Hoisting type battery box positioning and battery replacing system and vehicle battery replacing station

Abstract

The utility model relates to the technical field of battery swapping, and discloses a hoisting type battery box positioning and swapping system and a vehicle swapping station, the system comprises a distance measuring module which is installed at a first preset position in the swapping station and is used for detecting the distance between a battery box and the first preset position, and the first preset position comprises a plurality of preset points in the swapping station; the controller is in communication connection with the distance measuring module and the battery replacement moving module and used for obtaining the distance between the battery box and the first preset position, determining the actual position of the battery box according to the distance between the battery box and the first preset position and generating a control instruction according to the actual position of the battery box; and the battery replacement mobile module is used for replacing the battery according to the control instruction. The distance measuring module is used for measuring the distance between the battery box and the first preset position, then the actual position of the battery is determined, the recognition precision of the position of the battery box is improved, the battery replacement moving module is controlled to replace the battery according to the actual position of the battery, and the battery replacement efficiency and reliability are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery replacement, and in particular to a hoisting type battery box positioning and replacement system and a vehicle battery replacement station. Background Art

[0002] With the rapid development of new energy vehicles, charging time requirements are increasing, while charging facilities are also insufficient, making battery swapping technology a key development direction for the industry. Currently, battery swapping stations mainly offer several types of battery swapping methods, including top-mounted, chassis-mounted, and side-mounted. However, for top-mounted battery swapping, most systems currently on the market use cameras to identify the battery compartment position. However, this method is significantly affected by the lighting environment. In poor lighting conditions, the battery compartment position cannot be accurately identified, resulting in large errors in battery compartment position recognition, making automatic battery swapping impossible. Utility Model Content

[0003] In view of this, the present invention provides a hoisting battery box positioning and battery replacement system and a vehicle battery replacement station to solve the problem that the battery box position cannot be accurately identified for battery replacement when the lighting environment is poor.

[0004] In the first aspect, the utility model provides a hoisting type battery box positioning and battery replacement system, the system includes: a distance measurement module, a controller, and a battery replacement mobile module, wherein:

[0005] a distance measuring module installed at a first preset position in the battery swap station and configured to detect the distance from the battery box to the first preset position, wherein the first preset position includes a plurality of preset points in the battery swap station;

[0006] a controller, which is in communication with the distance measurement module and the battery exchange mobility module, and is used to obtain the distance from the battery box to the first preset position, determine the actual position of the battery box based on the distance from the battery box to the first preset position, and generate a control instruction based on the actual position of the battery box;

[0007] The battery replacement mobile module is installed at the second preset position on the top of the battery replacement station and is used to replace batteries according to control instructions.

[0008] The utility model provides a hoisting battery box positioning and battery replacement system, which uses a ranging module to measure the distance from the battery box to a first preset position, and then determines the actual position of the battery, thereby improving the recognition accuracy of the battery box position, and controlling the battery replacement mobile module to replace the battery according to the actual position of the battery, thereby improving the efficiency and reliability of automatic battery replacement.

[0009] In an optional embodiment, the distance measurement module includes a horizontal distance measurement unit and a vertical distance measurement unit, wherein:

[0010] A horizontal distance measuring unit is installed at a first preset sub-position on the top of the battery swap station and is used to detect the distance from the battery box to the first preset sub-position on the top;

[0011] A vertical distance measuring unit is installed at a second preset sub-position on the inner side of the battery swap station and is used to detect the distance from the battery box to the second preset sub-position on the side.

[0012] The utility model provides a hoisting battery box positioning and battery replacement system, in which distance measuring units are respectively arranged on the top and side of the battery replacement station, which is conducive to accurately positioning the horizontal and vertical positions of the battery box in the battery replacement station and improving the positioning accuracy of the battery box.

[0013] In an optional embodiment, the horizontal distance measuring unit includes a plurality of infrared laser distance measuring sensors, the first preset sub-position includes a plurality of first preset measurement points, and each infrared laser distance measuring sensor is installed at a different first preset measurement point, for measuring the distance from the battery box to each first preset measurement point;

[0014] The vertical ranging unit includes multiple infrared laser ranging sensors, the second preset sub-position includes multiple second preset measurement points, and each infrared laser ranging sensor is installed at a different second preset measurement point to measure the distance from the battery box to each second preset measurement point.

[0015] The utility model provides a hoisting battery box positioning and battery replacement system, which uses multiple infrared laser ranging sensors to measure the distance from the battery box to each preset measurement point. It is not affected by the lighting environment, and the distance measurement is more accurate, thereby improving the positioning accuracy of the battery box.

[0016] In an optional embodiment, the battery exchange mobile module includes: a track-guided vehicle and a manipulator, wherein:

[0017] Track-guided vehicle, used to drive the manipulator to move according to control instructions;

[0018] The robot arm is used to change its posture according to control instructions and pick up and place batteries.

[0019] The utility model provides a hoisting battery box positioning and battery replacement system, which utilizes a rail-guided vehicle and a manipulator to cooperate in picking up and placing batteries, making it easy to adjust the position and posture of the batteries, allowing the batteries to enter and exit the battery box more smoothly, thereby improving the reliability of battery replacement.

[0020] In an optional embodiment, determining the actual position of the battery box according to the distance from the battery box to the first preset position includes:

[0021] Establish a coordinate system with the horizontal direction of the top of the battery swap station as the X-axis, the vertical direction of the inner side of the battery swap station as the Y-axis, and the direction of vehicles entering and exiting the battery swap station as the Z-axis;

[0022] Determine the distance from the battery box to the entrance of the battery swap station in the Z-axis direction, the first angle between the battery box and the X-axis, the second angle between the battery box and the Y-axis, and the third angle between the battery box and the Z-axis based on the distance from the battery box to each first preset measuring point and the distance from each second preset measuring point;

[0023] According to the distance from the battery box to each first preset measurement point, the distance from each second preset measurement point, the distance from the battery box to the entrance of the battery swap station in the Z-axis direction, the first angle between the battery box and the X-axis, the second angle between the battery box and the Y-axis, and the third angle between the battery box and the Z-axis.

[0024] The hoisting battery box positioning and battery replacement system provided by the utility model uses a controller to assist in determining the actual position of the battery box in the battery replacement station space. Data processing is faster and more accurate, thereby improving the speed and accuracy of battery box position detection.

[0025] In an optional embodiment, generating a control instruction according to the actual position of the battery box includes:

[0026] Determine the target position of the track-guided vehicle and the target posture of the manipulator based on the actual position of the battery;

[0027] A control instruction for the track-guided vehicle is generated according to the target position of the track-guided vehicle, and a control instruction for the manipulator is generated according to the target posture of the manipulator.

[0028] The utility model provides a hoisting battery box positioning and battery replacement system, which utilizes a controller to generate control instructions for the track-guided vehicle and the manipulator respectively, eliminating the need for the track-guided vehicle or the manipulator to judge their own actions, thereby improving control efficiency and battery replacement efficiency.

[0029] In a second aspect, the present invention provides a vehicle battery swap station, which includes: the hoisting battery box positioning and battery swap system of any one of the first aspects.

[0030] The vehicle battery swap station provided by the present invention utilizes the hoisting battery box positioning and battery swap system of any one of the first aspects, thereby avoiding the influence of the lighting environment on the battery position detection, improving the detection accuracy of the battery box position, and improving the reliability of battery swapping. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 This is a structural diagram of a hoisting type battery box positioning and battery replacement system according to an embodiment of the present utility model;

[0033] Figure 2 It is a structural schematic diagram of another hanging type battery box positioning and battery replacement system according to an embodiment of the utility model;

[0034] Figure 3 It is a schematic diagram of the structure of the battery box and the angles of each axis in the established coordinate system in the lifting battery box positioning and battery replacement system according to an embodiment of the present invention;

[0035] Figure 4 It is a structural schematic diagram of a vehicle battery swap station according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0036] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0037] An embodiment of the utility model provides a hoisting battery box positioning and battery replacement system and a vehicle battery replacement station. The distance from the battery box to a first preset position is measured by a ranging module, and then the actual position of the battery is determined. The battery replacement mobile module is controlled to replace the battery according to the actual position of the battery, so as to achieve the effect of improving the recognition accuracy of the battery box position and the reliability of battery replacement.

[0038] According to an embodiment of the present utility model, a system for positioning and replacing a battery box with a hoisting type is provided. Figure 1 This is a structural diagram of a hoisting type battery box positioning and battery replacement system according to an embodiment of the present utility model. Figure 1 As shown, the hoisting battery box positioning and battery replacement system includes: a distance measurement module 1, a controller 2, and a battery replacement mobile module 3, wherein:

[0039] like Figure 1 As shown, the distance measuring module 1 is installed at a first preset position in the battery swap station and is used to detect the distance from the battery box 4 to the first preset position. The first preset position includes multiple preset points in the battery swap station.

[0040] Specifically, the ranging module 1 includes multiple distance measuring devices installed at multiple preset points. Each distance measuring device can measure the distance from the battery box 4 to the corresponding preset point to obtain the distance from the battery box 4 to the first preset position. Since the battery swap station and the ranging module 1 are fixed, the battery swap station coordinate system is established with the horizontal direction of the battery swap station as the X-axis, the vertical direction as the Y-axis, and the vehicle entry and exit direction as the Z-axis. The first preset position of the ranging module 1 has at least two preset points in the X-axis direction and at least two preset points in the Y-axis direction. Therefore, the specific actual position of the battery box 4 in the battery swap station can be determined according to the distance from the battery box 4 to the first preset position.

[0041] like Figure 1 As shown, the controller 2 is respectively connected to the distance measuring module 1 and the battery replacement mobile module 3, and is used to obtain the distance from the battery box 4 to the first preset position, and determine the actual position of the battery box 4 based on the distance from the battery box 4 to the first preset position, and generate a control instruction based on the actual position of the battery box 4.

[0042] Specifically, the controller 2 is connected to the distance measuring module 1 to obtain the distance from the battery box 4 to the first preset position, and uses the built-in algorithm to calculate the actual position of the battery box 4 in the battery swap station based on the distance from the battery box 4 to the first preset position, including the distance in the X, Y, and Z axis directions in the battery swap station coordinate system and the angles between the planes of the battery box 4 and the X, Y, and Z axis directions. According to the actual position of the battery box 4, the coordinate transformation calculation is used to obtain the control instructions of the point-changing mobile module. The built-in algorithm of the controller 2 can be an existing mature technology to realize the confirmation of the actual position of the battery box 4 and the generation of control instructions, which will not be repeated here.

[0043] like Figure 1 As shown, the battery replacement mobile module 3 is installed at a second preset position on the top of the battery replacement station and is used to replace batteries according to control instructions.

[0044] Specifically, the battery swapping mobile module 3 moves from its current position according to the control instructions, moves to a position within the battery swapping station space that is convenient for battery access, and replaces the battery according to the control instructions. The specific process can be moving from the current position to the battery replacement position included in the control instructions, then removing the old battery and placing it in the old battery placement position, then moving from the old battery placement position to the new battery placement position, grabbing the new battery and moving it again to the battery replacement position, and placing the new battery into the battery box 4 to complete the automatic battery replacement.

[0045] The hoisting battery box positioning and battery replacement system provided in this embodiment uses a ranging module 1 to measure the distance from the battery box 4 to a first preset position, thereby determining the actual position of the battery, thereby improving the accuracy of identifying the position of the battery box 4, and controlling the battery replacement mobile module 3 to replace the battery according to the actual position of the battery, thereby improving the efficiency and reliability of automatic battery replacement.

[0046] In some optional embodiments, such as Figure 2 As shown, the distance measuring module 1 includes a horizontal distance measuring unit 11 and a vertical distance measuring unit 12 .

[0047] like Figure 2 As shown, the horizontal distance measuring unit 11 is installed at the first preset sub-position on the top of the battery swap station, and is used to detect the distance from the battery box 4 to the first preset sub-position on the top.

[0048] like Figure 2 As shown, the vertical distance measuring unit 12 is installed at a second preset sub-position on the inner side of the battery swap station, and is used to detect the distance from the battery box 4 to the second preset sub-position on the side.

[0049] Specifically, the first preset sub-position includes multiple preset points on the top of the battery swap station, each of which is on a straight line parallel to the X-axis. A distance measuring device is installed at each preset point to measure the distance from the battery box 4 to each preset point on the top of the battery swap station, which serves as the distance from the battery box 4 to the second preset position on the top. The second preset sub-position includes multiple preset points on the inner side of the battery swap station, each of which is on a straight line parallel to the Y-axis. A distance measuring device is installed at each preset point to measure the distance from the battery box 4 to each preset point on the inner side of the battery swap station, which serves as the distance from the battery box 4 to the second preset position on the side.

[0050] The hoisting battery box positioning and battery replacement system provided in this embodiment has distance measuring units set on the top and sides of the battery replacement station, which is conducive to accurately positioning the horizontal and vertical positions of the battery box 4 in the battery replacement station, thereby improving the positioning accuracy of the battery box 4.

[0051] In some optional embodiments, such as Figure 2 As shown, the horizontal ranging unit 11 includes multiple infrared laser ranging sensors, the first preset sub-position includes multiple first preset measuring points X1, X2, X3, ..., Xn, and each infrared laser ranging sensor is installed at a different first preset measuring point, respectively, for measuring the distance from the battery box 4 to each first preset measuring point.

[0052] like Figure 2 As shown, the vertical ranging unit 12 includes multiple infrared laser ranging sensors, the first preset sub-position includes multiple second preset measuring points Y1, Y2, Y3, ..., Yn, and each infrared laser ranging sensor is installed at a different second preset measuring point, respectively, for measuring the distance from the battery box 4 to each second preset measuring point.

[0053] Specifically, the distance measurement device uses an infrared laser ranging sensor, which is unaffected by external lighting conditions when detecting distance. The plurality of first preset measurement points are located on a straight line parallel to the X-axis. The number of first preset measurement points may be five, by way of example only, but not limitation. The plurality of second preset measurement points are located on a straight line parallel to the Y-axis. The number of second preset measurement points may be five, by way of example only, but not limitation.

[0054] The hoisting battery box positioning and battery replacement system provided in this embodiment uses multiple infrared laser ranging sensors to measure the distance from the battery box 4 to each preset measurement point. It is not affected by the lighting environment and the distance measurement is more accurate, thereby improving the positioning accuracy of the battery box 4.

[0055] In some optional embodiments, such as Figure 2 As shown, the battery-swapping mobile module 3 includes: a track-guided vehicle 31 and a manipulator 32 .

[0056] like Figure 2 As shown, the track-guided vehicle 31 is used to drive the manipulator 32 to move according to control instructions.

[0057] Specifically, the rail-guided vehicle 31 is installed on the top of the battery swap station and can move linearly along the X-axis, Y-axis, and Z-axis directions in the three-dimensional space of the battery swap station. A manipulator 32 is fixed on it to drive the manipulator 32 to move.

[0058] like Figure 2 As shown, the manipulator 32 is used to change its posture according to control instructions and pick up and place batteries.

[0059] Specifically, the track-guided vehicle 31 has low movement accuracy and flexibility, and cannot adjust the posture of picking up and placing batteries according to the angle of the battery box 4. Therefore, the track-guided vehicle 31 drives the manipulator 32 to move in a large range. After reaching the appropriate position, the manipulator 32 changes its posture according to the control instructions so that the angle at which the manipulator 32 picks up and places the batteries matches the current position of the battery box 4, avoiding collision between the batteries and the battery box 4 during the process of picking up and placing the batteries, or even making it impossible to pick up and place the batteries.

[0060] The hoisting battery box positioning and battery replacement system provided in this embodiment utilizes a rail-guided vehicle 31 and a manipulator 32 to cooperate in picking up and placing batteries, making it easy to adjust the position and posture of the batteries, allowing the batteries to enter and exit the battery box 4 more smoothly, thereby improving the reliability of battery replacement.

[0061] In some optional embodiments, determining the actual position of the battery box 4 according to the distance from the battery box 4 to the first preset position includes:

[0062] Step a1: Establish a coordinate system with the horizontal direction of the top of the battery swap station as the X-axis, the vertical direction of the inner side of the battery swap station as the Y-axis, and the direction of vehicles entering and exiting the battery swap station as the Z-axis.

[0063] Specifically, the X-axis and the Y-axis are in the same plane, and the origin of the coordinate system can be set in the battery swap station where the X-axis and the Y-axis intersect, and the Z-axis direction points to the direction in which the vehicle enters the battery swap station. This is only an example, but not limited to this.

[0064] Step a2, based on the distance from the battery box 4 to each first preset measurement point and the distance from each second preset measurement point, determine the distance from the battery box 4 to the entrance of the battery swap station in the Z-axis direction, the first angle between the battery box 4 and the X-axis, the second angle between the battery box 4 and the Y-axis, and the third angle between the battery box 4 and the Z-axis.

[0065] Specifically, the first preset position includes multiple first preset measurement points and multiple second preset measurement points. Taking 5 first preset measurement points and 5 second preset measurement points as an example, the schematic diagram of the angle between the battery box 4 and each axis of the coordinate system is as follows: Figure 3 As shown, the first angle between the battery box 4 and the X-axis is determined according to the distance from the battery box 4 to each first preset measuring point. For example, there are five first preset measuring points X1, X2, X3, X4, and X5. The distances between the battery and each first preset measuring point measured by the infrared laser ranging sensor are: x1, x2, x3, x4, and x5, respectively. Then, the tangent of the first angle A is calculated in the simplest way as In the formula, X2 and X1 represent the distances from point X2 and point X1 to the origin of the coordinate system, respectively. It should be noted that, after the first angle is calculated using multiple points, the average value can be calculated to make the calculation result more accurate. According to the distance from the battery box 4 to each second preset measurement point, the second angle between the battery box 4 and the Y axis is determined. The calculation process is the same as the process of determining the first angle between the battery box 4 and the X axis according to the distance from the battery box 4 to each first preset measurement point, which will not be repeated here. According to the shape and size of the battery box 4 itself, using mature existing technologies, combined with the first angle between the battery box 4 and the X axis, the second angle between the battery box 4 and the Y axis, the distance from the battery box 4 to each first preset measurement point, and the distance from the battery box 4 to each second preset measurement point, the distance from the battery box 4 to the entrance of the battery swap station in the Z axis direction and the third angle between the battery box 4 and the Z axis can be determined. The specific process is the same and will not be repeated here.

[0066] Step a3, determine the actual position of the battery box 4 in the battery swap station based on the distance from the battery box 4 to each first preset measurement point, the distance from each second preset measurement point, the distance from the battery box 4 to the entrance of the battery swap station in the Z-axis direction, the first angle between the battery box 4 and the X-axis, the second angle between the battery box 4 and the Y-axis, and the third angle between the battery box 4 and the Z-axis.

[0067] Specifically, since the relative position of the coordinate system and the battery swap station is fixed, the position of the battery box 4 in the coordinate system is determined. Then, the coordinate transformation relationship is combined with the relative position relationship between the coordinate system and the battery swap station to obtain the actual position of the battery box 4 in the battery swap station. The specific process is a mature existing technology and will not be repeated here. If the coordinate system is exactly the same as the coordinate system of the battery swap station, step a3 can be omitted.

[0068] The hoisting battery box positioning and battery replacement system provided in this embodiment uses the controller 2 to assist in determining the actual position of the battery box in the battery replacement station space. Data processing is faster and more accurate, thereby improving the speed and accuracy of battery box position detection.

[0069] In some optional embodiments, generating a control instruction according to the actual position of the battery box 4 includes:

[0070] The target position of the track-guided vehicle 31 and the target posture of the manipulator 32 are determined according to the actual position of the battery box 4 .

[0071] A control instruction for the track-guided vehicle 31 is generated according to the target position of the track-guided vehicle 31 , and a control instruction for the manipulator 32 is generated according to the target posture of the manipulator 32 .

[0072] Specifically, based on the actual position of the battery box 4 in the battery swap station, the target position of the rail-guided vehicle 31 and the target posture of the manipulator 32 are determined, and then the motion trajectory of the rail-guided vehicle 31 is planned according to the target position of the rail-guided vehicle 31 to generate control instructions for the rail-guided vehicle 31, and the motion trajectory of the manipulator 32 is planned according to the target posture of the manipulator 32 to generate control instructions for the manipulator 32.

[0073] In a specific embodiment, when a heavy truck to be replaced enters the battery replacement station, the position of the heavy truck to be replaced will deviate slightly when entering the battery replacement station. The planes of the battery box 4 of the heavy truck to be replaced do not completely coincide with the X, Y, and Z axes, but have an angle with each axis in the coordinate system. Among them, the angle between the plane of the battery box 4 and the X and Z axes has the greatest impact. At this time, the distance between each point of the battery before replacement is measured by an infrared laser rangefinder and the angle with each direction is calculated to determine the specific position and angle of the battery box 4. When the manipulator removes the old battery and replaces the heavy truck with another fully charged battery, the three angles calculated above are used to control the clamping angle and direction to complete the battery replacement of the heavy truck to be replaced.

[0074] The hoisting battery box positioning and battery replacement system provided in this embodiment uses the controller 2 to generate control instructions for the track-guided vehicle 31 and the manipulator 32 respectively, eliminating the need for the track-guided vehicle 31 or the manipulator 32 to judge their own actions, thereby improving control efficiency and battery replacement efficiency.

[0075] In this embodiment, a vehicle swap station is provided, such as Figure 4 As shown, the vehicle battery swap station includes: any one of the hoisting battery box positioning and battery swapping systems in the previous embodiment.

[0076] The vehicle battery swap station provided in this embodiment utilizes the hoisting battery box positioning and battery swap system of any one of the first aspects, thereby avoiding the influence of the lighting environment on the battery position detection, improving the detection accuracy of the battery box position, and improving the reliability of battery swapping.

[0077] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A hoisting battery box positioning and battery replacement system, characterized in that: The system includes: a distance measurement module, a controller, and a battery replacement module, wherein: a distance measuring module installed at a first preset position in the battery swap station, and configured to detect the distance from the battery box to the first preset position, wherein the first preset position includes a plurality of preset points in the battery swap station; a controller, which is in communication with the distance measurement module and the battery exchange mobility module, and is used to obtain the distance from the battery box to the first preset position, determine the actual position of the battery box based on the distance from the battery box to the first preset position, and generate a control instruction based on the actual position of the battery box; The battery replacement mobile module is installed at the second preset position on the top of the battery replacement station and is used to replace batteries according to control instructions.

2. The system according to claim 1, wherein: The distance measurement module includes a horizontal distance measurement unit and a vertical distance measurement unit, wherein: A horizontal distance measuring unit is installed at a first preset sub-position on the top of the battery swap station and is used to detect the distance from the battery box to the first preset sub-position on the top; A vertical distance measuring unit is installed at a second preset sub-position on the inner side of the battery swap station and is used to detect the distance from the battery box to the second preset sub-position on the side.

3. The system according to claim 2, characterized in that The horizontal distance measuring unit includes a plurality of infrared laser distance measuring sensors, the first preset sub-position includes a plurality of first preset measuring points, and each infrared laser distance measuring sensor is installed at a different first preset measuring point, for measuring the distance from the battery box to each first preset measuring point; The vertical ranging unit includes multiple infrared laser ranging sensors, the second preset sub-position includes multiple second preset measurement points, and each infrared laser ranging sensor is installed at a different second preset measurement point to measure the distance from the battery box to each second preset measurement point.

4. The system according to claim 1, wherein: The battery-exchange mobile module includes: a track-guided vehicle and a manipulator, wherein: The track-guided vehicle is used to drive the manipulator to move according to control instructions; The manipulator is used to change its posture according to control instructions and pick up and place batteries.

5. A vehicle swap station, characterized in that: The vehicle battery swap station includes: the hoisting battery box positioning and battery swap system described in any one of claims 1-4.

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