US 12,325,976 B2
Control device and control method for controlling output of drive source of work vehicle
Kenichi Yamada, Tokyo (JP); and Shogo Miyazaki, Tokyo (JP)
Assigned to KOMATSU LTD., Tokyo (JP)
Appl. No. 17/283,039
Filed by KOMATSU LTD., Tokyo (JP)
PCT Filed Nov. 12, 2019, PCT No. PCT/JP2019/044354
§ 371(c)(1), (2) Date Apr. 6, 2021,
PCT Pub. No. WO2020/105512, PCT Pub. Date May 28, 2020.
Claims priority of application No. 2018-216735 (JP), filed on Nov. 19, 2018.
Prior Publication US 2021/0348363 A1, Nov. 11, 2021
Int. Cl. E02F 9/20 (2006.01)
CPC E02F 9/2066 (2013.01) [E02F 9/2029 (2013.01); E02F 9/2033 (2013.01); E02F 9/2079 (2013.01); E02F 9/2083 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A control device for a work vehicle that includes
a drive source,
a traveling device that is driven by a drive force of the drive source,
a transmission having an input shaft and an output shaft, the input shaft being connected to the drive source and the output shaft being connected to the traveling device, the transmission transmitting the drive force from the input shaft to the output shaft,
an operation device configured to be operated to set a magnitude of the drive force in accordance with an operation amount of the operation device, and
a work equipment used to excavate a work target object,
the control device comprising a processor, the processor being configured to
determine a required output torque of the transmission based on the operation amount of the operation device and a traveling speed of the work vehicle,
estimate a traveling load torque acting on the work vehicle based on a torque of the drive source, a rotation speed ratio between the input shaft and the output shaft of the transmission, and a rotation speed of the output shaft,
specify a work state of the work vehicle,
determine an allowable acceleration of the work vehicle based on the work state,
calculate an upper limit value and a lower limit value based on the traveling load torque and the allowable acceleration,
determine an allowable output torque range to be a range of output torque values between the upper limit value and the lower limit value, the upper limit value and the lower limit value being calculated such that the allowable output torque range is narrower when the work state is an excavation state using the work equipment than when the work state is a traveling state,
correct the required output torque to a corrected required output torque that is included in the allowable output torque range, and
output a control signal to control the drive source based on the corrected required output torque.