摘要:
An articulated machine and method of operation, the articulated machine having a first frame with a first traction device and a steering apparatus that controls a steering angle thereof, the first frame pivotally coupled to a second frame at an articulation joint, the second frame having a second traction device, a steering sensor configured to provide a steering signal indicative of the steering angle, and an electronic controller configured to automatically control an articulation angle based on the steering signal.
摘要:
An articulated machine and method of operation, the articulated machine having a first frame with a first traction device and a steering apparatus that controls a steering angle thereof, the first frame pivotally coupled to a second frame at an articulation joint, the second frame having a second traction device, a steering sensor configured to provide a steering signal indicative of the steering angle, and an electronic controller configured to automatically control an articulation angle based on the steering signal.
摘要:
A system is provided for positioning a work implement. The system has at least one actuator for actuating a movement of a work implement. The system also has at least one sensor associated with the at least one actuator and configured to sense at least one parameter indicative of a position and an orientation of the work implement. Furtherrnore, the system has a controller configured to automatically create a travel path for the work implement and guide the work implement in response to the data received from the at least one sensor, wherein the controller is further configured to automatically modify the travel path when detecting an imminent collision between the work implement and an obstacle.
摘要:
A database table is provided. The database table includes several column tuples. A column is selected in the database table. The column tuples of the selected column are partitioned into several bins. Each bin includes a range of tuples and associated metadata. The associated metadata includes at least one of: a minimum tuple value for the tuples in the bin, a maximum tuple value for the tuples in the bin, a minimum tuple identifier for the bin and a maximum tuple identifier for the bin. The bins are sorted based on the tuple values to provide an approximate index for the database.
摘要:
A method for estimating contents of a cache determines table descriptors referenced by a query, and scans each page header stored in the cache for the table descriptor. If the table descriptor matches any of the referenced table descriptors, a page count value corresponding to the matching referenced table descriptor is increased. Alternatively, a housekeeper thread periodically performs the scan and stores the page count values in a central lookup table accessible by threads during a query run. Alternatively, each thread independently maintains a hash table with page count entries corresponding to table descriptors for each table in the database system. A thread increases or decreases the page count value when copying or removing pages from the cache. A page count value for each referenced table descriptor is determined from a sum of the values in the hash tables. A master thread performs bookkeeping and prevents hash table overflows.
摘要:
A database table is provided. The database table includes several column tuples. A column is selected in the database table. The column tuples of the selected column are partitioned into several bins. Each bin includes a range of tuples and associated metadata. The associated metadata includes at least one of: a minimum tuple value for the tuples in the bin, a maximum tuple value for the tuples in the bin, a minimum tuple identifier for the bin and a maximum tuple identifier for the bin. The bins are sorted based on the tuple values to provide an approximate index for the database.
摘要:
A system is provided for regulating a travel course of a machine. The system has a steering system operationally connected to at least one ground engaging device. Additionally, the system has a path generator configured to generate a path along which the machine can travel. The system also has a path tracker configured to automatically regulate the steering system to position the machine within a predetermined vicinity of an initial point on the generated path and guide the machine along the generated path.
摘要:
A system is provided for regulating a travel course of a machine. The system has a steering system operationally connected to at least one ground engaging device. Additionally, the system has a path generator configured to generate a path along which the machine can travel. The system also has a path tracker configured to automatically regulate the steering system to position the machine within a predetermined vicinity of an initial point on the generated path and guide the machine along the generated path.
摘要:
A method for estimating contents of a cache determines table descriptors referenced by a query, and scans each page header stored in the cache for the table descriptor. If the table descriptor matches any of the referenced table descriptors, a page count value corresponding to the matching referenced table descriptor is increased. Alternatively, a housekeeper thread periodically performs the scan and stores the page count values in a central lookup table accessible by threads during a query run. Alternatively, each thread independently maintains a hash table with page count entries corresponding to table descriptors for each table in the database system. A thread increases or decreases the page count value when copying or removing pages from the cache. A page count value for each referenced table descriptor is determined from a sum of the values in the hash tables. A master thread performs bookkeeping and prevents hash table overflows.
摘要:
A system is provided for regulating a travel course of a machine. The system has a steering system operationally connected to at least one ground engaging device. Additionally, the system has a path generator configured to generate a path along which the machine can travel. The system also has a path tracker configured to automatically regulate the steering system to position the machine within a predetermined vicinity of an initial point on the generated path and guide the machine along the generated path.