Vehicle supporting and turning control method for electrically-driven rotary excavator
By using traditional signal recognition and torque control, the safety hazards of the support vehicle in the turning process of the electric drive rotary excavator are solved, and a safe and reliable electric drive turning effect is achieved without affecting the acceleration performance.
Patent Information
- Application Number
- CN202511447329.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-11
- Publication Date
- 2025-11-21
AI Technical Summary
Electric-driven rotary excavators pose safety hazards due to errors in working condition identification during the turning process of the support vehicle, especially since the counteracting torque generated by the rotary motor cannot be automatically cleared, affecting driving safety.
The system uses traditional excavator signals for working condition identification. By limiting drive torque and delaying the process, it avoids braking failure caused by misidentification, ensuring safety. It also releases torque limitation when acceleration is intended to maintain acceleration performance.
This technology enables electric rotary excavators to achieve cornering safety and acceleration performance without incurring additional costs, reaching a level of cornering performance similar to traditional models.
Smart Images
Figure CN120990181A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of excavator support vehicle turning control technology, specifically relating to a method for controlling the turning of the support vehicle of an electrically driven rotary excavator. Background Technology
[0002] With increasing global emphasis on environmental protection and sustainable development, the construction and engineering machinery industry is undergoing a profound transformation. Traditional internal combustion engine-driven excavators are facing increasing restrictions due to their high emissions and noise levels. Excavator electrification, as a crucial component of this transformation, is gradually becoming a trend in the industry. Whether the cornering maneuver, a vital operation in the daily work of excavators, can achieve the same performance as traditional models in excavators with electric slewing mechanisms is one of the key factors in the electrification transition of excavators.
[0003] Please see Figure 1 The upper part 3 of the excavator is connected to the lower part 1 through the slewing support mechanism 2. The upper part 3 is connected to the boom 4 and the slewing lever 5. The end of the slewing lever 5 is connected to the bucket 6. The turning of the excavator is an action completed by the simultaneous cooperation of multiple parts of the excavator. During operation, the slewing lever 5 needs to be perpendicular to the ground, the bucket 6 needs to be in contact with the ground, and the boom 4 needs to be pressed down to make the whole vehicle tilt at a certain angle to the ground. With the cooperation of slewing and traveling, the whole vehicle can quickly achieve the purpose of turning on the spot.
[0004] Currently, there are two main challenges in enabling the outrigger to turn on electrically driven rotary excavators: first, how to maximize the identification of outrigger turning conditions under existing vehicle conditions; and second, how to ensure driving safety if misidentification occurs. During the outrigger turning process of an electrically driven rotary excavator, the upper structure remains stationary, the slewing handle is moved in the opposite direction, and the lower structure rotates with the travel drive. When the slewing mechanism is driven by a motor, the slewing motor is dragged in the opposite direction by the travel drive during the outrigger turning process. Simultaneously, the slewing motor generates a counteracting torque, which becomes a stall torque after the turn and cannot be automatically cleared. If the boom is raised at this time, the upper structure will produce an unexpected slewing motion under the action of the stall torque, seriously affecting driving safety. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for controlling the cornering of an electric rotary excavator. This method utilizes existing signals from traditional excavator models for condition identification without incurring significant additional costs. By limiting only the drive torque, it avoids safety issues such as brake failure caused by misidentification of operating conditions. When an acceleration intention is detected, the torque limiting function is actively deactivated, minimizing impact on acceleration performance. This allows the electric rotary excavator to achieve cornering performance similar to that of traditional models.
[0006] The technical solution to achieve the above objective is: a method for controlling the turning of the support carriage of an electrically driven rotary excavator, comprising the following steps:
[0007] S1, Tractor Turning Operation Recognition Steps: The operation recognition module determines whether the excavator is performing a tractor turning operation. The specific process is as follows:
[0008] S11, the working condition identification module determines whether the excavator has a boom lowering action by using the boom handle signal. If there is a boom lowering action, then proceed to step S12.
[0009] S12, the working condition identification module determines whether the walking and slewing actions are performed simultaneously by the slewing handle signal and the walking accelerator pedal signal. If the walking and slewing actions are performed simultaneously, proceed to step S13; if the boom lifting action occurs during this process, return to step S11.
[0010] S13, the working condition identification module determines whether the real-time oil pressure value is greater than the set oil pressure threshold by the boom small chamber oil pressure signal. If the real-time oil pressure value is greater than the set oil pressure threshold, it can be determined that the support vehicle is turning at this time; if there is boom lifting action when the real-time oil pressure value is less than the set oil pressure threshold, then return to step S11.
[0011] S2, Torque Control Step: When the working condition identification module determines that the excavator is performing a cornering operation, the torque control module performs torque control processing based on the actions of the swing handle, travel accelerator pedal, and boom handle to ensure that raising the boom after the cornering operation does not produce unexpected swinging motion. The specific process is as follows:
[0012] S21, the torque control module determines whether one or more of the following four conditions are met by using the boom handle signal, swing handle signal, travel accelerator pedal signal, and motor speed signal:
[0013] 1) Does the boom have a lifting motion?
[0014] 2) Check if the rotary handle has crossed zero or returned to the neutral position;
[0015] 3) Is the motor speed close to zero?
[0016] 4) Check if the travel pedals have returned to the center position;
[0017] If at least one of the above four conditions is met, proceed to step S22;
[0018] S22, the torque control module performs the following two operations simultaneously and sets the delay waiting time:
[0019] 1) Actively limit the motor drive torque to around 0 Nm within 100 ms;
[0020] 2) Increase the deceleration gradient of the target motor speed so that the target motor speed is reduced to 0 rpm within 100 ms;
[0021] If the delay time is met or the torque control module determines through the rotary handle signal that there is an intention to accelerate the rotation, then proceed to step S32.
[0022] S23, the torque control module releases the motor's drive torque limit and restores the motor's target speed deceleration gradient.
[0023] In the above-mentioned method for controlling the turning of the support vehicle of an electric drive rotary excavator, in step S11, the boom action includes boom lowering action, boom raising action, and no boom action. The boom action is determined by the position of the boom handle. When the boom handle is in the middle position, it is determined that there is no boom action. If the boom handle is set to move forward for boom lowering action, then the boom handle is set to move backward for boom raising action.
[0024] In the above-mentioned method for controlling the turning of the support vehicle of an electric-driven rotary excavator, step 12 determines whether there is any movement of the rotary and travel by checking whether the position signals of the rotary handle and the travel pedal are in the neutral position. If the position signals of the rotary handle and the travel pedal are in the neutral position, then there is no movement of the rotary and travel vehicles; if the position signals of the rotary handle and the travel pedal are not in the neutral position, then it is determined that the movement and rotary actions are performed simultaneously.
[0025] In the above-mentioned method for controlling the cornering of the support vehicle of an electrically driven rotary excavator, in step 13, the hydraulic pressure threshold of the boom chamber is selected as the midpoint between the maximum hydraulic pressure during boom descent and the minimum hydraulic pressure during support vehicle movement.
[0026] In the above-mentioned method for controlling the turning of the support vehicle of an electrically driven rotary excavator, in step S22, the delay waiting time is set to 100-200ms, and the torque control module completes the two operations within the delay waiting time.
[0027] In the above-mentioned method for controlling the turning of the support vehicle of an electric drive rotary excavator, in step S22, the torque control module determines whether there is an intention to accelerate the rotation by means of the rotation handle signal as follows: The torque control module first calculates the speed deviation between the target speed and the actual speed of the motor; if the calculated speed deviation is in the same direction as the actual speed, it can be determined that there is an intention to accelerate the rotation at this time.
[0028] The method for controlling the turning of the support carriage in an electrically driven rotary excavator according to the present invention has the following beneficial effects:
[0029] (1) Use the existing signals of traditional excavator models for working condition identification without incurring significant additional costs;
[0030] (2) By using the method of limiting only the driving torque, safety issues such as braking failure can be avoided in the event of misidentification of the working conditions;
[0031] (3) When an acceleration intention is detected, the torque limiting function is actively deactivated, which will not have a significant impact on acceleration performance.
[0032] (4) This enables the electric rotary excavator to achieve similar turning performance to traditional models. Attached Figure Description
[0033] Figure 1 This is a simplified structural diagram of an excavator;
[0034] Figure 2 This is a flowchart of the support vehicle turning control method of the electric drive rotary excavator of the present invention;
[0035] Figure 3 A flowchart illustrating the steps for identifying vehicle turning conditions.
[0036] Figure 4 This is a flowchart illustrating the torque control process. Detailed Implementation
[0037] To enable those skilled in the art to better understand the technical solution of the present invention, its specific embodiments are described in detail below with reference to the accompanying drawings:
[0038] Please see Figure 2 , Figure 3 and Figure 4 The preferred embodiment of the present invention is a method for controlling the turning of the support vehicle of an electrically driven rotary excavator, which includes a step of identifying the turning condition of the support vehicle and a step of torque control.
[0039] S1, Cross-Tractor Turning Condition Recognition Steps: Cross-tractor turning condition recognition requires the following signals: boom chamber hydraulic pressure signal, boom handle signal, swing handle signal, and travel accelerator pedal signal. Cross-tractor turning conditions have three distinct characteristics: 1) During the preparation phase, the boom is lowered, causing the entire excavator to form a certain angle with the ground; 2) During the turning process, travel and swing are performed simultaneously; 3) During the cross-tractor operation, the bucket generates significant pressure against the ground, which can be reflected in changes in the boom chamber hydraulic pressure. The condition recognition module determines whether the excavator is performing a cross-tractor turning operation. The specific process is as follows:
[0040] S11, the working condition identification module determines whether the excavator has a boom lowering action through the boom handle signal. If there is a boom lowering action, proceed to step S12. Boom actions include boom lowering action, boom raising action, and no boom action. The boom action is determined by the position of the boom handle. If the boom handle is in the middle position, it is determined that there is no boom action. If the boom handle is set to move forward for boom lowering action, then the boom handle is set to move backward for boom raising action.
[0041] S12, the working condition identification module determines whether the walking and slewing actions are occurring simultaneously by using the slewing handle signal and the travel accelerator pedal signal. If the walking and slewing actions are occurring simultaneously, proceed to step S13; if a boom lifting action occurs during this process, return to step S11. The determination of whether there is a slewing and walking action is made by checking whether the position signals of the slewing handle and the travel pedal are in the neutral position. If the position signals of the slewing handle and the travel pedal are in the neutral position, then there is no corresponding slewing and walking action; if the position signals of the slewing handle and the travel pedal are not in the neutral position, then it is determined that the walking and slewing actions are occurring simultaneously.
[0042] S13, the working condition identification module determines whether the real-time oil pressure value is greater than the set oil pressure threshold by the boom small cavity oil pressure signal. If the real-time oil pressure value is greater than the set oil pressure threshold, it can be determined that the support vehicle is turning at this time. If there is a boom lifting action when the real-time oil pressure value is less than the set oil pressure threshold, the process returns to step S11. The oil pressure threshold of the boom small cavity is selected as the midpoint between the maximum oil pressure during boom descent and the minimum oil pressure during support vehicle operation.
[0043] S2, Torque Control Step: When the working condition identification module determines that the excavator is performing a cornering operation, the torque control module performs torque control processing based on the actions of the swing handle, travel accelerator pedal, and boom handle to ensure that raising the boom after the cornering operation does not produce unexpected swinging motion. The specific process is as follows:
[0044] S21, the torque control module determines whether one or more of the following four conditions are met by using the boom handle signal, swing handle signal, travel accelerator pedal signal, and motor speed signal:
[0045] 1) Does the boom have a lifting motion?
[0046] 2) Check if the rotary handle has crossed zero or returned to the neutral position;
[0047] 3) Is the motor speed close to zero?
[0048] 4) Check if the travel pedals have returned to the center position;
[0049] If at least one of the above four conditions is met, proceed to step S22;
[0050] S22, the torque control module performs the following two operations simultaneously and sets a delay time of 100-200ms. The torque control module completes the following two operations within the delay time:
[0051] 1) Actively limit the motor drive torque to around 0 Nm within 100 ms;
[0052] 2) Increase the deceleration gradient of the target motor speed so that the target motor speed is reduced to 0 rpm within 100 ms;
[0053] If the delay time is met or the torque control module determines through the rotary handle signal that there is an intention to accelerate the rotation, then proceed to step S32.
[0054] The torque control module determines whether there is an intention to accelerate rotation by using the rotary handle signal as follows: The torque control module first calculates the speed deviation between the target speed and the actual speed of the motor; if the calculated speed deviation is in the same direction as the actual speed, it can be determined that there is an intention to accelerate rotation.
[0055] S23, the torque control module releases the motor's drive torque limit and restores the motor's target speed deceleration gradient.
[0056] In summary, the outrigger turning control method for the electric rotary excavator of the present invention uses existing signals from traditional excavator models for working condition identification without incurring significant additional costs; by limiting only the drive torque, it avoids safety issues such as brake failure caused by misidentification of working conditions; when an acceleration intention is detected, the torque limiting function is actively deactivated, which does not significantly affect acceleration performance; thus, the electric rotary excavator can achieve outrigger turning performance similar to that of traditional models.
[0057] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.
Claims
1. A method for controlling the turning of the support carriage of an electrically driven rotary excavator, characterized in that, Includes the following steps: S1, Tractor Turning Operation Recognition Steps: The operation recognition module determines whether the excavator is performing a tractor turning operation. The specific process is as follows: S11, the working condition identification module determines whether the excavator has a boom lowering action by using the boom handle signal. If there is a boom lowering action, then proceed to step S12. S12, the working condition identification module determines whether the walking and slewing actions are performed simultaneously by the slewing handle signal and the walking accelerator pedal signal. If the walking and slewing actions are performed simultaneously, proceed to step S13; if the boom lifting action occurs during this process, return to step S11. S13, the working condition identification module determines whether the real-time oil pressure value is greater than the set oil pressure threshold by the boom small chamber oil pressure signal. If the real-time oil pressure value is greater than the set oil pressure threshold, it can be determined that the support vehicle is turning at this time; if there is boom lifting action when the real-time oil pressure value is less than the set oil pressure threshold, then return to step S11. S2, Torque Control Step: When the working condition identification module determines that the excavator is performing a cornering operation, the torque control module performs torque control processing based on the actions of the swing handle, travel accelerator pedal, and boom handle to ensure that raising the boom after the cornering operation does not produce unexpected swinging motion. The specific process is as follows: S21, the torque control module determines whether one or more of the following four conditions are met by using the boom handle signal, swing handle signal, travel accelerator pedal signal, and motor speed signal: 1) Does the boom have a lifting motion? 2) Check if the rotary handle has crossed zero or returned to the neutral position; 3) Is the motor speed close to zero? 4) Check if the travel pedals have returned to the center position; If one or more of the above four conditions are met, proceed to step S22; S22, the torque control module performs the following two operations simultaneously and sets the delay waiting time: 1) Actively limit the motor drive torque to around 0 Nm within 100 ms; 2) Increase the deceleration gradient of the target motor speed so that the target motor speed is reduced to 0 rpm within 100 ms; If the delay time is met or the torque control module determines through the rotary handle signal that there is an intention to accelerate the rotation, then proceed to step S32. S23, the torque control module releases the motor's drive torque limit and restores the motor's target speed deceleration gradient.
2. The method for controlling the turning of the support carriage of an electrically driven rotary excavator according to claim 1, characterized in that, In step S11, the boom action includes boom lowering action, boom raising action, and no boom action. The boom action is determined by the position of the boom handle. When the boom handle is in the middle position, the boom is determined to be in no action. If the boom handle is set to move forward for boom lowering action, then the boom handle is set to move backward for boom raising action.
3. The method for controlling the turning of the support carriage of an electrically driven rotary excavator according to claim 1, characterized in that, In step 12, it is determined whether there is any rotation or walking action by checking whether the position signals of the rotation handle and the walking pedal are in the middle position. If the position signals of the rotation handle and the walking pedal are in the middle position, then there is no rotation or walking action; if the position signals of the rotation handle and the walking pedal are not in the middle position, then it is determined that the walking and rotation actions are performed simultaneously.
4. The method for controlling the turning of the support carriage of an electrically driven rotary excavator according to claim 1, characterized in that, In step 13, the oil pressure threshold of the boom chamber is selected as the midpoint between the maximum oil pressure during boom descent and the minimum oil pressure during vehicle support.
5. The method for controlling the turning of the support carriage of an electrically driven rotary excavator according to claim 1, characterized in that, In step S22, the delay waiting time is set to 100-200ms, and the torque control module completes the two operations within the delay waiting time.
6. The method for controlling the turning of the support carriage of an electrically driven rotary excavator according to claim 1, characterized in that, In step S22, the torque control module determines whether there is an intention to accelerate rotation by using the rotary handle signal as follows: The torque control module first calculates the speed deviation between the target speed and the actual speed of the motor; if the calculated speed deviation is in the same direction as the actual speed, it can be determined that there is an intention to accelerate rotation.