presence of a vehicle and preferably the vehicle type. 
     As an example, the adaptation system enables adjustment in response to the actual height of the carrier and/or the presence of a vehicle in the lifting system of the present invention. The safety zone may have a (dynamic) working/operational zone wherein an operator may perform operations with the lifting system. For example, in some cases, in a zone directly under and/or around the lifting system operating the lifting system with a remote control is prohibited. For example, in an in-ground lift the remote control is enabled to operate under the vehicle when the carrier is below a height of about 30 cm. This enables positioning the carriers, for example. This (safety) zone is (dynamically) established in response to a height measurement to prevent a person from getting under the vehicle when moving the carrier, for example. In a further example, the outer boundary of the safety zone defines the maximum distance from the lifting system an operator may use the lifting system. In one of the embodiments, this results in a dynamic safety zone with an inner boundary and an outer boundary. This safety zone can be shaped as a wall, block, three-dimensional shape, dome shape, and other appropriate shapes. 
     In a further preferred embodiment according to the present invention, the monitoring system further comprises a warning system configured for providing a warning signal and/or control signal in response to a person and/or object provided with a transponder entering and/or being in the safety zone. 
     By providing a warning system, appropriate warning and/or control signals can be generated. A warning signal can be provided to an operator, for example with a mobile device such as a phone or tablet computer. Also, a warning can be provided to a supervisor or other person or system. Alternatively or in addition thereto, a control signal can be provided to the controller and optionally the lifting system can be blocked until the person and/or object has been removed from the safety zone, for example. 
     In a further preferred embodiment according to the present invention the monitoring system further comprises an engagement safety system configured for monitoring correct engagement of the carrier to the vehicle when lifting the vehicle. 
     By providing an engagement safety system a correct engagement of the carrier to the vehicle, for example to the wheel axles, wheels or other engagement area of the vehicle can be monitored. In case of an incorrect engagement, the lifting system can be blocked by the controller. The engagement safety system may use a camera or other sensing device for monitoring the engagement. The transponder can be used by the controller to establish that the carrier is indeed blocked in case of a warning. This increases the overall safety of the lifting system according to the present invention. 
     Preferably, the monitoring system further also comprises a descent safety system configured for monitoring a safe descent of the carrier. This is for example advantageously applied to an in-ground lifting system of a fully flush-mounted type. The correct location can be determined by the controller using the transponder on the carrier of the indoor positioning system, for example. For example, such flush-mounted type in-ground lift is described in U.S. Pat. No. 8,523,146, which is incorporated herein by reference. Also, in a presently preferred embodiment of the present invention it is possible that the controller of the lifting system uses the transponders to position the carrier correctly in a descent mode. Correctly positioning the lifting device is optionally done automatically by the controller. 
     In a further preferred embodiment according to the present invention, the lifting system further comprises a release system for releasing the carrier and enabling the lifting system to lift the vehicle. 
     By providing a release system, the lifting system can be enabled to lift a vehicle. Preferably, the release system is controlled in cooperation with the monitoring system. Optionally, the release system is controlled by the controller in response to payment instructions, identification and/or authorization procedures. The release system may involve locking and/or unlocking means. This prevents undesired and/or unneeded lifts. In addition, this also enables direct debiting of the vehicle owner for the usage of the lifting system, providing a type of so-called pay-per-lift debiting system. Optionally, the release system receives a clearance signal of a clearance system after payment, identification and/or authorization to perform a number of lifting operations, optionally in a specific time period. 
     In a further preferred embodiment according to the present invention, the controller further comprises a remote control. 
     By providing a remote control, the operation of the lifting system is rendered more easy and effective for an operator. The remote control may relate to a mobile phone, tablet computer or other device. Preferably, the indoor positioning system also senses the location of the remote control and uses the information in the monitoring system, for example. This can be achieved by providing the remote control with a transponder of the indoor positioning system, for example. 
     In a further preferred embodiment according to the present invention, the lifting system comprises two or more sets of lifting devices, wherein each set is configured for lifting a vehicle, the lifting system further comprising a central controller. 
     By providing a central controller, the controller is capable of controlling multiple lifting systems and/or multiple sets of lifting devises. As an example, when a vehicle needs to be lifted, a set of (mobile) lifting columns is selected and is defined as a group. The central controller controls this group of lifting devices. Another group of lifting devices can also be controlled by the central controller independently. Optionally, the central controller instructs the adjustment system of the monitoring system to amend or adjust boundaries of the safety zone, taking into account the location of the different groups of lifting columns. Furthermore, the central controller may communicate with remote computers or computer systems for maintenance and repair, logistics, debiting etc. 
     Optionally, the central controller selects a set of lifting devices that is available and most convenient for a user. Next, the user can be provided with a suggested set of lifting devices that he only needs to approve. This prevents the user to contact each individual lifting device that needs to be selected. Optionally, the selection is automatically authorized and the specific set of lifting devices is directly ready for use. 
     In a further preferred embodiment according to the present invention, the lifting system further comprises one or more tools and/or accessories that comprise a transponder. 
     By providing tools and/or accessories with a transponder, the indoor positioning system is capable of determining the location of these tools and/or accessories. This information can be used in the safety system, for example. Furthermore, this information can be used by the controller for monitoring location (and height) of tools, such us wheel dollies, axle stands, transmission jacks etc., relative to the vehicle. Optionally, the controller locks the lifting system until the required tools and/or accessories are available on the desired location, for example. 
     As a further example, in case the remote control with transponders is below 460 mm or 18 inch from the work floor, the remote control can be blocked by the controller and it is no longer active in the lifting system. This contributes to an explosion-proof lifting system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages, features and details of the invention will be elucidated on the basis of preferred embodiments thereof, wherein reference is made to the accompanying drawings, in which: 
         FIG.  1    shows a lifting system with multiple groups of lifting devices and a central controller according to the present invention; 
         FIGS.  2 - 7    show alternative embodiments with different types of lifting devices according to the present invention; 
         FIG.  8    shows steps of a method of lifting a vehicle according to the present invention; and 
         FIG.  9    shows steps for a safety protocol while operating the lift according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. While the disclosure is described as having exemplary attributes and applications, the present disclosure can be further modified. This application is therefore intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice of those skilled in the art to which this disclosure pertains and which fall within the limits of the appended claims. Accordingly, the following description of certain embodiments and examples should be considered merely exemplary and not in any way limiting. 
     In the illustrated embodiment lifting system  2  ( FIG.  1   ) comprises two sets of mobile lifting columns  2   a ,  2   b . In the illustrated embodiment each set comprises four mobile lifting columns  4 . Lifting columns  4  lift passenger car  6  from ground  8 . Lifting columns  4  comprise foot  10  which can travel on running wheels  12  over ground surface  8  of for instance a floor of a garage or workshop. In the forks of foot  10  there is provided an additional running wheel (not shown). Lifting column  4  furthermore comprises mast  14 . Carrier  16  is moveable in upward and downward directions along mast  14 . Carrier  16  is driven by a motor  18  that is located in a housing of lifting column  4 . Motor  18  is supplied with power from the electrical grid, or by a battery that is provided on lifting column  4  in the same housing as motor  18 , or alternatively on foot  10  (not shown). Display unit  20  may provide the user with information about the lifting system. 
     In the illustrated embodiment lifting columns  4  are connected to central controller  22  by wireless communication means  24  on individual lifting column  4  and wireless communication means  26  on central controller  22 . Wireless communication means  24 ,  26  involve one or more transmitters and/or receivers. 
     The illustrated lifting system  2  includes at least two lifting columns  4 . Each of the lifting columns has at least one ascent mode and one descent mode, and is under the influence of central controller  22 . In the illustrated embodiment controller  22  is positioned centrally above lifting columns  4  assuring a good communication path between the individual lifting columns  4  and the central controller  22 . 
     Central controller  22  determines the desired control actions. This may involve receiving a measurement signal representing the actual height of a carrier of an individual lifting column that is measured with indoor positioning system  28 . In the illustrated embodiment, indoor positioning system  28  is incorporated in central controller  22 . Indoor positioning system  28  is capable of measuring position and/or speed of carrier  16 . In the illustrated embodiment indoor positioning system  28  comprises a transponder  28   a  and magnetometer  28   b  attached to carriers  16 , and a number of “satellites”  28   c  positioned in the vicinity of lifting system  2  and communicating with wired or wireless communication lines  28   d  with central controller  22 . 
     Central controller  22  detects height differences between lifting columns, calculates the required control actions with computing means  30 , such as a processor, for individual lifting columns, and communicates the control actions to the relevant individual lifting columns. In the illustrated embodiment battery  32  provides power to central controller  22 . Alternatively, or in addition, power is provided through connection  34  to the electrical grid. Data can be stored in memory/storage  36 . Central controller  22  is provided with a wired and/or wireless connection  38  to enable connection between communication module  39  of central controller  22  to internal and/or external networks, involving internal company networks for workshop control  40 , financial control  42  and maintenance  44 , for example, and optionally to external networks  46  of suppliers and/or customers, for example. 
     Remote control  48  is provided with additional transponder  50  to enable monitoring the position of remote control  48 . It will be understood that other tools and/or accessories can also be monitored by indoor positioning system  28 . 
     In the illustrated embodiment there is provided wireless functionality to communicate in one or more environments such as LAN, WAN, VPN intranet, internet etc. that are schematically shown in the illustrated embodiments. Display unit  20  is further provided with input/output ports, such as USB, SD card reader, smart phone communication possibilities etc. to improve the functionality. Display  20  and/or remote control  48  may provide warning signals to the user. 
     Optionally, central controller  22  is provided with a number of communicators/distributors  52 , such as an RF-host, that sends and/or receives signals  54  between lifting columns  4  and communicator  52 , and signals  56  between communicator/distributor  52  and central controller  22 . Communicators/distributors  52  provide additional robustness to the overall operation of the groups  2   a ,  2   b  of lifting columns  4 . 
     In a preferred embodiment, central controller  22  is provided with monitoring system  58  that defines safety zone  60  (for illustrative purposes safety zone  60  is illustrated in  FIG.  2   ). In the illustrated embodiment group,  2   a  is provided with an inner boundary surface or wall  62  and an outer boundary surface or wall  64 . The space between walls  62 ,  64  is working zone  66  wherein an operator is allowed to operate group  2   a . On the other side of surfaces or walls  62 ,  64 , operation is locked or not authorized. Safety zone can be applied to the different types of lifting devices in the illustrated or another suitable shape. 
     Preferably, central controller  22  ( FIG.  1   ) comprises adaptation system  68  that is capable of adjusting or adapting boundaries  62 ,  64  in directions A and B, respectively. Adaptation system  68  responds to indoor positioning system  28 . Furthermore, central controller  22  preferably comprises warning system  70  capable of sending a warning to a user or operator in case of a safety issue. For example, in case control of group  2   a  is activated outside working zone  66  a warning message is provided to remote control  48  and/or any other suitable device. Optionally, release system  72  locks and/or unlocks lifting columns  4  thereby locking and/or unlocking movement of carrier  16 . 
     It will be understood that other configurations/designs for safety zone  60  can be envisaged in accordance with the present invention. For example, for group  2   b  a dome-shaped safety zone  74  is illustrated. Optionally, a two-wall safety zone can be provided by monitoring system  58 . Other shapes can also be provided, including circular, spherical, donut shapes etc. Optionally, the boundaries are adjustable. 
     In the illustrated embodiment central controller  22  further comprises engagement system  76  and descent safety system  78 . Engagement system  76  may comprise camera  80  that monitors engagement of carrier  16  to vehicle  6 . Camera  80  may also operate as vehicle detector. Alternatively, separate cameras  80  and/or other appropriate sensing means are provided. Descent safety system  78  monitors descent of carrier  16  in relation to its position with indoor positioning system  28 . This enables lowering carrier  16  at a desired location. 
     In system  2 , a user optionally performs a selection of lifting columns  4  that are incorporated in a group  2   a ,  2   b  by selecting lifting columns with a key or card  82  or other means. Optionally, controller  22  selects most suitable lifting columns  4  with indoor positioning system  28  and presents the selection to the user. Preferably, the selected group of lifting columns  4  in system  2  is provided with user instructions on one of the lifting columns  4 , using display  20  and/or remote control  50 , for example. Transmitter/receivers  24 ,  26  provide the instructions to central system controller  22 . On a central level, controller  22  determines the individual control actions to be taken for all lifting columns  4  in system  2 . Transmitter/receivers  24 ,  26  provide the control actions from the central controller to the individual lifting column  4 . Information about the actual position of carrier  16  and/or other relevant data is measured by indoor positioning system  28  and the measurement data is provided to central controller  22  that determines if and what control actions are required. In the illustrated embodiment no direct communication between individual lifting columns  4  is required. This significantly contributes to the robustness of lifting system  2 . 
     Operation and control of a single group of lifting columns with a dedicated group controller is also possible in a similar manner as described for the two groups  2   a ,  2   b . Controller  22  is suitable for use with lifting systems comprising any number of lifting devices  4 , including systems having one, two, four or another number of columns  4 . The columns  4  may achieve lifting and lowering capability by any means known to those of skill in the art, including hydraulically, electrically, mechanically, and electromechanically. Lifting systems  2  that are compatible with the control system may be stationary and/or permanently affixed or attached to a certain location or may be mobile, capable of being transported via wheels or any other suitable means known to those in the art. With reference to the figures, like element numbers refer to the same element between drawings. 
     Next, examples will be given of the use of indoor positioning system  28  in combination with other types of lifting devices. It will be understood that also other embodiments according to the present invention can be envisaged. 
     For example, a four-post lifting system  102  ( FIG.  2   ) comprises four columns  104  carrying runways  106 . Preferably, each column  104  has one transponder  28   a  and compass  28   b . In the illustrated embodiment an indicator  110  with a green light  112  and a red light  114  is provided. Light  110  signals to the driver when vehicle  6  is positioned correctly relative to columns  104  and the vehicle  6  can be lifted. In case each column  104  is connected to indoor positioning system  28  the position of the carrier/runways  106  can be checked. This contributes to the overall safety of the lifting operation. 
     As a further example, lifting system  202  ( FIG.  3   ) comprises a so-called sky-lift configuration with four posts  204  carrying runways  206 . In the illustrated embodiment transponder  28   a  and compass  28   b  is provided for every post  204 . This enables the check on positioning of the carrier as described earlier by calculating the height of runways  206  from the orientation of posts  204 , for example. Optionally, transponder  28   a  is provided directly on or at runways  206 . A light  210  with green  212  and red  214  lights can be provided on wall  216  to indicate to the driver of vehicle  6  that the vehicle is positioned correctly or needs to be repositioned. 
     As an even further example, lifting system  302  ( FIG.  4   ) comprises a so-called two-post configuration with two posts  304  that are provided with carrier arms  306 . In the illustrated embodiment, to measure position and speed of carrier arms  306  transponder  28   a  is provided. This enables the check on positioning of arms  306  as described earlier. A light  310  with green  312  and red  314  lights can be provided to indicate to the driver of vehicle  6  that the vehicle is positioned correctly or needs to be repositioned. 
     Providing arms  306  with transponders  28   a  enables monitoring the position and level of extension of arms  306 . This enables dynamic adjustment of the maximum load, as a long arm reduces maximum load and a short arm increases maximum load. Load can be measured with load cell  316 . 
     In a further alternative embodiment lifting system  402  ( FIG.  5 A-B ) is of the in-ground lift type comprising stationary lifting column/device  404  and a moveable lifting column/device  406  that are located on or in floor  408 . The front lifting column/device  404  is provided in cassette or box  410  with a telescopic lifting cylinder  412 . On top of cylinder  412  there is provided carrier  414  with axle carriers  416 . In the illustrated embodiment wheel hatches or wheel recesses  418  are provided. Hatches/recesses  418  define the position of the front wheels of the vehicle. Furthermore, in the illustrated embodiment a hatch  420  is provided in front of the front lifting column/device  404  for maintenance, for example. 
     The moveable lifting column/device  406  moves in cassette or box  422  comprising a telescopic lifting cylinder  430 . Box  422  provides a pit with a slot or recess  424  for guiding the moveable lifting column/device  406 . Moveable lifting column/device  406  is provided with carrier  426  whereon axle carriers  428  are mounted. Depending on the type of vehicle  432  additional adapters can be provided that cooperate with carriers  414 ,  426  to enable engagement with different axle dimensions. 
     Columns/devices  404 ,  406  are provided with transponders  28   a . When storing column  406  descent system  78  controls the position of column/device  406  relative to hatches/recesses  434 . Optionally, this can be performed automatically by controller  22 . 
     In an alternative lifting system  502  of the in-ground type ( FIG.  6   ) the telescopic lifting cylinders  412 ,  430  of lifting system  402  are replaced by scissor type lifts  504 ,  506 . It will be understood that operation of lifting systems  402 ,  502  of the in-ground type is similar. 
     Lifting system  600  comprises a set of four lifting devices  102  ( FIG.  7   ). Lifting columns  602  lift passenger car  604  from ground  606 . In the illustrated embodiment lifting columns  602  are connected to each other by wireless communication means. Lifting columns  602  comprise foot  604  which can travel on running wheels  606  over ground surface  6  or for instance a floor of a garage or workshop. In the forks of foot  604  there is provided additional running wheel  608 . Running wheel  606  is part of pallet truck mechanism  610  that enables easy maneuvering of mobile lifting column  602 . Lifting column  602  further comprises mast  616  and carrier  618  that is movable up downward along mast  616 . Carrier  618  is driven by motor/drive system  620 . 
     In the illustrated embodiment each lifting column  602  is provided with the local controller  622  that allows a user to control lifting system  600 . In the illustrated embodiment separate controller  624  with optional display  626  is provided. 
     Also, in the illustrated embodiment lifting system  600  comprises remote control  628 . In the illustrated embodiment remote control  628  comprises emergency stop  638 , lifting button  640 , lowering button  642 , unlock button  644 , and confirmation bottom  646 . In addition, display  648  is provided. It will be understood that other configurations for remote control  628  can also be envisaged in accordance with the present invention. 
     In the illustrated embodiment remote control  628  comprises RFID tag  657  as part of RFID-system  650 . Controller  624  comprises RFID-reader  652  in the illustrated embodiment. It will be understood that other configurations for the RFID-system  650  can also be envisaged in accordance with the present invention. 
     Remote control  628  further optionally comprises magnetic coupling  654  to enable coupling remote control  16  to lifting device  2 . Also optionally, lamp  656  is provided to generate a torch-like functionality to remote control  628  and/or provide a visual warning means as an alternative or in addition to acoustic signaler  658  that is optionally provided in remote control  628  or control  624 . In the illustrated embodiment de-activator  660  is schematically illustrated in remote control  628 . Charger  662 , preferably of the wireless type, is schematically illustrated for lifting system  600 . 
     Transmitter/receiver(s)  664  are provided to remote control  628  and control  624  and provide an embodiment of a wireless communication coupling for lifting system  600 . Transmitter/receiver(s)  664  are configured for coupling to another lifting device to enable joint coupling of a vehicle, such as vehicle  604 , with one, two, (or) more lifting systems  600  and/or any of the other lifting devices or systems. 
     The activation distance  666  is schematically illustrated in  FIG.  7    for remote control  628  and lifting system  600 . De-activator  670  is schematically illustrated in remote control  16 . De-activator  670  deactivates remote control  628  when activation distance  666  is larger than a threshold value and/or a time-out period (time period without activity) is larger than a threshold value. 
     Furthermore, it will be understood that a controller  624  capable of controlling multiple lifting devices  602  can be provided as a separate controller and/or similar control functions can be incorporated in local controller  622  that also can be used to control the other lifting devices  602  in lifting system  600 . 
     Monitoring system  680  is schematically illustrated in  FIG.  7   . Monitoring system  680  optionally comprises monitoring controller  681  that can alternatively be integrated with any of the other controllers. In this illustrated embodiment safety zone  682  is provided that comprises inner zone  684  directly below vehicle  640 , intermediate zone  686  directly around vehicle  604 , and outer zone  688 . Preferably, in inner zone  684  remote control  628  can be operated with limited functionality, for example with limited speed, only ascent and no descent functionality. In intermediate zone  686  remote control  628  has full operational functionality. In outer zone  688  remote control  628  does not function. This functional restriction in outer zone  688  can be achieved in software taking the location of remote control  628  into account and/or by limiting the transmission power such that control actions cannot be successfully transferred by remote control  628  to lifting system  600  with lifting devices  602 . In the illustrated embodiment intermediate zone  686  lies between inner zone  684  and outer zone  688  with a width preferably in the range of 1 to 5 meters, and more preferably about 2 meters. 
     Optionally, and is schematically illustrated in  FIG.  7   , lifting system  600  and/or lifting devices  602  comprise orientation detector  690  to detect the actual position and orientation of the system/device. Also optionally, adaptation system  692  is provided in device  602  and/or remote control  628  to adapt the boundaries of one or more of zones  684 ,  686 ,  688 , optionally making use of the actual height H of vehicle  604 . Also optionally, there is provided vehicle detector  694  and/or engagement safety system  696  for monitoring engagement of carrier  610  to vehicle  604  when lifting vehicle  604  and/or descent safety system  698  for monitoring a safe descent of carrier  618  and/or release system  699  for releasing carrier  618  enabling lifting device  602  and system  600  to lift vehicle  604 . 
     Also optionally, safety surround system  697  comprises one or more cameras  697   a,b  and/or  697   c,d . In the preferred and illustrated embodiment safety surround system  697  comprises two (or more) cameras/mirrors  697   a,b,c,d  that are preferably provided at or adjacent the corners of lifting system  600  to provide an operator with a full view around vehicle  604 . Optionally, camera views are shown on display  648  of remote control  628  and or display  649  of lifting device  602 . 
     Method  1002  ( FIG.  8   ) of lifting a vehicle starts in step  1004  with the selection of remote control  16 ,  128  ( FIG.  8   ) after which authorization step  1006  is performed, wherein optionally a user is identified and/or authorized to perform certain operations with certain lifting devices. Thereafter, the lifting device or lifting devices are optionally selected in selection step  1008  using remote control  128  or any of the local controllers. Optionally, a further lifting device or system is selected in step  1010 . For example, this step can be used in different situations, including when lifting trains or road trains, or articulated/accordion buses. The control of the lifting operation is started in step  1012  whereafter the vehicle can be lifted in lifting step  1014 . After work on the vehicle is performed or otherwise ended, a deactivation step  1016  is performed to end the operation of lifting vehicle  4 . 
     Safety protocol  1050  ( FIG.  9   ) involves communication check  1052 . Check  1052  involves checking communication is received within a specific time interval. Optionally, distance check  1054  is performed to check distance  666  between remote control  628  and the one or more lifting devices. Also optionally, activity check  1056  is performed, preferably involving starting a time-out time period after an action is performed. In case the timeout period passes and/or exceeds a threshold value without any further activity from a user and/or distance  666  exceeds a threshold value, the remote control  628  is decoupled from the respective lifting device. 
     It will be understood that the invention can be applied to a range of lifting systems, including but not limited to four-post and two-post lifting columns, such as the Stertil-Koni one post lifts ST 1075 , the Stertil-Koni two post lifts SK  2070 , and the Stertil-Koni four post lifts ST  4120 , skylift, mobile columns, and in-ground lifts, such as the Stertil in-ground Ecolift and the Stertil in-ground Diamond lift. Also, it will be understood that additional embodiments of the invention can be envisaged combining and/or switching features from the described and/or illustrated embodiments. For example, instead of light  110 ,  210 , or in addition thereto, sound signals, indications on a control system etc. can be applied. 
     When vehicle  6 ,  432 ,  604  needs to be lifted, lifting system  2 ,  102 ,  202 ,  302 ,  402 ,  502 ,  600  is activated. For example, a user can activate the lifting system with remote control  48 . Preferably, a safety zone  60 ,  74 ,  682  is provided to increase the overall safety. The size of these zones can be adjusted depending on vehicle type and/or carrier height. Carrier height is determined using indoor positioning system  28  in combination with transponders  28   a , electronic compass  28   b  and “satellites”  28   c . In case of mobile lifting columns  4 , the selection of specific lifting column  4  to be included in a group  2   a ,  2   b  can be done by central controller  22  using information of the specific location and carrier height of available lifting columns  4 , for example. Such selection can be presented to the user as a suggestion that requires authorization by the user or can be selected automatically by controller  22 . Release system  22  may lock/unlock carrier  16  as an additional safety measure. In case someone or something enters specific parts of safety zone  60 ,  74 , central controller  22  is informed and may instruct release system  72  to lock carrier  16 . Carrier  16  can be unlocked after the person or object is removed from safety zone  60 ,  74 ,  682  for example. This can be performed automatically or requires user authorization or user input. Positions of persons and/or objects including tools and accessories can be controlled by providing additional transponders  50  in these tools and/or objects. This further enables monitoring and control of the engagement of carrier  16  to vehicle  6 ,  432 ,  604  when involving these tools, such as an axle stand, transmission jack or wheel dolly, for example. 
     The present invention is by no means limited to the above described preferred embodiments. The rights sought are defined by the following claims within the scope of which many modifications can be envisaged. The present invention is described using a lifting device such as a lifting column and more specifically a mobile lifting column. The invention can also be applied to other type of lifting columns such as so-called boom-lifts, scissor-lifts and loading platforms. Such lifting equipment can be provided with the measures illustrated above according to the invention.