Patents by Inventor Kandasamy Thangavelu
Kandasamy Thangavelu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5841084Abstract: A group controller for controlling elevator cars in a building having a plurality of floors includes a traffic and traffic rate estimator for providing fuzzy estimates of traffic and traffic rate; an open loop fuzzy logic controller for providing a control parameter in response to the fuzzy estimates of traffic and traffic rate, the open loop fuzzy logic controller having membership functions for fuzzy sets of the control parameter; an adaptive controller for modifying the membership functions of the fuzzy sets of the control parameter in response to an elevator control system output variable; and an elevator dispatcher for controlling the operation of the elevator cars during single source traffic conditions in response to the control parameter.Type: GrantFiled: November 30, 1995Date of Patent: November 24, 1998Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5808247Abstract: A system for controlling elevator cars in a building having a plurality of floors includes a group controller for controlling operation of the elevator cars. The group controller predicts lobby single source traffic for determined periods. When the predicted traffic is below certain limit, cars are assigned to a lobby hall call on demand after hall call registration. When the predicted traffic is above certain limit, cars are assigned to the lobby hall call at intervals. Accordingly, car assignment is scheduled at those intervals. The schedule interval is varied based on predicted traffic and predicted round trip time of the cars. The cars are assigned to hall calls if they arrive within a schedule window. The schedule window comprises a lower and an upper tolerance that are selected around a scheduled time.Type: GrantFiled: November 30, 1995Date of Patent: September 15, 1998Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5786551Abstract: A group controller for controlling elevator cars in a building having a plurality of floors includes a traffic and traffic rate estimator for providing fuzzy estimates of traffic and traffic rate; a closed loop fuzzy logic controller for providing a control parameter in response to the fuzzy estimates of traffic and traffic rate and in response to an elevator control system output variable; and an elevator dispatcher for controlling the operation of the elevator cars during single source traffic conditions in response to the control parameter.Type: GrantFiled: November 30, 1995Date of Patent: July 28, 1998Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5786550Abstract: A elevator system including a group controller for controlling the dispatching of elevator cars to the lobby. The group controller predicts lobby single source traffic for short periods. When the predicted traffic is below certain limit, cars are assigned to a lobby hall call on demand after hall call registration. When the predicted traffic is above certain limit, cars are assigned to the lobby hall call at intervals. Accordingly, car assignment is scheduled at those intervals. The traffic threshold at which the scheduled mode is activated and the traffic threshold at which it is deactivated is learned by the system. The schedule interval is varied based on predicted traffic and predicted round trip time of the cars. The number of cars assigned and sent to the lobby is varied based on predicted traffic. In order to avoid oscillations in selecting the service mode, proper delays are used to activate and deactivate the scheduled service.Type: GrantFiled: November 30, 1995Date of Patent: July 28, 1998Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5767462Abstract: A group controller for controlling elevator cars in a building having a plurality of floors includes a traffic and traffic rate estimator for providing fuzzy estimates of traffic and traffic rate; an open loop fuzzy logic controller for providing a control parameter in response to the fuzzy estimates of traffic and traffic rate; and an elevator dispatcher for controlling the operation of the elevator cars during single source traffic conditions in response to the control parameter.Type: GrantFiled: November 30, 1995Date of Patent: June 16, 1998Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5767460Abstract: A group controller for controlling elevator cars in a building having a plurality of floors includes an elevator dispatcher for controlling the operation of the elevator cars during single source traffic conditions, the elevator dispatcher having a constraint for limiting car assignments in response to the constraint; and an adaptive contraint generator for modifying a value of the constraint in response to an elevator control system output variable.Type: GrantFiled: November 30, 1995Date of Patent: June 16, 1998Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5750946Abstract: A system including a group controller for controlling the dispatching of elevator cars in a building. The group controller operates by using control parameters stored in its memory. The system records car loads of cars leaving the lobby and the time intervals between their departures and uses fuzzy logic to categorize the car loads and intervals into fuzzy sets. The system determines the lobby traffic and traffic rate using fuzzy relations among car loads, departure intervals, lobby traffic and traffic rate and the fuzzy logic rules. The group controller collects traffic data during operation. The system runs simulations off-line, after single source traffic periods, using the specified control parameter values. The system collects and analyzes performance data to identify significant deviations from acceptable performances. New sets of control parameters are selected using appropriate specified rules.Type: GrantFiled: November 30, 1995Date of Patent: May 12, 1998Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5714725Abstract: A group controller for controlling elevator cars in a building having a plurality of floors includes a traffic and traffic rate estimator for providing fuzzy estimates of traffic and traffic rate; a closed loop fuzzy logic controller for providing a control parameter in response to the fuzzy estimates of traffic and traffic rate and in response to an elevator control system output variable, the closed loop fuzzy logic controller having membership functions for fuzzy sets of the control parameter; an adaptive controller for modifying the membership functions of the fuzzy sets of the control parameter in response to the elevator control system output variable; and an elevator dispatcher for controlling the operation of the elevator cars during single source traffic conditions in response to the control parameter.Type: GrantFiled: November 30, 1995Date of Patent: February 3, 1998Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5411118Abstract: The present invention is directed to determining an arrival time for each of the passengers boarding an elevator car. Where the elevator car stops at a floor in response to a hall call request, the arrival time of the passengers which boarded the elevator car is preferably determined based the time period between when the hall call was registered and when the elevator car door closed. Where the elevator car stops at a floor in response to a car call registered within the elevator, the arrival time of the passengers which boarded the elevator car is preferably determined based on the time period between when the elevator stopped at the floor and when the elevator car door closed. Alternatively, the time period between when the elevator car door opened and when the elevator car door closed can be used. In the preferred embodiment, the first passenger is assumed to have an arrival time corresponding to the beginning of the time period.Type: GrantFiled: March 30, 1993Date of Patent: May 2, 1995Assignee: Otis Elevator CompanyInventors: Kandasamy Thangavelu, Venkataramana S. Pullela
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Patent number: 5241142Abstract: The present invention is directed to an elevator dispatching system for controlling the assignment of elevator cars. More particularly, the present invention is directed to a method of determining the commencement and/or conclusion of UP-PEAK and DOWN-PEAK periods of operation. For example, for commencing UP-PEAK operation, a lobby boarding rate is predicted, based on historical information of the number of passengers boarding the elevators at the lobby and the number elevators leaving the lobby. The predicted lobby boarding rate is compared with a predetermined threshold value. If the predicted lobby boarding rate is greater than the predetermined threshold value, UP-PEAK is commenced. In the preferred embodiment, the predetermined threshold value is a predetermined percentage of the elevator car's capacity. Additionally, the present invention is directed to a method of adjusting the threshold value based on actual passenger traffic.Type: GrantFiled: January 22, 1991Date of Patent: August 31, 1993Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5183981Abstract: The present invention is directed to the grouping of contiguous floors in a building into sectors. According to the present invention, historical information regarding the number of passengers arriving at each floor is obtained and used to predict the number of passengers to be arriving at each of the floors. By summing the predicted traffic per floor and dividing by the number of sectors to be formed, average traffic per sector can be determined. In the preferred embodiment, sectors are formed, starting from the first floor above the lobby and continuing through to the top floor in the building, by selecting a set of contiguous floors for each sector such that the predicted traffic for each sector is less than a predetermined threshold. Specifically, if the predicted traffic for a selectable next contiguous floor, added to the predicted traffic for all contiguous floors already selected for the sector, is less than the predetermined threshold, the selectable floor is included in the sector.Type: GrantFiled: March 2, 1990Date of Patent: February 2, 1993Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5168136Abstract: A computer controlled elevator system (FIG. 1 ) using prediction methodology to enhance the system's elevator service, having "learning" capabilities to adapt the system to changing building operational characteristics, including signal processing means for computing the "best" prediction model to be used for prediction, the best factoring coefficients for combining real time and historic predictors associated with the best prediction model, the best data and prediction time interval lengths to be used, and the optimal number of look-ahead intervals or steps (for real time predictions) or look-back days (for historic predictions) to the extent applicable to the prediction model, etc. Using the algorithm(s) of the invention the best prediction methodology and associated parameters are selected by running on site simulations based on exemplary values and comparing the prediction results to recorded data indicative of the actual events that have occurred in the system over a past appropriate period of time.Type: GrantFiled: October 15, 1991Date of Patent: December 1, 1992Assignee: Otis Elevator CompanyInventors: Kandasamy Thangavelu, V. Sarma Pullela
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Patent number: 5035302Abstract: The present invention is directed to an elevator dispatching system for controlling the assignment of elevator cars. More particularly, the present invention is directed to a method of determining the commencement and/or conclusion of UP-PEAK and DOWN-PEAK periods of operation. For example, for commencing UP-PEAK operation, a lobby boarding count is predicted, based on historical information of the number of passengers boarding the elevators at the lobby. The predicted lobby boarding count is compared with a predetermined threshold value. If the predicted lobby boarding count is greater than the predetermined threshold value, UP-PEAK is commenced. In the preferred embodiment, the predetermined threshold value is a predetermined percentage of the building's population. Additionally, the present invention is directed to a method of adjusting the threshold value based on actual passenger traffic.Type: GrantFiled: March 2, 1990Date of Patent: July 30, 1991Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 5024295Abstract: An elevator system employing a micro-processor-based group controller (FIG. 2) communicating with the cars (3, 4) to assign cars to hall calls based on a Relative System Response (RSR) approach. However, rather than using unvarying bonuses and penalties, the assigned bonuses and penalties are varied using "artificial intellience" techniques based on combined historic and real time traffic predictions to predict the number of people behind a hall call, and, calculating and using the average boarding and de-boarding rates at "en route" stops, and the expected car load at the hall call floor. Prediction of the number of people waiting behind hall calls for a few minute intervals are made using traffic levels measured during the past few time intervals on that day as real time predictors, using a linear exponential smoothing model, and traffic levels measured during similar time intervals on previous similar days as historic traffic predictors, using a single exponential smoothing model.Type: GrantFiled: March 3, 1989Date of Patent: June 18, 1991Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 4846311Abstract: An elevator system containing a group of elevator cars (1-4) and a group controller (32) having signal processing means (CPU) for controlling the dispatching of the cars from a main floor or lobby (L) in relation to different group parameters. During up-peak conditions, each car is dispatched from the main floor to an individual plurality of contiguous floors, defining a "sector" (SN). Sectors are contiguous, and the number of sectors may be less than the number of cars, and a floor can be assigned to more than one sector. Floors that constitute a sector assigned exclusively to a car are displayed on an indicator (SI) at the lobby. Cars are selected for assignment by grouping floors into sectors and appropriately selecting sectors, so that each elevator car handles more or less an equal predicted traffic volume during varying traffic conditions, resulting in the queue length and waiting time at the lobby being decreased, and the handling capacity of the elevator system increased.Type: GrantFiled: June 21, 1988Date of Patent: July 11, 1989Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 4838384Abstract: Elevator system with multiple cars (1-4) and a group controller (32) having signal processing means (CPU) controlling car dispatching from the lobby (L). During peak conditions (up-peak, down-peak and noontime), each car is dispatched and assigned to hall call floors having a large predicted number of passengers waiting on priority basis, resulting in queue length and waiting time at the lobby and upper floors being decreased, and system handling capacity increased. Estimations of future traffic flow levels for the floors for five minute intervals are made using traffic levels measured during the past few time intervals on that day as real time predictors, using a linear exponential smoothing model, and traffic levels measured during similar time intervals on previous similar days as historic traffic predictors, using a single exponential smoothing model.Type: GrantFiled: June 21, 1988Date of Patent: June 13, 1989Assignee: Otis Elevator CompanyInventor: Kandasamy Thangavelu
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Patent number: 4804069Abstract: An elevator system contains a group of elevator cars. A group controller contains signal processing means for controlling the dispatching of the cars from a main floor or lobby in relation to different group parameters. During up-peak conditions, each car is dispatched from the main floor to an individual plurality of contiguous floors, defining a "sector". Sectors are contiguous. The number of sectors may be less than the number of cars. Floors that constitute a sector assigned exclusively to a car are displayed on an indicator at the lobby. Sectors and cars are selected for assignment in a cyclical or round-robin sequence. If the next car selected is not available for assignment, another car is selected. If no car calls are made to the floors in the sector that is assigned to a car, the next sector is selected. The floors in the sector assigned to a car are displaced to direct passengers to the car.Type: GrantFiled: February 12, 1988Date of Patent: February 14, 1989Assignee: Otis Elevator CompanyInventors: Joseph Bittar, Kandasamy Thangavelu
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Patent number: 4792019Abstract: An elevator system contains a group of elevator cars. A group controller contains signal processing means for controlling the dispatching of the cars from a main floor or lobby in relation to differnt group parameters. During up-peak conditions, each car is dispatched from the main floor to an individual plurality of contiguous floors, defining a "sector". Sectors are contiguous. The number of sectors may be less than the number of cars. Floors that constitute a sector are assigned exclusively to a car and are displayed on an indicator at the lobby. Sectors are selected for assignment according to preset order (e.g. numerical). Cars are selected for assignment to a selected sector according to a preset order (e.g. numerical). If no car calls are made to the floors in the sector that is assigned to a car, the next sector is selected along with the next car according to that order.Type: GrantFiled: February 12, 1988Date of Patent: December 20, 1988Assignee: Otis Elevator CompanyInventors: Joseph Bittar, Kandasamy Thangavelu