Materials handling and other vehicles with functional responses to runtime calculation
Battery management systems, removable battery assemblies with integrated battery management systems, and vehicles are provided for implementing the various runtime calculations disclosed herein. A vehicle, which may be a materials handling vehicle, is provided comprising a drive subsystem, a removable battery assembly, and vehicle control hardware. The battery assembly comprises a battery management system programmed to input or generate a state of charge signal representing a state of charge SOC of the battery assembly, implement a first EWMA signal filter F 1 to calculate a succession of contemporary current calculations I C , implement a second EWMA signal filter F 2 to calculate a runtime current I R , wherein the runtime current calculation I R comprises the contemporary current calculations I C from the first EWMA signal filter F 1 , and implement a remaining runtime calculation such that the vehicle control hardware responds functionally to the runtime calculation.
1. A materials handling vehicle comprising a materials handling subsystem, a drive subsystem, a removable battery assembly, and vehicle control hardware, wherein:
the vehicle control hardware is either dedicated to the materials handling subsystem, the drive subsystem, or the removable battery assembly, or shared by a combination thereof;
the materials handling subsystem, the drive subsystem, and the vehicle control hardware are powered by the removable battery assembly;
the removable battery assembly comprises a battery management system that is programmed to
input or generate a state of charge signal representing a state of charge (SOC) of the battery assembly,
implement a first Exponentially Weighted Moving Average (EWMA) signal filter F 1 to calculate a succession ( 0 I C , 1 I C , 2 I C , . . . ) of contemporary current calculations I C wherein the contemporary current calculations advance by a time interval t 1 and comprise
I C =[( A×β 1 )]+[ B ×(1−β 1 )]
and where A comprises an average current load on the battery over the time interval t 1 , B comprises a predetermined current load or a historic EWMA current calculation that precedes the average current load of A, temporally, and β 1 comprises a first weighting parameter,
implement a second EWMA signal filter F 2 to calculate a runtime current I R , wherein the runtime current calculation comprises
I R =[( C×β 2 )]+[ D ×(1−β 2 )]
and where C comprises an average, over a time envelope t E , of a plurality of the succession ( 0 I C , 1 I C , 2 I C , . . . ) of contemporary current calculations I C from the first EWMA signal filter F 1 , D comprises a historic EWMA current calculation that precedes temporally at least one of the plurality of the succession ( 0 I C , 1 I C , 2 I C , . . . ) of contemporary current calculations I C from the first EWMA signal filter F 1 , and β 2 comprises a second weighting parameter, and
implement a remaining runtime calculation R comprising
R=SOC/I R ; and
the vehicle control hardware is programmed to respond functionally to the runtime calculation R.
2. The materials handling vehicle of claim 1 wherein:
the battery management system is programmed to output a control signal based on the runtime calculation R; and
the vehicle control hardware is programmed to respond functionally to the control signal.
3. The materials handling vehicle of claim 1 wherein:
the vehicle control hardware of the materials handling subsystem comprises user-interfacing lift/lower controls and supporting electronics and the user-interfacing lift/lower controls and supporting electronics are configured to automatically cut off, progressively limit, or otherwise disable, lift/lower functionality of the materials handling vehicle, as a function of the runtime calculation R, or when the runtime calculation R falls below a predetermined threshold; or
the vehicle control hardware of the materials handling subsystem comprises user-interfacing drive mode controls and supporting electronics and the user-interfacing drive mode controls and supporting electronics are configured to automatically cut off, progressively limit, or otherwise disable, specific drive modes of the materials handling vehicle, as a function of the runtime calculation R, or when the runtime calculation R falls below a predetermined threshold.
4. The materials handling vehicle of claim 1 wherein:
the vehicle control hardware of the materials handling subsystem comprises battery hardware and supporting electronics; and
the battery hardware and supporting electronics comprise battery insertion/removal hardware, diagnostic controls, or visual displays on the battery assembly, and are configured to automatically change, enable, or disable, as a function of the runtime calculation R, or when the runtime calculation R falls below a predetermined threshold.
5. The materials handling vehicle of claim 4 wherein the battery hardware and supporting electronics comprises a visual runtime display on the battery, or elsewhere on the vehicle, that is configured to progressively change as a function of the runtime calculation R.
6. The materials handling vehicle of claim 1 wherein the battery management system is programmed to reduce the time envelope t E of the second EWMA signal filter F 2 when the SOC of the battery assembly falls below a first SOC threshold.
7. The materials handling vehicle of claim 6 wherein the battery management system is programmed to further reduce the time envelope t E of the second EWMA signal filter F 2 when the SOC of the battery assembly falls below a second SOC threshold that is lower than the first SOC threshold.
8. The materials handling vehicle of claim 7 wherein the first SOC threshold is between approximately 10% and approximately 30% and the second SOC threshold is between approximately 5% and approximately 20%.
9. The materials handling vehicle of claim 1 wherein:
β 2 <β 1 .
10. The materials handling vehicle of claim 1 wherein:
1.5/β 2 <β 1 .
11. The materials handling vehicle of claim 1 wherein the battery management system is programmed to implement the first EWMA signal filter F 1 with B comprising a historic EWMA current calculation that is taken before the materials handling vehicle enters an atypical mode of operation.
12. The materials handling vehicle of claim 1 wherein:
the battery management system is programmed to implement the first EWMA signal filter F 1 with B comprising a predetermined current load when a historic EWMA current calculation is not available, and
B >(0.5) I MAX
where I MAX comprises a maximum current load on the battery assembly with the materials handling subsystem, the drive subsystem, and the vehicle control hardware configured to cooperate to execute the plurality of pick/place operations.
13. The materials handling vehicle of claim 1 wherein the battery management system is programmed to implement the first EWMA signal filter F 1 with B comprising a historic EWMA current calculation that is an average of the average current load A and one or more previously calculated EWMAs of battery assembly current load.
14. The materials handling vehicle of claim 1 wherein the battery management system is programmed to calculate successive runtime currents IR 1 , IR 2 , IR 3 , etc., by temporally advancing sampling periods associated with the average C and the historic EWMA current calculation D of the second EWMA signal filter F 2 .
15. The materials handling vehicle of claim 14 wherein the sampling periods associated with the average C and the historic EWMA current calculation D of the second EWMA signal filter F 2 are both advanced by the time interval t 1 to calculate the successive runtime currents IR 1 , IR 2 , IR 3 , etc.
16. The materials handling vehicle of claim 1 wherein:
the battery management system is programmed to implement the first EWMA signal filter F 1 with B comprising a historic EWMA current calculation that is an average of the average current load A and one or more previously calculated EWMAs of battery assembly current load;
the battery management system is programmed to calculate successive runtime currents IR 1 , IR 2 , IR 3 , etc., by temporally advancing sampling periods associated with the average C and the historic EWMA current calculation D of the second EWMA signal filter F 2 ; and
the sampling periods associated with the average C and the historic EWMA current calculation D of the second EWMA signal filter F 2 are both advanced by the time interval t 1 to calculate the successive runtime currents IR 1 , IR 2 , IR 3 , etc.
17. The materials handling vehicle of claim 1 wherein the materials handling subsystem, the drive subsystem, and the vehicle control hardware are configured to cooperate to execute the plurality of pick/place operations such that an actual current load I on the battery assembly cycles between a local maximum and a local minimum a plurality of times over the time interval t 1 .
18. The materials handling vehicle of claim 17 wherein the local maximum and the local minimum differ by at least approximately 1000 mA and the time interval t 1 is approximately 1 min.
19. The materials handling vehicle of claim 17 wherein the time interval t 1 is ≤1 min and the local maximum and the local minimum are both greater than 0 mA and differ by at least approximately 1000 mA.
20. The materials handling vehicle of claim 19 wherein the local maximum is greater than zero Ampere and the local minimum is less than or equal to 0 mA.
21. The materials handling vehicle of claim 20 wherein the local maximum and the local minimum differ by at least approximately 1000 mA and less than approximately 5000 mA.
22. The materials handling vehicle of claim 1 wherein
the materials handling subsystem, the drive subsystem, and the vehicle control hardware are configured to cooperate to execute the plurality of pick/place operations such that an actual current load I on the battery assembly cycles a plurality of times over the time interval t 1 between local maxima and local minima that differ by at least approximately 1000 mA and less than approximately 5000 mA;
the battery management system is programmed to implement the first EWMA signal filter F 1 with B comprising a historic EWMA current calculation that is an average of the average current load A and one or more previously calculated EWMAs of battery assembly current load;
the battery management system is programmed to calculate successive runtime currents IR 1 , IR 2 , IR 3 , etc., by temporally advancing sampling periods associated with the average C and the historic EWMA current calculation D of the second EWMA signal filter F 2 ;
the sampling periods associated with the average C and the historic EWMA current calculation D of the second EWMA signal filter F 2 are both advanced by the time interval t 1 to calculate the successive runtime currents IR 1 , IR 2 , IR 3 , etc; and
1.5/β 2 <β 1 .
23. A vehicle comprising a drive subsystem, a removable battery assembly, and vehicle control hardware, wherein:
the vehicle control hardware is either dedicated to the drive subsystem, or the removable battery assembly, or shared by a combination thereof;
the drive subsystem, and the vehicle control hardware are powered by the removable battery assembly;
the removable battery assembly comprises a battery management system that is programmed to
input or generate a state of charge signal representing a state of charge (SOC) of the battery assembly,
implement a first Exponentially Weighted Moving Average (EWMA) signal filter F 1 to calculate a succession ( 0 I C , 1 I C , 2 I C , . . . ) of contemporary current calculations I C ,
implement a second EWMA signal filter F 2 to calculate a runtime current I R , wherein the runtime current calculation I R comprises the contemporary current calculations I C from the first EWMA signal filter F 1 , and
implement a remaining runtime calculation R comprising
R=SOC/I R ; and
the vehicle control hardware is programmed to respond functionally to the runtime calculation R.