Electric roller and its parking brake control method and system

Abstract

The present invention relates to an electric roller. To solve the problem that the braking control method of an electric roller affects the operation comfort, an electric roller and its parking braking control method and system are provided. The steps of the parking braking control method include: judging the driving state before the walking operation handle returns to the neutral position and performing corresponding parking braking actions according to the driving state after the walking operation handle returns to the neutral position; performing a flat ground parking braking action and detecting the rotation speed of the walking motor after the walking motor outputs zero torque. If the increase in the rotation speed of the walking motor is less than a predetermined value, parking braking is performed; if the increase in the rotation speed of the walking motor is greater than the predetermined value, the zero torque output limit of the walking motor is released and the driving state of the electric roller is re-determined according to the increasing direction of the rotation speed of the walking motor; performing an uphill braking action or a downhill braking action according to the re-determined driving state. The present invention avoids slipping on slopes when parking on non-flat ground, improving the operation comfort.

Description

Technical Field

[0001] The present invention relates to an electric roller, and more particularly to an electric roller and its parking brake control method and system. Background Art

[0002] The forward and backward movement of the electric roller is controlled by a control handle. When the handle swings forward or backward more, the speed of the roller increases. Correspondingly, when the handle swings back to the middle position, the speed decreases. When the handle swings to the middle position, the roller performs a parking brake. Different parking brake control strategies are adopted according to whether the roller is traveling on an uphill, downhill or flat road surface during parking brake, and finally the parking brake is used to brake the roller.

[0003] Since the electric roller does not have a brake pedal, in order to prevent the roller from slipping when starting on a slope, the torque of the traveling motor when the vehicle speed of the roller is zero is recorded during the previous stop before starting the roller. When starting, the parking brake is released when the torque of the traveling motor reaches the torque recorded during the previous stop.

[0004] When the roller starts on a flat road surface, the parking brake is released immediately after the control handle leaves the middle position. At that time, there are often errors in judging whether the roller is on a flat road surface. If the roller is actually on a slope but misjudged as being on a flat road surface during parking brake, there may be a slipping phenomenon when starting. If the parking brake is released when the torque of the traveling motor reaches a certain value when starting on a flat road surface, the start on a flat road surface is like starting on a slope, which affects the operation comfort. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an electric roller and its parking brake control method and system to avoid slipping and improve operation comfort for the problem that the existing braking control method of the electric roller affects the operation comfort.

[0006] The technical solution for the present invention to achieve its purpose is as follows: A parking brake control method for an electric roller is provided. The traveling motor controller of the electric roller controls the operation of the traveling motor in a speed mode. The parking brake includes an uphill parking brake action, a downhill parking brake action and a flat parking brake action. The steps of the parking brake control method are characterized by including:

[0007] Judging the driving state of the electric roller before the traveling operation handle returns to the middle position and performing corresponding parking brake actions according to the driving state after the traveling operation handle returns to the middle position;

[0008] The ground parking brake action is that when the travel motor speed is less than the set value after the travel operating handle returns to the center, the whole machine controller sends a 0 speed command to the travel motor controller and limits the travel motor to output zero torque through the torque limit command;

[0009] After the parking brake is applied on flat ground and the travel motor outputs zero torque, the travel motor speed is detected. If the travel motor speed increase is less than a preset value, the parking brake is applied; if the travel motor speed increase is greater than a preset value, the travel motor zero torque output restriction is released and the driving state of the electric roller is re-determined according to the direction of the travel motor speed increase; the uphill parking brake or the downhill parking brake is applied according to the re-determined driving state.

[0010] In the present invention, after the flat ground parking brake is performed, the parking brake is not performed immediately, but a check is performed to see whether the electric roller is traveling on a horizontal road surface. If it is confirmed that it is traveling on a horizontal ground, the parking brake is performed. If the test result is that it is traveling on a non-horizontal ground, an uphill braking action or a downhill braking action is performed according to the re-determined driving state, thereby avoiding the use of the flat ground parking brake action to park the machine when traveling on a non-horizontal ground, thereby improving its operating comfort.

[0011] In the parking brake control method for the electric roller, the uphill parking brake action is to perform parking brake when the speed of the travel motor is less than a predetermined value after the travel operating handle returns to the center, and after a predetermined time delay after the parking brake, the whole machine controller sends a 0 speed command to the travel motor controller and limits the travel motor to output zero torque through a torque limit command;

[0012] The downhill parking brake action is that after the travel operating handle returns to the center, the whole machine controller sends a speed specified value instruction in the opposite direction to the travel motor controller, and the parking brake is performed when the travel motor speed is less than the set value. After a predetermined delay after the parking brake, the whole machine controller sends a 0 speed instruction to the travel motor controller and limits the travel motor to output zero torque through a torque limit instruction.

[0013] In the parking brake control method for an electric roller, the travel motor torque is recorded and stored when the travel motor speed is less than a predetermined value during the downhill parking brake action and the uphill parking brake action.

[0014] In the above-mentioned parking brake control method for electric roller,

[0015] Record and store the calibrated torque data of the travel motor of the electric roller at various speeds when the electric roller is traveling at a constant speed on a calibrated horizontal road surface, and use the calibrated torque as a median value to set a reference range of the torque for traveling on flat ground at various speeds;

[0016] The steps to determine the driving state of the electric roller before the walking operation handle returns to the neutral position are to obtain the average speed and average torque of the walking motor within a predetermined time before the walking operation handle returns to the neutral position. If the average torque is greater than the upper limit of the flat driving torque reference range at the average speed of the walking motor, the driving state is presumed to be uphill driving; if the average torque is between the upper limit and the lower limit of the flat driving torque reference range at the average speed of the walking motor, the driving state is presumed to be horizontal driving; if the average torque is less than the lower limit of the flat driving torque reference range at the average speed of the walking motor, the driving state is presumed to be downhill driving.

[0017] In the above electric roller parking brake control method, after the flat parking brake action is performed, if the rotation direction of the walking motor is the same as the rotation direction before the walking operation handle returns to the neutral position, the driving state of the roller is re-determined as downhill driving; if the rotation direction of the walking motor is opposite to the rotation direction before the walking operation handle returns to the neutral position, the driving state of the roller is re-determined as uphill driving.

[0018] In the above electric roller parking brake control method, after the walking operation handle returns to the neutral position, the remaining power of the power battery of the electric roller is obtained. If the remaining power of the power battery is greater than a predetermined value, the reference power is calculated based on the rotation speed and torque of the walking motor before the walking operation handle returns to the neutral position. After the walking operation handle returns to the neutral position, the whole machine controller sends a control command to the pump motor controller to control the rotation speed of the pump motor so that the output power of the pump motor is greater than the reference power, and after the parking brake, the rotation speed of the pump motor is restored to the rotation speed before the walking operation handle returns to the neutral position.

[0019] The technical solution of the present invention to achieve its purpose is as follows: A parking brake control system for an electric roller is provided, characterized in that its whole machine controller includes: a memory and a processor, and the processor is configured to execute the aforementioned parking brake control method based on the instructions stored in the memory.

[0020] The technical solution of the present invention to achieve its purpose is as follows: An electric roller is provided, characterized in that it includes the aforementioned electric roller parking brake control system.

[0021] Compared with the prior art, the present invention avoids the roller from slipping when parking on non-flat ground and improves the operation comfort. Description of the Drawings

[0022] Figure 1 It is a block diagram of the walking control system of the electric drive roller of the present invention.

[0023] Figure 2 It is a flow chart of the uphill parking brake control of the electric drive roller of the present invention.

[0024] Figure 3It is the flowchart of the downhill parking brake control for the electric drive roller of the present invention.

[0025] Figure 4 It is the flowchart of the flat ground parking brake control for the electric drive roller of the present invention.

[0026] Figure 5 It is the flowchart of the parking start control for the electric drive roller of the present invention.

[0027] Figure 6 It is the schematic diagram of the motor torque range in the flat ground driving state of the electric drive roller of the present invention.

[0028] Names and serial numbers of components in the figure:

[0029] Pump motor controller 1, pump motor 2, hydraulic pump 3, travel operation handle 4, whole machine controller 5, parking brake system 6, travel motor controller 7, travel motor 8, gearbox 9, drive axle 10. Specific embodiments

[0030] The following describes the specific implementation manners in conjunction with the drawings.

[0031] As Figure 1 shown, the travel control system of the electric drive roller in this embodiment includes the whole machine controller 5, travel motor 8, pump motor 2, travel operation handle 4, travel motor controller 7, pump motor controller 1, parking brake system 6, etc.

[0032] The travel operation handle 4 is connected to the whole machine controller 5 through the CAN bus and is used to control the travel and braking of the roller. The travel operation handle 4 controls the travel and parking brake of the roller by swinging forward and backward and returning to the middle position. When the travel operation handle 4 swings forward relative to the machine, the travel motor 8 rotates forward; when the travel operation handle 4 swings backward, the travel motor 8 rotates backward. When the travel operation handle 4 returns to the middle position, the parking brake system 6 performs the parking brake operation, and the swing angle of the travel operation handle 4 is linearly corresponding to the target speed of the travel motor 8.

[0033] The travel motor controller 7 is connected to the whole machine controller 5 and the travel motor 8 through the CAN bus. The travel motor controller controls the operation of the travel motor in the speed mode and controls the rotation direction, speed and torque of the travel motor 8 according to the control instruction of the whole machine controller 5.

[0034] The pump motor controller 1 is connected to the whole machine controller 5 and the pump motor 2 through the CAN bus and is used to control the rotation direction, speed and torque of the pump motor 2 according to the control instruction of the whole machine controller 5.

[0035] The pump motor 2 is used to drive the hydraulic pump 3 on the whole vehicle to work, and the hydraulic pump 3 works to provide power for the travel steering and the work of the whole machine working device.

[0036] The parking brake system 6 is connected to the machine controller 5 and is used to perform parking brake or release the parking brake according to the control instructions of the machine controller 5.

[0037] The machine controller obtains the rotational speed and output torque information of the travel motor 8 and the pump motor 2.

[0038] The machine controller 5 includes a memory and a processor.

[0039] The memory is used to store the rotational speed and torque data of the travel motor 8 when the electric drive roller is traveling at a constant speed on a calibrated horizontal road surface, and the travel motor torque information when the rotational speed of the travel motor 8 is less than a predetermined value after the travel operation handle 4 returns to the neutral position each time.

[0040] The processor is configured to control the operation of the travel motor 8 and the pump motor 2 according to a predetermined control strategy based on the state change of the operation handle 4 based on the instructions stored in the memory, and to control the operation of the parking brake system 6.

[0041] The travel motor 8 is a permanent magnet synchronous motor, which is connected to the transmission 9, the transmission 9 is connected to the drive axle 10, and the drive axle 10 drives the rear wheels of the roller to rotate.

[0042] The pump motor 2 is a permanent magnet synchronous motor, which is connected to the hydraulic pump 3 and drives the hydraulic pump 3 to work. It provides power for the operation of the machine working device during the operation process and is used to consume the braking regenerative energy during the travel braking process.

[0043] The steps of the parking brake control method for the electric roller include: judging the travel state of the electric roller before the travel operation handle returns to the neutral position and performing corresponding parking brake actions according to the travel state after the travel operation handle returns to the neutral position. The parking brake includes uphill parking brake actions, downhill parking brake actions, and flat ground parking brake actions.

[0044] The uphill parking brake action is that when the rotational speed of the travel motor is less than a predetermined value after the travel operation handle returns to the neutral position, the machine controller sends a parking instruction to the parking brake system 6 to perform the parking brake, and after a predetermined time delay after the parking brake, the machine controller sends a 0 rotational speed instruction to the travel motor controller and limits the motor output zero torque through a torque limit instruction. Its control flow is as Figure 2 shown.

[0045] The downhill parking brake action is that after the travel operation handle returns to the neutral position, the machine controller sends a rotational speed specified value instruction in the opposite direction to the travel motor controller. When the rotational speed of the travel motor is less than the set value, the machine controller sends a parking instruction to the parking brake system 6 to perform the parking brake, and after a predetermined time delay after the parking brake, the machine controller sends a 0 rotational speed instruction to the travel motor controller and limits the motor output zero torque through a torque limit instruction. Its control flow is as Figure 3 shown.

[0046] When the walking operation handle returns to the neutral position and the rotational speed of the walking motor is less than the set value, the machine controller does not send a parking command to the parking brake system 6 immediately. Instead, it sends a zero-speed command to the walking motor controller and limits the motor output torque to zero through a torque limit command.

[0047] In the memory of the machine controller, there are calibrated speeds and calibrated torques for judging the driving state of the motor roller. The motor roller travels at a constant speed on a calibrated horizontal road surface at various driving speeds, records the rotational speed and torque of the walking motor at each driving speed, and takes the recorded rotational speed and torque as the calibrated speed and calibrated torque. The calibrated torques at each calibrated speed form a calibrated torque curve. Taking the calibrated torque as the median value, a reference interval for the flat driving torque is set, as Figure 6 shown.

[0048] After the walking operation handle returns to the neutral position, the machine controller judges the driving state of the motor roller before the operation handle returns to the neutral position. The steps are as follows: The machine controller obtains the average rotational speed and average torque of the walking motor within a predetermined time before the walking operation handle returns to the neutral position, and compares the average rotational speed and average torque with the calibrated speed and calibrated torque stored in the memory. Specifically, according to the average rotational speed, it searches in the data stored in the memory for the calibrated torque with the same calibrated speed as the average rotational speed, and compares this calibrated torque with the average torque obtained by the machine controller. If the average torque is greater than the upper limit value of the predetermined interval with the calibrated torque as the median value, it is presumed that the driving state is uphill driving; if the average torque is between the upper limit value and the lower limit value of the predetermined interval with the calibrated torque as the median value, it is presumed that the driving state is flat driving; if the average torque is less than the lower limit value of the predetermined interval with the calibrated torque as the median value, it is presumed that the driving state is downhill driving.

[0049] The machine controller sends corresponding control commands according to the driving state of the motor roller when the walking operation handle returns to the neutral position, and performs corresponding parking brake actions. When it is determined to be uphill driving, an uphill parking brake action is performed; when it is determined to be downhill driving, a downhill parking brake action is performed. Finally, for both the uphill parking brake action and the downhill parking brake action, the machine controller controls the parking brake system to perform parking braking.

[0050] When the driving state of the motor roller is determined to be flat driving when the walking operation handle returns to the neutral position, a flat parking brake action is performed. The flat parking brake action does not immediately perform parking braking at the end. Instead, it detects the rotational speed of the walking motor after the walking motor outputs zero torque. If the increase in the rotational speed of the walking motor is less than the predetermined value, the machine controller sends a parking command to the parking brake system 6 to perform parking braking.

[0051] If the increase in the rotational speed of the walking motor is greater than the predetermined value, the zero-torque output limit of the walking motor is released, and the driving state of the motor roller is re-judged according to the increasing direction of the rotational speed of the walking motor.

[0052] If the increasing direction of the walking motor speed is the same as the speed direction before the walking operation handle returns to the neutral position, the traveling state of the roller is re-determined as traveling downhill. If the increasing direction of the walking motor speed is opposite to the speed direction before the walking operation handle returns to the neutral position, the traveling state of the roller is re-determined as traveling uphill.

[0053] The whole machine controller performs the uphill parking brake action or the downhill parking brake action according to the re-determined traveling state. Finally, for the uphill parking brake action or the downhill parking brake action, the whole machine controller sends a parking instruction to the parking brake system 6 to perform the parking brake, and ends the parking brake of the electric roller.

[0054] In the above embodiment, when performing the uphill parking brake action or the downhill parking brake action, when the speed of the walking motor is less than a predetermined value, the whole machine controller records and stores the torque of the walking motor for the next starting operation of the electric roller.

[0055] Each time the walking operation handle leaves the neutral position, if it was traveling uphill before parking and the starting direction is the same, or it was traveling downhill before parking and the starting direction is the opposite, the whole machine controller sends a corresponding speed command to the walking motor controller according to the swing angle of the walking operation handle. When the output torque of the walking motor is greater than or equal to the torque value of the walking motor recorded during the previous parking, the vehicle controller sends a control command to the parking brake system to release the parking brake. If it was traveling downhill before parking and the starting direction is the same or traveling on a horizontal road surface, the whole machine controller sends a corresponding speed command to the walking motor controller according to the swing angle of the walking operation handle, and at the same time releases the parking brake. The starting control of the electric roller is as Figure 5 shown.

[0056] In the above embodiment, when the walking operation handle returns to the neutral position, the power of the power battery is obtained. If the power of the power battery is greater than a predetermined value, the whole machine controller calculates a reference power according to the speed and torque of the walking motor before parking, controls the speed of the pump motor to be a certain speed during parking so that the output power of the pump motor is greater than the reference power, and controls the speed of the pump motor to return to the speed before parking after parking ends.

Claims

1. A parking brake control method for an electric roller, wherein the travel motor controller of the electric roller controls the travel motor to operate in a speed mode, and the parking brake includes uphill parking brake action, downhill parking brake action and flat ground parking brake action. Features The steps of the parking brake control method include: Determine the driving state of the electric roller before the travel operating handle returns to the center and perform corresponding parking brake action according to the driving state after the travel operating handle returns to the center; The ground parking brake action is that when the travel motor speed is less than the set value after the travel operating handle returns to the center, the whole machine controller sends a 0 speed command to the travel motor controller and limits the travel motor to output zero torque through the torque limit command; After the parking brake is applied on flat ground and the travel motor outputs zero torque, the travel motor speed is detected. If the travel motor speed increase is less than a preset value, the parking brake is applied; if the travel motor speed increase is greater than a preset value, the travel motor zero torque output restriction is released and the driving state of the electric roller is re-determined according to the direction of the travel motor speed increase; the uphill parking brake or the downhill parking brake is applied according to the re-determined driving state.

2. The parking brake control method for an electric roller according to claim 1, Features: The uphill parking brake action is to perform parking brake when the speed of the travel motor is less than a predetermined value after the travel operating handle returns to the center, and after a predetermined time delay after the parking brake, the whole machine controller sends a 0 speed command to the travel motor controller and limits the travel motor to output zero torque through a torque limit command; The downhill parking brake action is that after the travel operating handle returns to the center, the whole machine controller sends a speed specified value instruction in the opposite direction to the travel motor controller, and the parking brake is performed when the travel motor speed is less than the set value. After a predetermined delay after the parking brake, the whole machine controller sends a 0 speed instruction to the travel motor controller and limits the travel motor to output zero torque through a torque limit instruction.

3. The parking brake control method for an electric roller according to claim 2, Features In the downhill parking brake action and the uphill parking brake action, when the rotation speed of the travel motor is less than a predetermined value, the travel motor torque is recorded and stored.

4. The parking brake control method for an electric roller according to claim 1, Features After the flat ground parking brake is performed, if the speed increase direction of the travel motor is the same as the speed direction before the travel operating handle returns to the center, the roller's driving state is re-determined to be downhill driving; if the speed increase direction of the travel motor is opposite to the speed direction before the travel operating handle returns to the center, the roller's driving state is re-determined to be uphill driving.

5. The parking brake control method for an electric roller according to claim 1, Features After the walking operation handle returns to the neutral position, obtain the remaining power of the power battery of the electric roller. If the remaining power of the power battery is greater than a predetermined value, calculate the reference power according to the walking motor speed and torque before the walking operation handle returns to the neutral position. After the walking operation handle returns to the neutral position, the whole machine controller sends a control command to the pump motor controller to control the pump motor speed so that the output power of the pump motor is greater than the reference power. After the parking brake, control the pump motor speed to return to the speed before the walking operation handle returns to the neutral position.

6. The electric roller parking brake control method according to any one of claims 1 to 5, characterized in that Record and store the calibrated torque data of the walking motor at each speed when the electric roller is traveling at a constant speed on a calibrated horizontal road surface, and set the flat ground traveling torque reference interval corresponding to each speed with the calibrated torque as the median value; The step of judging the traveling state of the electric roller before the walking operation handle returns to the neutral position is to obtain the average speed and average torque of the walking motor within a predetermined time before the walking operation handle returns to the neutral position. If the average torque is greater than the upper limit of the flat ground traveling torque reference interval at the average speed of the walking motor, it is presumed that the traveling state is uphill; if the average torque is between the upper limit and the lower limit of the flat ground traveling torque reference interval at the average speed of the walking motor, it is presumed that the traveling state is horizontal; if the average torque is less than the lower limit of the flat ground traveling torque reference interval at the average speed of the walking motor, it is presumed that the traveling state is downhill.

7. An electric roller parking brake control system, characterized in that Its whole machine controller includes a memory and a processor, and the processor is configured to execute the parking brake control method according to any one of claims 1-6 based on the control instructions stored in the memory.

8. An electric roller, characterized in that It includes the electric roller parking brake control system according to claim 7.

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