1. A charge control system for charging, from an external AC power supply, a vehicle control system for a motor-driven lawnmower vehicle, wherein:
the vehicle control system comprises a plurality of electric motors, a plurality of controllers, a battery, a charging port, and a charger recognition unit;
among the plurality of electric motors, at least one electric motor is an electric drive motor connected to a drive wheel of the motor-driven lawnmower vehicle in a manner capable of transmitting motive power, and among others of the plurality of electric motors, at least one electric motor is a mower-related electric motor connected to a lawnmower rotary tool in a manner capable of transmitting motive power;
the plurality of controllers include a drive wheel controller, a mower-related controller, and a main controller;
the drive wheel controller is structured to control operation of the electric drive motor;
the mower-related controller is structured to control the mower-related electric motor;
the battery supplies electric power to the electric drive motor and the mower-related electric motor;
the charging port includes a first port connected to the battery and a second port, the charging port being provided in the motor-driven lawnmower vehicle;
when a first connector of a charging cable connected to the external AC power supply is connected to the first port, the second port is connected with a second connector of the charging cable;
the charger recognition unit is connected to the second port and transmits a charger recognition signal to the main controller when the second connector is connected to the second port; and
upon receipt of the charger recognition signal, the main controller is structured to control the drive wheel controller and the mower-related controller so as to prohibit operation of the electric drive motor and the mower-related electric motor.
2. The charge control system according to claim 1, wherein
the main controller is connected to the drive wheel controller and the mower-related controller, and transmits a first control signal to the drive wheel controller in response to the sensor signal from the at least one operator sensor, and further transmits a second control signal to the mower-related controller in response to a switch-related signal from a mower starting switch.
3-19. (canceled)
20. The charge control system according to claim 1, wherein
during charging of the battery from the external AC power supply, when at least one of the operator and the mower starting switch is operated, the main controller causes an indicator to display predetermined characters or causes an alarming unit to generate an alarm sound.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of using a computer to represent an inverted list record containing a key and one or more ordered logical or physical pointers, the number of said pointers being n, by logically subdividing said inverted list into m ordered groups of pointers, m being smaller than or equal to n, each group containing a number of pointers larger than or equal to 1, and representing each group by a group record consisting of the key of said inverted list record followed by a representation of said group of pointers, different group records being able to have different representations, each group record being stored in an index structure organized by pages, wherein a representation contains
a. an interval specification containing the lowest pointer value in the group, and an optional range specification, said range specification consisting of the highest pointer value in the group or, in alternative, of the difference between the highest pointer in the group and the lowest pointer in the group, the lowest pointer and the range specification being compressed or uncompressed, and
b. an optional data part containing all the pointers in the group, with the exception of the lowest pointer, and of the highest pointer if a range specification exists.
2. A method of using a computer to compress records in a page by a prefix compression wherein:
each record being composed by a key followed by data content;
records in a page being ordered by key values;
said prefix compression being obtained by identifying a common prefix between the current record to be compressed and the previous record in the page;
said common prefix denoting the number of bytes that are equal in both records, starting with the first byte of each record;
said common prefix being empty if the record to be compressed is the first record in the page;
said prefix compression compressing a record by not explicitly storing the common prefix but representing it by its length in terms of bytes, and
where locating the first record whose key matches a given search key is performed by
a. initially setting a variable P with the first record in the page, comparing the search key with the key in said first record, if the two keys are equal P is returned, whereas if they are not equal, raising a record-not-found condition if the search key is smaller than the key in P, otherwise if the search key is larger than the key in P setting a variable D with the index in the search key, starting at 1, of the first byte that is different between the two keys;
b. perform a forward scan ignoring without decompressing all records with a common prefix equal to or larger than D, stopping said scan with a record-not-found condition when an end-of-scan condition occurs or if the current record has a common prefix smaller than D\u22121,
c. if the current record has a common prefix equal to D\u22121, decompressing said record using P as the previous record, setting P with said decompressed record and comparing said search key with the key of the current record, returning P if they are equal, otherwise setting D to the index of the first byte that is different between the two keys and iterating steps b and c.
3. The method of claim 1 where inverted list records on a page are managed by the method in claim 2.
4. The method of claim 1 in which the data part of the representation of a group of N pointers in a group record is a bitmap of length N\u2032, where N\u2032=N\u22122 if the range specification is present or N\u2032=N\u22121 otherwise, the i-th bit of said bitmap, where i is larger than or equal to 1 and i is lower than or equal to N\u2032, being set if there exists a pointer in said group of pointers such that its value is equal to the lowest pointer value in the group incremented by i, said representation being called a bitmapped representation.
5. The method of claim 1 in which the data part of the representation of a group of N pointers in a group record is a compressed representation of the group of pointers from which the lowest pointer value is excluded, the highest pointer value being excluded if a range specification is present, said representation being called a compressed representation.
6. The method of claim 1 in which the representation of a group of N pointers in a group record where said pointers are contiguous or N is equal to 1, has a mandatory range specification and has no additional data part, said representation being called a contiguous representation;
7. The method of claim 1 in which the representation of a group of N pointers in a group record where N is equal to 1, only contains the single pointer in the group, with no range specification and no data part, said representation being called a point representation.
8. The method of claim 1 further comprising the sequential read of the pointers in an inverted list through a cursor C with a component C.pos identifying the current record in the ordered list of records, and a component C.cont representing a group of pointers in the form <ps, pe>, where C.cont.ps identifies the lowest pointer and C.cont.pe the highest pointer in the group, C.cont being set when the current record identified by C.pos is read and being derived from the interval specification of the current record by setting C.cont.ps to the lowest pointer in the group and C.cont.pe being set to the highest pointer in the group, said highest pointer being either exactly computed from the existing range specification in the group record or estimated, and further characterized by an operation of advancing the cursor to the next pointer wherein:
if the current pointer C.cont.ps is not the last pointer in the current record, C.cont.ps is set to the next pointer in the current record, and C.cont.ps is returned; otherwise
if the current pointer C.cont.ps is the last pointer in the current record, the next record in the inverted list is read, if said record does not exist an end-of-scan condition being returned, otherwise C.cont.ps being returned.
9. The method of claim 8 further characterized by estimating the highest pointer in the group as the lowest pointer in the next record with the same key, said lowest pointer decreased by 1, if such next record exists, or the largest possible pointer value otherwise.
10. The method of claim 8 further characterized by an operation that advances said cursor C to a value x wherein:
while x>C.cont.pe, the cursor is advanced to the next record,
if x\u2266C.cont.ps, the cursor is not advanced,
if C.cont.ps<x\u2266C.cont.pe, the cursor is advanced to the next pointer until x\u2266C.cont.ps.
11. The method of claim 10 further comprising computing the intersection of N inverted lists, said intersection consisting of only those pointers that appear in all the lists, each list J having a cursor CJ, by the following steps:
a. compute minp as the minimum value of CJ.cont.pe for all the cursors and maxp as the maximum value of CJ.cont.ps for all the cursors;
b. if minp\u2267maxp then compute the intersection among the lists in the interval <maxp, minp> and advance each cursor to minp+1, otherwise advance each cursor to maxp, iterate in both cases steps a and b until any cursor returns an end-of-scan condition during advancing;
wherein:
if all cursors are defined on a contiguous or point representation, the output of the intersection in the interval <maxp, minp> is given by all the values in said interval;
otherwise, the output of the intersection in the interval <maxp, minp> is computed by ignoring all the cursors defined on a contiguous representation, and outputting all the values in the interval <maxp, minp> that appear in all the remaining cursors.