Method for controlling driving behavior of work machine
By detecting driver commands and battery charging information, and automatically selecting regenerative braking or mechanical braking, the problems of uneven driving behavior and large wear of mechanical brakes in the prior art are solved, and more efficient braking mode selection and battery management are achieved.
Patent Information
- Application Number
- CN202380075420.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-11-11
- Filing Date
- 2023-11-08
- Publication Date
- 2025-05-27
AI Technical Summary
When controlling the driving behavior of working machinery, it is difficult to effectively combine regenerative braking and mechanical braking, resulting in uneven driving behavior and large wear of mechanical brakes.
By detecting the driver's driving command and the maximum charging current information of the battery, the desired braking torque and maximum braking torque are determined, and when comparing the two, select a suitable braking method, including the drive motor for regenerative braking or sending a signal to drive the mechanical brake.
It realizes that the appropriate braking method is automatically selected under different braking needs, ensuring smooth driving behavior of the working machinery, reducing wear of the mechanical brakes, and optimizing the charging and discharging efficiency of the battery.
Smart Images
Figure CN120051390A_ABST
Abstract
Description
Technical field
[0001] The present invention relates to a method for controlling the driving behavior of a work machine. Furthermore, the present invention also relates to a control device which is configured to implement a method for controlling the driving behavior of a work machine. Additionally, the present invention also relates to a drive assembly having such a control device and a work machine having such a drive assembly. Background art
[0002] Vehicles with a regenerative function are known from the prior art, in which the vehicle is automatically decelerated by regeneration when the accelerator pedal is released. When the brake pedal of the vehicle is lightly depressed, braking is first achieved by means of regeneration. When the brake pedal is depressed more forcefully, braking is achieved by means of the mechanical vehicle brake. Summary of the invention
[0003] In a first aspect, the present invention relates to a method for controlling the driving behavior of a work machine. The work machine can be an agricultural machine, a construction machine or a transport machine. For example, the construction machine is a wheel loader. The wheel loader can be an electrically driven wheel loader, wherein both the propulsion and the working equipment (such as a lifting mechanism) can be electrically driven. The lifting mechanism can be driven by means of a lifting hydraulic device, which can have a pump driven by an electric motor. The driving behavior of the work machine can be the longitudinal acceleration and alternatively or additionally the lateral acceleration of the work machine. The work machine has a battery, an electric motor for propelling the work machine and a mechanical brake. The battery can be provided for driving the propulsion and working equipment of the work machine. The battery can be a lithium-ion battery for storing electrical energy in the form of chemical energy.
[0004] The electric motor can have an electric motor such as a synchronous motor or an asynchronous motor. The electric motor can operate in a generator and an electric motor mode. The electric motor can be configured to propel the work machine using battery energy, for example by means of a transmission. For example, a multi-stage transmission and alternatively or additionally a continuously variable transmission can be provided. The work machine can have exactly one or alternatively multiple electric motors for propelling the work machine. For example, multiple electric motors for propelling the work machine can be provided, wherein one work machine for propulsion can be provided for each drive wheel or alternatively for each drive axle. The electric motor can have an inverter. The inverter can be configured to convert the direct current of the battery into alternating current for the electric motor. Alternatively or additionally, the inverter can also be used to convert the alternating current provided by the electric motor into direct current of the battery. The electric motor is configured to charge the battery with a charging current by means of regeneration (for example via the inverter). Here, kinetic energy can be converted into electrical energy by means of regeneration. The electrical energy can be stored in the battery in the form of chemical energy.
[0005] The mechanical brake can have multiple-disc brakes, such as wet multiple-disc brakes. The mechanical brake can be adjusted steplessly. The mechanical brake can be set up for braking the forward movement of the working machine. The working machine can have exactly one or alternatively multiple mechanical brakes for braking the forward movement of the working machine. In addition, the working machine can have a control device for implementing the method described below for controlling the driving behavior of the working machine. Here, the control device can be electronically connected to other control devices of the working machine, as well as to the battery and the electric motor for propelling the working machine.
[0006] The method has the step of detecting information on the driver's driving instructions for the working machine. Detecting the information can include receiving the information on the driving instructions. The information on the driver's driving instructions for the working machine can be detected by means of sensors of the working machine. The driving instructions can relate to the desired longitudinal and alternatively or additionally lateral accelerations of the working machine. The driving instructions can include active deceleration and alternatively or additionally acceleration of the working machine. The desired deceleration can be opposite to the current driving direction of the working machine, for example until it stops, and even until it reverses, i.e., until the current driving direction of the working machine is reversed. Here, the driver's driving instructions can be detected directly, for example by means of sensors coupled to operating elements. Alternatively or additionally, however, the driver's driving instructions can also be detected indirectly, for example by detecting parameters that have a clearly defined correlation with the driver's driving instructions.
[0007] The method also has the step of detecting information on the maximum charging current of the battery. Detecting the information on the maximum charging current of the battery can include receiving this information. The information on the maximum charging current can be detected by means of sensors of the working machine. The detection can include actively querying the information on the maximum charging current. Detecting the information on the maximum charging current of the battery can include actively sending the information on the maximum charging current of the battery. The detection can be realized in a time-controlled and alternatively or additionally event-controlled manner. The information on the maximum charging current of the battery can include the absolute value and alternatively or additionally the relative value of the maximum charging current of the battery. The information on the maximum charging current of the battery can include the maximum charging power of the battery. In this step, the maximum charging current can be detected directly or also indirectly with respect to parameters that have a clearly defined correlation with the maximum charging current. The maximum charging current can depend on the battery type, the state of charge (i.e., the current capacity of the battery), environmental parameters (such as the ambient temperature), and other parameters.
[0008] The method further has a step of determining information on a desired braking torque depending on information on a detected driver driving instruction. Determining information on the desired braking torque may include determining the desired braking torque in Newton meters. Determining information on the desired braking torque may include determining a desired negative acceleration of the work machine. Then, based on the desired acceleration and other vehicle data (such as vehicle mass), the desired braking torque can be calculated. The method further has a step of determining information on a maximum braking torque of the electric machine depending on information on a maximum charging current of the detected battery. Determining information on the maximum braking torque may include determining the maximum braking torque in Newton meters. Determining information on the maximum braking torque may include determining a maximum negative acceleration of the work machine. Determining information on the maximum braking torque may include determining a charging current matching therewith. The maximum braking torque can be determined such that this maximum braking torque can be generated by the electric machine by means of regeneration with the maximum charging current. The method further has a step of comparing information on the desired braking torque with information on the maximum braking torque. For example, comparing the desired braking torque with the maximum braking torque can be implemented. Here, the absolute values of the desired braking torque and the maximum braking torque can be compared with each other.
[0009] The method further has a step that, if the desired braking torque is greater than the maximum braking torque, a signal for actuating the mechanical brake is sent. Alternatively, the method has a step that, if the desired braking torque is greater than the maximum braking torque, the mechanical brake is directly controlled. Sending the control signal can be implemented after determining the signal. Actuating the mechanical brake can be implemented such that braking is achieved by the mechanical brake with at least a small part of the desired braking torque or especially with the entire desired braking torque.
[0010] By means of the method, a driving behavior of the work machine independent of the braking torque that can be provided by regeneration can be achieved. If the desired braking torque cannot be provided by means of regeneration, braking is achieved using the mechanical brake. Thus, a smooth driving behavior can be provided, wherein the desired braking torque can be generated at least by means of the mechanical brake.
[0011] According to another embodiment, the method is characterized in that if the desired braking torque is greater than the maximum braking torque, the method includes: driving and controlling the motor to brake with a regenerative braking torque. Herein, the motor, in particular the inverter of the motor, can be driven and controlled such that the regenerative braking torque can be controlled by means of a controllable resistance of the motor, in particular the inverter. Driving and controlling the motor to brake with a regenerative braking torque can be driving and controlling the motor to regenerate. According to the another embodiment, sending a signal for driving and controlling the mechanical brake may further include sending a braking torque difference. Herein, by means of an adjustable pressure of the mechanical brake, the braking torque difference can be controlled on the mechanical brake. Herein, the braking torque difference can be the difference between the desired braking torque and the regenerative braking torque. Here, the regenerative braking torque can be less than or equal to the maximum braking torque. Driving and controlling the motor to regenerate and sending a signal for driving and controlling the mechanical brake can be implemented in parallel here. If the desired braking torque is less than or equal to the maximum braking torque, the method may further have the step of driving and controlling the motor to regenerate. Additionally, if the desired braking torque is less than or equal to the maximum braking torque, when driving and controlling the motor to regenerate, a signal for driving and controlling the mechanical brake can also be implemented. Thereby, braking by means of regeneration can be additionally supported by means of the mechanical brake.
[0012] A method for controlling the driving behavior of a work machine has been shown, wherein, regardless of whether a signal for driving and controlling a mechanical brake or driving and controlling the motor to brake is sent, ensuring that the driving behavior of the work machine remains unchanged during braking is achieved. Herein, if the desired braking torque is greater than the maximum braking torque, the braking of the work machine can be achieved solely or mainly by driving and controlling the mechanical brake. If the desired braking torque is less than or equal to the maximum braking torque, the braking of the work machine can be achieved solely or mainly by driving and controlling the motor to regenerate. Herein, when the driver drives the work machine using this method for controlling the driving behavior of the work machine, it may not be possible to distinguish whether the braking is achieved based on driving and controlling the mechanical brake or based on driving and controlling the motor to brake (i.e., regenerating). A driving behavior that remains unchanged can be generated regardless of whether braking is by means of the mechanical brake or by means of regeneration. Depending on whether a sufficient charging current can be sent to the battery, it is determined by means of the method whether to drive and control the mechanical brake or the motor and to what extent. The method for controlling the driving behavior of a work machine can be used to achieve a particularly resource-saving driving behavior of the work machine. Even in the case where the desired braking torque is greater than the maximum braking torque, herein, regeneration can be achieved to the extent allowed by the maximum braking torque and thus the maximum battery charging current. At the same time, braking completely by means of the mechanical brake with the desired braking torque can be cancelled. Thereby, the mechanical wear of the mechanical brake can also be reduced.
[0013] According to another embodiment, braking is performed with a constant braking torque difference over time by sending a signal for actuating a mechanical brake. For example, the braking torque difference can be approximately 80% of the desired braking torque. Here, the mechanical brake can be actuated such that it constantly provides 80% of the desired braking torque over time. According to this other embodiment, the motor is actuated to brake with a regenerative braking torque that varies over time. The regenerative braking torque can be, for example, approximately 20% of the desired braking torque (by combining the braking torque difference). However, with respect to the variability over time, this 20% of the desired braking torque can fluctuate up and down.
[0014] During braking, for example, it can respond to a change in the inclination of the ground on which the work machine is traveling. The control signal for the mechanical brake can always be sent such that the mechanical brake provides a constant braking torque difference. Then the motor can be actuated to regenerate such that it variably provides the regenerative braking torque over time, and thus can dynamically respond to changes in environmental parameters, such as the ground inclination. Thus, a method for controlling the driving behavior of a work machine for different situations is provided.
[0015] According to another embodiment, the maximum charging current of the battery can depend on the battery state. The battery state can depend on external influences. Here, the external influences can be, for example, temperature or pressure. The battery state can include the aging state of the battery. The battery state can include the state of charge of the battery. The battery state can include the maximum charging capacity of the battery. In a battery that is newly produced and stored at an optimized temperature, if the relative state of charge of the battery is low (e.g., 10% of the maximum battery capacity), there is a relatively high maximum charging current. If the relative state of charge is high, e.g., 80 - 90% of the maximum battery capacity, the maximum charging current may be small. Alternatively, if there is a particularly low or high temperature, or if the battery is particularly aged, the charging current may also be small.
[0016] Thus, the method can respond to changes in the battery state, such as changes in the state of charge of the battery. Then, the method can also be used for work machines with batteries in a non-optimized state. The method can respond dynamically to, for example, battery aging, batteries within a non-optimized temperature range, or highly charged batteries. Thus, the method can be used for a wide range of work machines having batteries for propulsion and regeneration. In this way, work machines with aged or relatively small batteries (i.e., small maximum capacity) can be operated resource-efficiently. The expensive over-sizing of the battery can be dispensed with because smaller batteries can be applied, resulting in a similar driving behavior. If this method for controlling the driving behavior is not used, batteries with a larger capacity and thus a larger maximum charging current must be used in order to provide the same driving behavior over a wide range of states of charge. Using the method can optimize the full utilization of the existing battery, while the driving behavior remains unchanged at the same time.
[0017] According to another embodiment, the information for detecting the driving instruction can include detecting the position information of the pedal and detecting the position information of the travel direction switch. Here, the work machine can include a pedal and a travel direction switch. In particular, the work machine can have only one pedal. Thus, one-pedal-driving can be achieved in combination with the travel direction switch.
[0018] According to another embodiment, the method may further include determining a desired travel direction depending on the position information of the detected travel direction switch. The position information of the detected travel direction switch may include information on the desired travel direction, i.e., the direction in which the driver wants to travel. Here, for example, the driver may operate the travel direction switch from forward to reverse, and thus, the desired travel direction may be reverse. The desired travel direction may include a change in the position of the travel direction switch. Here, the detection of the position information of the travel direction switch may be performed once at the start of the method for controlling the travel behavior. Here, the determined position of the travel direction switch may be detected, and the method may be performed depending on this one-time detection of the travel direction switch position. For example, the driver's willingness to decelerate may be detected by a change in the direction of the travel direction switch. The information for determining the desired braking torque may be achieved depending on the determined desired travel direction. In addition, according to this embodiment, the method may further include detecting information on the current travel direction. The detection of the information on the current travel direction may be achieved depending on the detection of the current travel speed. According to the embodiment, if the direction of the desired travel direction is different from the current travel direction, the method may further include driving the motor to accelerate the working machine in the direction of the desired travel direction. Here, driving the motor to accelerate the working machine may be achieved after sending a signal for driving the mechanical brake and alternatively or additionally after driving the motor to regenerate. Driving the motor for acceleration may be achieved such that acceleration is achieved after braking by the electric motor and alternatively or additionally after braking by the mechanical brake.
[0019] Thereby, the method can also be used for reversing, i.e., from forward travel to reverse travel and vice versa. Here, the driver cannot distinguish whether the deceleration of the working machine is achieved by regeneration or by braking with the mechanical brake. Thus, the travel behavior is smooth, regardless of whether the braking is mechanically or electrically implemented.
[0020] According to another embodiment, the method may further include determining a driving requirement depending on the detected position information of the pedal, wherein determining a driving speed may be included. The detected position information of the pedal may include driving requirement information, that is, how fast the driver wishes to drive in one direction. There may be a driver driving requirement, for example, when the driver stops stepping on the pedal. In addition, the driving requirement may also include stepping on the pedal. Here, the detection of the position information of the pedal may be performed once at the start of the driving behavior control method. Here, the determined position of the pedal may be detected, and the method may be performed depending on this one-time detection of the position of the pedal. The information for determining the desired braking torque may be achieved depending on the determined driving requirement. Determining the desired braking torque may be achieved depending on the determined driving speed. In the case of a higher driving speed in a direction opposite to the current driving direction, a higher desired braking torque may be determined. Alternatively or additionally, determining the desired braking torque may depend on the current driving speed of the work machine. Thus, at a higher driving speed, a greater desired braking torque may be determined.
[0021] Thus, a method is shown in which the driver actively predefines the driving direction and the driving speed, and here, the desired braking torque can be determined indirectly. In this way, the driver can influence the driving behavior of the work machine particularly simply by single-pedal driving. For example, the driver can switch the driving direction switch from forward to reverse during forward driving and maintain the position of the pedal. Thereby, the driving instruction includes reversing the work machine from forward driving to reverse driving with the same absolute speed. Here, braking can be automatically achieved by the method based on the reversal of the work machine. The driver cancels active braking, for example, by the brake pedal. The direction of the driving direction can be determined by the driving direction switch, and the magnitude of the absolute speed can be adjusted by the degree of stepping on the pedal.
[0022] According to another embodiment, a signal for actuating the mechanical brake is sent to a vehicle control device for actuating the mechanical brake. The signal transmission may be achieved via a vehicle bus (such as CAN or Flexray). Here, the vehicle control device may be separate from the control device capable of performing the method.
[0023] Thus, the control devices may be separate, wherein one control device realizes the actuation of the mechanical brake and another control device realizes the actuation of the motor for regeneration. Thus, the responsibility for actuating the mechanical brake can be transferred from the control unit (which performs the method for controlling the driving behavior of the work machine). Thus, it can be stipulated that the special safety requirements for actuating the mechanical brake can be transferred to another control unit, here the vehicle control device. Alternatively, the control device for performing the method for controlling the driving behavior of the work machine may also directly perform the actuation of the mechanical brake.
[0024] In a second aspect, the present invention relates to a control device configured to implement a method for controlling the driving behavior of a work machine according to one of the embodiments of the first aspect.
[0025] In a third aspect, the present invention relates to a drive assembly having an electric motor and a control device according to the second aspect of the invention. Here, the electric motor may have an inverter.
[0026] In a fourth aspect, the present invention relates to a work machine having a battery, a mechanical brake, a vehicle control device for actuating the mechanical brake, and a drive assembly according to the third aspect of the present invention. Here, the work machine may be a construction machine, an agricultural machine, or a transport machine. Here, the work machine may be a non-road vehicle. The work machine according to these aspects of the present invention may be used to implement a method according to an embodiment of the first aspect of the present invention, wherein the work machine may also be used to implement other mentioned steps, such as actuating the mechanical brake, braking by means of the electric motor and by means of the mechanical brake. Description of the Drawings
[0027] Figure 1 Schematically shows a work machine according to an embodiment of the present invention.
[0028] Figure 2 Schematically shows according to Figure 1 the embodiment of the drive assembly of the work machine.
[0029] Figure 3 Schematically shows the method steps for controlling the driving behavior of the work machine according to Figure 1 the work machine.
[0030] Figure 4 Shows according to Figure 1 the characteristic curve of the battery of the work machine. Detailed Description of the Invention
[0031] Figure 1 Schematically shows a work machine 2 according to an embodiment of the present invention. The work machine 2 has a drive assembly 18, a battery 4, a mechanical brake 8, a vehicle control device 16, a pedal 10, and a travel direction switch 12, as Figure 2As shown. The drive assembly 18 has a control device 14 and an electric motor 6. The pedal 10 and the travel direction switch 12 are electronically connected to the vehicle control device 16. The mechanical brake 8 is also electronically connected to the vehicle control device 16. The vehicle control device 16 is configured to drive the mechanical brake 8 and to detect the information of the pedal 10 and the travel direction switch 12, through which the driver can input driving instructions. The pedal 10 and the travel direction switch 12 send electronic signals to the vehicle control device 16. The vehicle control device 16 is electronically connected to the control device 14 of the drive assembly 18. The control device 14 is also electronically connected to the battery 4 and the electric motor 6. The electric motor 6 has an inverter not shown in the drawing and is electrically connected to the battery 4. The electric motor 6 can be driven by the energy stored in the battery 4 and regenerate the energy into the battery 4.
[0032] The control device 14 is configured to implement the method described below for controlling the driving behavior of the work machine 2 with reference to Figure 3 and Figure 4 In the first step S1, information on the driving instructions of the driver of the work machine 2 is detected. In this step S1, in step S1.1, the position information of the pedal 10 is detected, and in step S1.2, the position information of the travel direction switch 12 is detected. The position of the pedal 10 and the position information of the travel direction switch 12 are detected by means of the vehicle control device 16 and transmitted to the control device 14, and these information are read by the control device 14.
[0033] In another step S2, the method has detecting information on the maximum charging current of the battery 4. Here, the maximum charging current of the battery 4 depends on the state of charge of the battery 4. Figure 4 Shows the charge / discharge power B of the battery 4 changing with the state of charge A of the battery 4. Here, the curve C shows the charging power of the battery 4 depending on the state of charge of the battery 4, where the curve D shows the discharge power of the battery 4 depending on the state of charge of the battery 4. Before reaching the value F of the maximum state of charge of the battery regarding the optimized charging power, the charging power B of the battery 4 increases with the increase of the state of charge A. Since this value F, the charging power B of the battery 4 decreases with the increase of the state of charge A through the value G (which represents the maximum state of charge of the battery 4 by regenerative charging) to the value H (which represents the maximum state of charge of the battery 4 for charging). Here, the value I represents the maximum state of charge of the battery, about 100%. The states of charge G and H are both less than the state of charge I. The curve D of the discharge power of the battery 4 extends along the small values (close to zero) of the state of charge of the battery 4, and since the value E (which represents the minimum state of charge of the battery 4 for discharging) starts, it first increases significantly and then slowly increases with the increase of the state of charge until reaching the maximum state of charge I.
[0034] In the step of detecting the information of the maximum charging current of the S2 battery 4, the control device 14 in the present embodiment queries the battery 4: the current state of charge A of the battery 4. Here, depending on the current state of charge, the maximum charging power B and thus the maximum charging current of the battery 4 can be determined, for example, by the Figure 4 shown correlation. For this purpose, the Figure 4 shown correlation is stored in the memory of the control device 14.
[0035] In step S3.1, the information of the desired braking torque is determined depending on the information of the detected driver driving instruction in step S1. Here, in the present embodiment, the desired braking torque in Newton meters is determined. Depending on the position of the pedal 10 and the position of the travel direction switch 12 detected in step S1, the determination of the desired travel direction S3.2 and the determination of the travel requirement S3.3 are realized. The travel requirement may be the travel speed. The determination of the desired braking torque S3.1 depends on the desired travel direction determined in step S3.2 and the travel requirement determined in step S3.3. In step S4, the information of the maximum braking torque of the electric motor 6 is determined. Here, in the present embodiment, the maximum braking torque (in Newton meters) of the electric motor 6 is determined depending on the information of the Figure 4 correlation.
[0036] Subsequently, the comparison S5 of the braking torque determined in step S3.1 with the maximum braking torque determined in step S4 is realized. Thus, the desired braking torque of the driver is compared with the maximum braking torque provided by the electric motor 6.
[0037] If the desired braking torque is less than or equal to the maximum braking torque, then in step S7, the electric motor 6 is driven to regenerate. For this purpose, for example, the inverter of the electric motor 6 can be driven accordingly. In this case, only the electric motor 6 brakes by means of regeneration. If it is obtained in the comparison step S5 that the desired braking torque is greater than the maximum braking torque, the method further includes the step S6 of sending a signal for driving the mechanical brake 8. For example, the driver requests a greater braking torque than the braking torque that the electric motor 6 can provide by means of regeneration. This maximum braking torque is very small, for example, when the battery 4 is in a relatively high state of charge A, as Figure 4 shown. In this case, the electric motor 6 is driven to regenerate in step S7, so as to further convert the braking energy into electrical energy and protect the mechanical brake 8. In particular, the method of the present embodiment also utilizes the region of the relatively high state of charge of the battery 4 between F and G, in Figure 4This is shown in. Additionally, in step S6, the mechanical brake 8 is also actuated by the control device 14, which provides the difference between the desired braking torque and the maximum braking torque of the battery 4. The method can thus achieve using a battery with a relatively high state of charge while obtaining a smooth driving behavior for the driver despite regeneration.
[0038] For example, if the driver requests a change in the driving direction via the driving direction switch 12, which is detected in step S3.2, then after braking (which can be achieved by regeneration through the electric motor 6 and the battery 4 as well as by the mechanical brake 8), the electric motor 6 is actuated in step S9 to accelerate the work machine 2. Here, the actuation in step S9 is dependent on step S8 (in which it is detected whether the current and the desired driving directions are different).
[0039] List of reference signs
[0040] 2 Work machine
[0041] 4 Battery
[0042] 6 Electric motor
[0043] 8 Mechanical brake
[0044] 10 Pedal
[0045] 12 Driving direction switch
[0046] 14 Control device (of the drive assembly)
[0047] 16 Vehicle control device
[0048] 18 Drive assembly
[0049] S1 (Step) Detect information on the driving instruction
[0050] S1.1 (Step) Detect position information of the pedal
[0051] S1.2 (Step) Detect position information of the driving direction switch
[0052] S2 (Step) Detect information on the maximum charging current
[0053] S3.1 (Step) Determine information on the desired braking torque
[0054] S3.2 (Step) Determine the desired driving direction
[0055] S3.3 (Step) Determine the driving requirement
[0056] S4 (Step) Determine information on the maximum braking torque of the electric motor
[0057] S5 (Step) Compare the information of the desired braking torque with the information of the maximum braking torque
[0058] S6 (Step) Send a signal for driving and controlling the mechanical brake
[0059] S7 (Step) Drive and control the motor for regeneration
[0060] S8 (Step) Detect the information of the current driving direction
[0061] S9 (Step) Drive and control the motor to accelerate the working machine
[0062] A (Axis) State of charge of the battery
[0063] B (Axis) Charging or discharging power of the battery
[0064] C (Curve) Charging power of the battery
[0065] D (Curve) Discharging power of the battery
[0066] E (Value) Minimum state of charge of the battery for discharging
[0067] F (Value) Maximum state of charge of the battery for optimizing the charging power
[0068] G (Value) Maximum state of charge of the battery for charging by regeneration
[0069] H (Value) Maximum state of charge of the battery for charging
[0070] I (Value) Maximum state of charge of the battery
Claims
1. A method for controlling the driving behavior of a work machine (2), wherein, the work machine (2) has a battery (4), an electric motor (6) for propelling the work machine (2), and a mechanical brake (8), wherein the electric motor (6) is configured to charge the battery (4) with a charging current by means of regeneration, and wherein the method has the following steps: detecting (S1) information of a driver's driving instruction of the work machine (2), detecting (S2) information of the maximum charging current of the battery (4), determining (S3.1) information of a desired braking torque depending on the detected information of the driver's driving instruction, determining (S4) information of the maximum braking torque of the electric motor (6) depending on the detected information of the maximum charging current of the battery (4), comparing (S5) the information of the desired braking torque with the information of the maximum braking torque, and if the desired braking torque is greater than the maximum braking torque, sending (S6) a signal for controlling the mechanical brake (8).
2. The method according to claim 1, characterized in that, if the desired braking torque is greater than the maximum braking torque, the method includes: controlling (S7) the electric motor (6) to brake with a regenerative braking torque, and sending (S6) a signal for controlling the mechanical brake (8) includes sending a braking torque difference, wherein the braking torque difference is the difference between the desired braking torque and the regenerative braking torque.
3. The method according to claim 2, characterized in that, braking with the braking torque difference constantly over time by sending (S6) a signal for controlling the mechanical brake (8), and braking the electric motor (6) variably over time with the regenerative braking torque by controlling (S7).
4. The method according to any one of the preceding claims, characterized in that, detecting (S1) information of the driving instruction includes detecting (S1.1) position information of a pedal (10) and detecting (S1.2) position information of a travel direction switch (12).
5. The method according to claim 4, characterized in that, the method includes: determining (S3.2) a desired travel direction depending on the detected position information of the travel direction switch and detecting (S8) information of the current travel direction, wherein if the direction of the desired travel direction is different from the current travel direction, controlling (S9) the electric motor (6) to accelerate the work machine (2) in the direction of the desired travel direction.
6. The method according to claim 5, characterized in that, determining (S3.3) a travel requirement depending on the detected position information of the pedal (10) includes determining a travel speed.
7. The method according to any one of the preceding claims, characterized in that, sending (S6) a signal for controlling the mechanical brake (8) to a vehicle control device (16) for controlling the mechanical brake (8).
8. A control device (14), the control device being configured to implement the method for controlling the driving behavior of a work machine (2) according to any one of claims 1 to 7.
9. A drive assembly (18) having an electric motor (6) and a control device (14) according to claim 8.
10. A work machine (2) having a battery (4), a mechanical brake (8), a vehicle control device (16) for actuating the mechanical brake (8), and a drive assembly (18) according to claim 9.