# US 8,543,296 B2 · Turning drive control unit and construction machine including same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,543,296 B2 - Document ID: US8543296B2 - Status: Granted - Kind: B2 - Application number: 12/994,551 - Filed: 2008-05-27 - Published: 2011-03-31 - Granted: 2013-09-24 - Earliest claimed: 2008-05-27 - Assignees: Sumitomo(S.H.I.) Construction Machinery Co., Ltd.; Sumitomo Heavy Industries, Ltd. - Applicants: Kiminori Sano - Inventors: Kiminori Sano - Web page: https://patentgrep.com/patent/US8543296B2 ## CPC - B60W 20/13: in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion - B60K 6/48: Parallel type - B60K 25/04: from static or dynamic pressure or vacuum, developed by the engine - B60L 1/003: {to auxiliary motors, e.g. for pumps, compressors} - B60L 1/20: {Energy regeneration from auxiliary equipment} - B60W 10/08: including control of electric propulsion units, e.g. motors or generators - E02F 9/128: {Braking systems} - E02F 9/2075: {of the hybrid type (for vehicles in general B60W20/00)} - E02F 9/2246: {Control of prime movers, e.g. depending on the hydraulic load of work tools} - B60K 1/02: comprising more than one electric motor - B60K 17/10: of fluid gearing - B60L 2200/40: Working vehicles - B60L 2240/421: Speed - B60L 2240/423: Torque - B60W 20/00: Control systems specially adapted for hybrid vehicles {(hybrid vehicle design, B60K6/00; electric vehicles B60L)} - B60W 2510/081: Speed - B60W 2710/083: Torque - B60Y 2200/25: Track vehicles - B60Y 2200/412: Excavators - Y02T 10/62: Hybrid vehicles - Y02T 10/64: Electric machine technologies in electromobility - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) - B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A turning drive control unit configured to control driving of the rotation mechanism of a construction machine driven to turn by an electric motor includes a drive command output part configured to output a speed command driving the electric motor based on the amount of operation input via the operation part of the construction machine; a rotation speed detection part configured to detect the rotation speed of the electric motor; and a drive command generation part configured to generate a drive command driving the electric motor based on the speed command output from the speed command output part and the rotation speed detected by the rotation speed detection part. At a time immediately before a rotation stop of the electric motor, the drive command generation part causes the braking torque of the electric motor to be smaller than before the time immediately before the rotation stop. ## Claims ### Claim 1 A turning drive control unit configured to control driving of a rotation mechanism of a construction machine driven to turn by an electric motor, the turning drive control unit comprising: a speed command output part configured to output a speed command driving the electric motor based on an amount of operation input via an operation part of the construction machine; a rotation speed detection part configured to detect a rotation speed of the electric motor; and a drive command generation part configured to generate a drive command driving the electric motor based on the speed command output from the speed command output part and the rotation speed detected by the rotation speed detection part, wherein at a time immediately before a rotation stop of the electric motor, the drive command generation part causes a braking torque of the electric motor to be smaller than before the time immediately before the rotation stop of the electric motor. ### Claim 2 (depends on 1) The turning drive control unit as claimed in claim 1, further comprising: an operation control part configured to switch the electric motor to a short-circuited state, wherein at the time immediately before the rotation stop of the electric motor, the operation control part causes the braking torque of the electric motor to be smaller than before the time immediately before the rotation stop of the electric motor by switching the electric motor to the short-circuited state. ### Claim 3 (depends on 2) The turning drive control unit as claimed in claim 2, wherein the operation control part is configured to cancel the short-circuited state of the electric motor when the rotation speed detected by the rotation speed detection part becomes zero, and the drive command generation part controls driving of the electric motor based on a zero speed command causing the rotation speed of the electric motor to be zero when the short-circuited state is canceled by the operation control part. ### Claim 4 (depends on 1) The turning drive control unit as claimed in claim 1, further comprising: a drive control stop part configured to stop controlling driving of the electric motor, wherein at the time immediately before the rotation stop of the electric motor, the braking torque of the electric motor is caused to be smaller than before the time immediately before the rotation stop of the electric motor by the drive control stop part stopping controlling the driving of the electric motor. ### Claim 5 (depends on 4) The turning drive control unit as claimed in claim 4, wherein the drive control stop part is configured to cancel a stopped state of controlling the driving when the rotation speed detected by the rotation speed detection part becomes zero, and the drive command generation part controls the driving of the electric motor based on a zero speed command causing the rotation speed of the electric motor to be zero when the rotation speed detected by the rotation speed detection part becomes zero. ### Claim 6 (depends on 1) The turning drive control unit as claimed in claim 1, further comprising: a limiting part configured to limit a value of the drive command in absolute value so that a drive torque generated in the electric motor by the drive command is less than or equal to an allowable value, wherein at the time immediately before the rotation stop of the electric motor, the braking torque of the electric motor is caused to be smaller than before the time immediately before the rotation stop of the electric motor by causing the allowable value of the limiting part to be lower than a regular value. ### Claim 7 (depends on 6) The turning drive control unit as claimed in claim 6, wherein the drive command generation part returns the allowable value of the limiting part to the regular value and controls driving of the electric motor based on a zero speed command causing the rotation speed of the electric motor to be zero when the rotation speed detected by the rotation speed detection part becomes zero. ### Claim 8 (depends on 1) The turning drive control unit as claimed in claim 1, wherein when the amount of operation input via the operation part becomes zero so that the drive command generated in the drive command generation part is caused to be zero, the drive command generation part generates the drive command driving the electric motor at a predetermined low speed until the time immediately before the rotation stop of the electric motor, and at the time immediately before the rotation stop of the electric motor, generates the drive command driving the electric motor based on the speed command output from the speed command output part and the rotation speed detected by the rotation speed detection part, thereby causing the braking torque of the electric motor to be smaller than before the time immediately before the rotation stop. ### Claim 9 (depends on 8) The turning drive control unit as claimed in claim 8, wherein the drive command generation part controls driving of the electric motor based on a zero speed command causing the rotation speed of the electric motor to be zero when the rotation speed detected by the rotation speed detection part becomes zero. ### Claim 10 (depends on 1) A construction machine, comprising: the turning drive control unit as claimed in claim 1.